CAD the SIMPLAE: Simplified

A Note:

This Instructable is the simplified version of the complete one, which you can find in my profile (if it is not there, it's not finished yet). The full version takes a detailed, step by step approach, instructing you through every single part of the process. However, that version ended up being extremely long and tedious to read through, which is why this version exists. This version will also be my submission to the Make it Resilient 2024 contest.

Introduction:

Hi! My name is Maximus, and I am a grade 12 student in Toronto, Ontario. As a student who wants to go into engineering, I thought the Make it Resilient 2024 challenge would be a great opportunity for me to practice my CAD skills, while learning lots of new things about design challenges, architecture, and even the very environment I live in!

During this challenge, I went through a lot of difficulties. For example, I struggled a lot with creating a balance between quality of the habitat, and cost-effectiveness, such that the habitat is both safe to use and practical to make. I also struggled a lot with the CAD process itself, since I have never actually used AutoCAD's software before. However, I still felt like I learned a lot, all while having fun: and as you follow along with this Instructable, I hope you do too!

Product Introduction:

That's all fine and good, but what really is the SIMPLAE? Well, the concept behind the SIMPLAE, or the Self-constructing Integrated Modular Platform for Long-term use and Assistance with Emergencies (yes, it's a mouthful), is all about versatility and resilience in any situation -- although its greatest strengths become apparent in disaster relief. The SIMPLAE itself is based off of modern life rafts, and it is a tent-like structure which floats on water, designed with a few extra, but significant features. Being self-constructing means that SIMPLAE requires minimal human labour, keeping humans safe in otherwise dangerous environments. It also means that the habitat can be stored and transported extremely compactly, making it great for mass deployment and also personal use. The fact that the SIMPLAE is modular and can be connected to other units creates a great degree of flexibility, where single units can be used to house a family, while larger interconnected structures can be used as headquarters for disaster relief, long-term research, or even simply housing a community. Finally, the SIMPLAE comes with many design points that allow it to be modified for any situation, while also allowing long-term use. For example, the tarp of the "tent" is designed to be easily replaceable, allowing stronger walls to be installed for reinforcement, extra insulation for cold environments, thinner tarp for hot environments, and much more! The SIMPLAE is also specifically designed such that solar panels, measuring instruments, living appliances, and more can be easily installed to suit the user's needs. Although these elements WILL require human labour, they are all designed to be installed easily and quickly, sparing human resources as much as possible.

You can see a demonstration of the different parts CADed in this tutorial in the video above, using an animation made in Fusion 360.

Format:

This Instructable is split into 5 chapters. Chapter 1 is all about the design process: how the idea was formulated, the revisions that it went through, and why the final version was selected. Chapter 2 is about the CAD of the parts themselves, including the mechanism, the exterior, and the container. Chapter 3 is about the simulations used to test the design, and Chapter 4 is about how the SIMPLAE might be used in real life. Finally, Chapter 5 is about analyzing the design, and final thoughts. The table of contents is listed below:

• Chapter 1: Design Process
• Step 2: Brainstorming
• Step 3: Planning and Sketching
• Step 4: Revise, revise, revise!
• Step 5: Experimentation
• Chapter 2: The CAD
• Step 7: Tips & Tricks for Kicks
• Step 8: The Mechanism
• Step 9: The Exterior
• Step 10: The Container
• Chapter 3: Simulations
• Step 12: How to Simulate
• Step 13: Floors
• Step 14: More Floors
• Step 15: ...And Even More Floors
• Step 16: The Mechanism
• Step 17: Wind Testing
• Chapter 4: Real-Life Use
• Step 19: Single Family Temporary Shelter
• Step 20: The Inside
• Step 21: Disaster-Relief Base of Operations
• Step 22: The Washroom/Storage
• Step 23: The Medical Room
• Step 24: The Common Room
• Step 25: The Dock
• Step 26: The Work Room
• Step 27: The Break Room
• Chapter 5: Analysis and Conclusions
• Step 29: Power
• Step 30: Water
• Step 31: Safety
• Step 32: Mental Health
• Step 33: Sustainability
• Step 34: Miscellaneous
• Step 35: Conclusions
• Step 36: Bibliography

Credits:

This project would not have been possible without the help of others. Although all the ideas and work were done by me, I have to give thanks to my family, for their endless support and encouragement. Furthermore, I have to thank the Aurelia Institute whose work inspired this -- which is why its name is a homage to their TESSERAE (a 4-simplex is a tesseract with less sides). Additionally, thank you to Autodesk and the judging panel for this wonderful opportunity, and especially to Autodesk for allowing free use of their tools to students like me. And of course last but not least, thank you, dear reader, for your time!

• Autodesk Fusion
• If you are a student, this (and other Autodesk products) is completely free with an education account!
• Autodesk CFD (Optional)
• Many, many CAD models. A full list crediting all the models I used will be at the end of this Instructable.

In this chapter, I will guide you through the design process which was used to create the SIMPLAE. Note that while this chapter is dedicated to the design process, in reality the design process occurs all throughout the entire Instructable, with constant revisions, new ideas, and experimentations. Certain parts of the design process have merely been gathered into this chapter, for your ease of viewing.

Any good project begins with a brainstorm, and this one is no different. The first thing that I did was make a mind map, with all the aspects and difficulties of the prompt which I would have to consider. After this, I began researching more about the TESSERAE pavilion which was given to us contestants as a source of inspiration, I was deeply fascinated in its design. After listening to a podcast which Annika Rollock (the director of engineering at Aurelia Institute) participated in, she greatly inspired me to the potential of self-constructing habitats. She argued that by using self-assembling technology, human labour for construction could be greatly reduced. In extreme environments -- especially space -- reducing human labour means greater safety to the people involved, and also increased efficiency and reduced costs. Because of this, I decided that I wanted to apply the same kind of self-constructing technology into Earth, rather than space. By using this on Earth, a habitat could be quickly, safely, and cheaply constructed in situations where they are desperately needed: most notably, after/during a disaster, such as flooding or war. A self-constructing habitat could also be used in locations which are hard to work in, such as the arctic or the desert, allowing for efficient research and exploration. Thus, the idea behind the SIMPLAE was born.

Now that I had a destination in mind, it was time to think about how I was going to achieve it. Because of the gravity on Earth, it was infeasible to use magnets to construct a habitat, like TESSERAE does, so a different approach needs to be used. Furthermore, using the SIMPLAE for disaster relief means that it comes with further constraints: it must be compact before construction, so that it can be flown out and airdropped in large amounts. Furthermore, it must be able to float on water, to deal with flooding situations, and it must be resistant to extreme conditions including: extreme cold, extreme heat, strong rain, wind, snow, and more! Covering all these use cases at once would be nearly impossible, which is why a large focus of the SIMPLAE is adaptivity and customizability.

To simplify the question a bit, I first decided to focus on the first three constraints: being self-constructing, compact, and able to float on water. With these ideas, an obvious contender emerged: life-rafts! Collapsible life-rafts fit into all three of these constraints, and have years of research and development into their technology. With this in mind, I began to research the technology behind how life-rafts work.

After some google searches, I found out that life-rafts inflate by using large amounts of compressed CO2 and N2 gas. These gasses are used because they can be easily compressed, making them ideal for compactness. When the life-raft is triggered to open, the compressed gas is released into the raft, quickly expanding it into a boat form. Thus, by using compressed gas, the raft essentially "self-constructs", which is exactly what I sought out to do. This is what inspired and eventually became my first iteration of the SIMPLAE.

Now that an idea was fleshed out, it was time to begin working out the details. I first began by sketching a rough idea of what the raft would look like: note that this sketch does not have many details and it looks pretty bad, as this is solely for conceptualizing. This allowed me to better visualize what would need to happen for the habitat to properly expand. For instance, something I did not consider while brainstorming was the fact that a shelter expanded by gas would need to be almost entirely made out of flexible materials -- not wood or steel, as traditional houses use. This makes it difficult to create expandable habitats that can resist harsh environments, such as extreme wind or heavy snow.

With an image in mind of what the first iteration of the SIMPLAE might look like, it was now time to analyze the strengths and weaknesses of this design, and highlight the strengths while getting rid of the weaknesses. Here's a basic overview of my own conclusions, looking at the first design:

Strengths

• Very compact
• Mechanically simple
• Fast
• Cheap
• Good in water

Weaknesses

• Wall material too weak
• Wall material not very resistant to weather
• Cannot be modified (For example, you cannot add another entrance to the habitation without completely puncturing it)
• Not modular (Cannot connect multiple of them together)

Now, with these points in mind, it was time to start brainstorming again!

Iteration 3

The thought process behind this iteration was to fix the previous iterations' problems, and make a habitat which could be modified and customized to the owner's needs. In this way, the habitat could be much more resilient in a variety of situations, with a variety of use-cases: researchers could install solar panels to power their equipment, while emergency responders could install insulation to keep out the cold. Being customizable would solve most of the issues with the habitat, seeing as the habitat itself could be modified to fit in any environment. In order to create this sort of customizability, the habitat would require some sort of frame, such that things could be easily installed and removed. After some searching, I stumbled across the idea behind this iteration: umbrellas! Umbrellas, especially foldable umbrellas, are very compact when closed, but can expand and "self-construct" in seconds! By essentially creating a large umbrella, a "tent" can also be constructed in seconds.

Strengths

• Compact
• Fast
• Has a frame (therefore is customizable!)

Weaknesses

• More mechanically complicated
• Very bad in water
• Does not have a floor!
• Because of the way an umbrella folds, the "floor" would need to be made out of some sort of stretchy material, or else not exist at all -- certainly not adequate for extreme environments.
• Hence it is VERY bad in water

Iteration 4 (Current Iteration)

The thought process behind this iteration was to use the strengths of iteration 1 and iteration 3 together, to cancel out both their weaknesses. The largest issue with iteration 4 was that its floor would have to be very thin and non-buoyant, while the largest strength of iteration 1 was that it was very buoyant, if nothing else. Thus, the obvious solution was to combine the both, and use a umbrella-folding mechanism for the "tent" of the habitat, and a compressed gas mechanism for the "floor" of the habitat. The final analysis of this iteration came out to this:

Strengths

• Compact
• Fast
• Customizable
• Good in water

Weaknesses

• Mechanically complicated

As you can see, this iteration has mitigated all the major weaknesses (that I could think of), which is why it is currently the final iteration of SIMPLAE, and the version which we will be CADing in this tutorial.

A note:

I settled on using the hexagonal shape for base of the SIMPLAE, due to its ability for modularization -- just like how hexagons can be stacked in a honeycomb. Furthermore, hexagons strike a good balance between efficient use of space, minimal surface area, and an even distribution of pressure.

With a solidified concept in mind, it was time to start experimenting with the basic mechanisms, to see how it would actually work. Looking back now, I'm glad that I did this, because it ultimately saved lots of time by helping me plan better and warning me in advance of any potential issues.

Since this experimentation is not an actual part of the CAD, and merely a preparation step, I won't be sharing how I made these mock-ups. Instead, I'll share the recordings of what I found, and my conclusions. You can find all of the recordings in the videos above, and all the conclusions below.

But first of all, how was experimentation even conducted? Well, the first stage was simple: all I did was create a simple mock-up of the umbrella mechanism, which I was aiming to use. This allowed me to scout out any potential issues which might show up while CADing the final design. And show up they did, because I almost immediately realized the problem: it was almost impossible to predict how the mechanism would move! Because the mechanism would be CADed in a semi-open state, I couldn't accurately predict what it would look like when it was eventually closed and opened. This was a huge problem, because I needed fine control over the mechanism, in order to suit the SIMPLAE.

Thus, I began studying many different references to get an idea of what was going on. This video by "thang010146" on Youtube served as a great reference, and also inspired me to colour code my mock-ups. This allowed me to easily keep track of all the parts, with the difference pieces coloured: green, purple, orange, and blue.

Taking this idea even further, I began to experiment with how each piece effects the final result. First I made a simple version with pieces of random size. After that, I shortened each piece individually, and noted down how that affected the final result. These recordings are all in the video above, and here are my conclusions:

• Shortening blue leads to:
• A high angle when extended and
• A very compact form when retracted
• Shortening purple leads to:
• A very high angle when extended and
• A very uncompact form when retracted
• Shortening orange leads to:
• A very high angle when extended and
• A slightly compact form when retracted
• Shortening green leads to:
• A very low angle when extended and
• A slightly compact form when retracted.

Now, I applied this knowledge I found to the SIMPLAE itself. The requirements for the SIMPLAE are that it has a moderately low angle when extended (to form a "tent" shape), and a very compact form when retracted (to save space). Thus, I ended up shortening both green and blue from the initial model, ending up with a ratio of:

9 : 9 : 8.5 : 8.5

for

Green : Blue : Orange : Purple

I converted this to the appropriate dimensions for the real-scale SIMPLAE model, giving

720mm : 720mm : 680mm : 680mm

Keep in mind that these dimensions are merely those that I used, and you should feel free to experiment around with whatever dimensions you want, using the above results from my experimentation.

In this following chapter, I will guide you through the CAD of the SIMPLAE itself, including all the different parts. Please note that for all of the following parts, you can check my profile for more detailed instructions.

But first, here's some tips and shortcuts that I learned throughout my CADing journey, that might make your life a bit easier! You can skip this section if you are not interested though.

• When you are copy and pasting a part, remember the difference between "paste" and "paste new". If you use "paste", the resulting bodies will be irrevocably linked, so be careful!
• Always make new components for different parts, and make sure your components are properly named. Having organized components can make your task a lot less frustrating.
• If you need to fix a problem with your joint positioning but your collision groups are getting in the way, you can use "suppress collisions" to temporarily disable them.
• Rather than using fixed joints, try using fixed bodies instead! They effectively do the same thing, but using joints will lag your file more.
• Always be very careful with your joint placements! Being off by just a bit can mess up your entire build.
• Try to avoid using the "capture position" tool when you don't need to. Doing so too much will lag up your file.
• Press Shift + N to temporarily assign a different colour for each of your components. This makes it much easier to differentiate parts.
• You can also change the opacity of a component by right clicking it, if it is getting in your way.
• Going a step further, you can also use "Isolate" to completely hide all other components.
• You can use the "Intersections" inspection from the "Utilities" menu in order to find any intersections between parts. This can be very helpful when checking your work!
• If you want to select something, but it is covered by something else, just hold down left click! This will open a menu that lets you choose what you select.
• Press X while sketching to switch between construction mode.

The mechanism behind the SIMPLAE is essentially a larger umbrella. It uses a central sliding ring that is attached to 6 "arms". When the red ring (the "moving part") is positioned upwards, the arms will expand, and when the red ring is downwards, the arms will retract. The bottom half of the central pole is also retractable.

Here is a quick rundown on how to CAD this part:

1. Create a pole
2. Create 6 hinges, and attach them to the top of the pole
3. Create a ring with 6 hinges, and colour it red.
4. Connect the ring to the pole with a sliding joint
5. Create 4 different lengths of bars, which will serve as the arm parts
6. Connect these bars together using revolve joints
7. Modify the shape of the bars such that they do not intersect

Sadly, I was not able to figure out a way to let you actually move the mechanism in the demonstration below. However, feel free to download the model on your own to play with it if you like. You can also refer to the video at the top of this Instructable, to see how the mechanism moves.

A note:

In the video at the beginning of this Instructable, the container opens up with the mechanism completely unattached to anything else. This is because I could not find a satisfactory way to model and animate cloth physics, and in real life, the plastic "tent" and the deflated "floor" would both already be attached to the mechanism.

Moving on to the CAD of the exterior, .there are two main parts: the yellow "tent", and the orange "floor". However, there are also many smaller details, such as the handles to help people climb up, the arrows point towards the entrance, and the anchor points, where things can be tied to the SIMPLAE.

Here is a quick rundown on how to CAD this part:

1. For the tent, use the method shown in this video, by Youtuber "It's made EZy"
2. For the floors, simply create a hexagonal prism. Then, fillet the top and bottom, and then create a duplicate on top of it
3. For the pressure valves and the zipper, make use of different extrude types, especially "Extrude from Object"
4. For the handle, make use of the sweep tool

While everything else was CADed by me, the handle of the zipper was actually derived from another person's design, using Autodesk's community gallery, "Showcase it." This is important to note because in your own CAD, if there are parts which you deem too complicated, a good alternative is often to simply look for models online. Just make sure you credit your sources properly! All models used in this Instructable are available at the bottom.

A note:

The "floor" is actually made up of 2 materials, although that is hard to see from here. The exterior, floatation tubing is made out of flexible PVC, which is inflated using compressed gas. The hexagon inside of the tubing is made out of a foam composite. This ensures that the living area is insulated and comfortable for the inhabitants, while the exterior is as light as possible, to reduce weight.

When the SIMPLAE is in its closed form, it needs a container for transportation and for protection. This container is inspired by the design for modern liferafts, and it is simple, but effective.

Here is a quick rundown on how to CAD this part:

• Create a hollow cylinder
• Fillet the top and bottom
• Sketch and revolve to create the bumps on the sides.
• Use the emboss tool to create the text
• Follow this guide (from Autodesk themselves!) to create the handles

With the main CAD of the SIMPLAE complete, it is time to use an extremely valuable tool which Fusion 360 provides to us: simulations! By switching from the "Design" workspace into the "Simulation" workspace, you can use Fusion 360 to easily find how your model will react under real world conditions, and make adjustments from there. Especially since the SIMPLAE is designed for extreme environments, it is very important to ensure the structure is stable and strong. Furthermore, we can use these simulations to ensure the SIMPLAE can stand up to harsh conditions, such as strong wind and snowfall.

If you already feel comfortable in the Simulation workspace, feel free to skip this step, but if this is your first time creating a simulation, then this step is for you!

Although the Simulation workspace might seem intimidating from a first glance, it's not actually that hard. Here is a great video on how to use this workspace by Youtuber "Lars Christensen", and it's also the video that taught me how to do this! However, you can also follow along with the below information if you would like.

First of all, if your model is complicated, you might want to simplify it. Use the "Simplify Model" selection from the 1st image to adjust your model, deleting unnecessary faces and objects, until you are satisfied. Then, create the study that you want from the top left corner. I won't go over them all in this Instructable, but they come with great description texts, which I highly advise that you read through.

After creating your study, the Simulation workspace is super intuitive, in that you just need to go from left to right, across the toolbar, as shown in the 2nd image! Following the step numbers, first, enter the "Materials" tool to assign the necessary materials to your objects. The simulation will work best with rigid materials, such as metal or wood, but you can still get by with materials such as flexible PVC (which is what the SIMPLAE floor uses).

Next, use the "Constraints" tool to set up the constraints on your object: which are things that will limit the bodies motion, such as screws, walls, and floors. Then setup the force that will be exerted on your component, using the "Loads" tool. Next, press "Toggle Mesh Visibility" to generate the mesh, and then you are done the preparation! Now, simply use the "Pre-check" tool to make sure you aren't missing anything, and then hit "Solve". Finally, check your Simulation Results, and you are done!

First, we will create a simulation of the floor, to see how well it can handle the forces of the people moving on it, as well as all the furniture and such which will come with them.

The load I used was 10000 lbs of force. This is because U.S. building codes dictate that residential buildings must bear a minimum uniform live load of 40 lbs per square foot. Since the SIMPLAE is not designed to carry particularly heavy loads, this metric seemed fitting. Using the figure of 40 lbs per square foot, the floor would need to carry 9143.80 lbs of force, which I rounded up to 10000 lbs. Note that the material I used for the floor here was Expanded Polystyrene, since life raft floors are often made out of similar materials, due to the high compressibility and temperature insulation.

TIP:

In the above images, you might notice that the floor looks heavily deformed by the load on top of it, even though the simulation says the deformation is small! Don't worry, since this is because Fusion 360 automatically adjusts the visible deformation, to make it more apparent. To change this, simply click "Actual" from the "Deformation" panel. If you do so, you'll find that our floor is completely fine, and hardly deformed at all!

As shown in the 1st image, the floor is very well within acceptable safety, with a safety factor of 15.00. This means that this is practically no risk of the floor collapsing or breaking. In fact, this extremely high safety factor means that production costs (and environmental costs) could theoretically be reduced by using a different material; however, polystyrene's high compressibility and insulation make it the ideal material for this part.

Furthermore, the strain on the floor is extremely low, as shown in the 2nd image. Very few areas on the floor are under even moderate strain, which is reasonable and acceptable in this instance.

Finally, the displacement of the floor is extremely low, with a maximum of 0.07 mm.

Wait a second! Although the previous simulation is satisfactory for ordinary conditions, the SIMPLAE is specifically designed for extreme environments! With that being said, how does it hold up to an increased weight?

Well, the only environmental condition which will significantly increase the weight the floor experiences is... snow! Although rain might pool on the SIMPLAE, only a certain amount can stick to the sloped roof at a time, making the potential weight small in comparison. So, how much weight would snow really add?

According to CNN, the most snowfall recorded in the world 24 hours is approximately 100.8 inches. According to the Canadian government, "each inch of snow represents a load of about 1 to 1½ pounds per square foot." Using the conservative estimate of 1.5 lbs per square foot per inch, and adding this onto the previous 40 lbs per square foot, this gives a load of 191.2 lbs per sqare foot, or a total load of 43707.36 lbs of force. I rounded this figure up to 45000 lbs, just to be extra safe.

Using this value to create a new simulation, you might be surprised to find that the results hardly even changed! Despite the much larger load, the safety factor actually remained at a stable 15.00! In fact, the only significant change was the displacement, which increased to a maximum of 0.226 mm, which is still very small. Basically, this means that even if there were world record breaking snowfall on top of the SIMPLAE, the floor would still be able to handle the load, easily!

It is worth noting that this result is not actually very realistic, as it assumes that the SIMPLAE is resting on a solid surface. While this is perfectly acceptable for most situations, it does not account for what will happen when the SIMPLAE is floating in water.

So then, how much weight would the SIMPLAE be able to support on water? Thanks to my physics classes, I've learned that the buoyancy force is equal to -ρvg, where 'ρ' is the density of a fluid, 'v' is the volume displaced, and 'g' is the gravitational constant. Using the "Properties" tool shows that the volume of the floor is 2.119e10 cubic millimeters. Assuming the water is freshwater (since saltwater would give a higher buoyancy force), the equation gives a buoyancy force of 207662 N, meaning that approximately 21190 kg can be supported before sinking. Subtracting the weight of the SIMPLAE itself (4609 kg) gives a carrying load of 16581 kg. However, it is important to assign a carrying load under the maximum physical carrying load, in case of external factors. Thus, we will divide the carrying capacity by 1.5 and round down, to give a maximum carrying capacity of 11000 kg, or 24000 lbs.

This carrying capacity is more than sufficient for our needs, since it can support the 10000 lbs needed for regular use, along with 14000 lbs (~48 inches) of snow. Realistically, it would be almost impossible for 4 feet of snow to accumulate on the SIMPLAE, due to its sloped shape.

But just to make sure, let us inspect what the SIMPLAE can support without sinking, to ensure it is fit for daily use. In the image above, I have made a list of the items that might be used on a SIMPLAE unit.

Image Transcription:

Weight supported: Floor 11000 kg (16581 kg unadjusted)

Weight taken: Plant 5 kg, Lifejacket 10 kg, Computer 10 kg, TV 20 kg, Toilet 40 kg, Sink 50 kg, Sofa 80 kg, Human 150 kg, Table 250 kg, Ballast (x1) 2000 kg, Ballast (x3) 6000 kg

From this chart, it is evident that the buoyancy of the SIMPLAE is more than enough to support its contents. In fact, the buoyancy is so much more than necessary that it might risk becoming unstable, due to floating too high in the water. To counteract this problem, I added ballast bags to the bottom of the floor, as shown in the 2nd image. When the SIMPLAE is floating, the ballast bags will hang down and fill with water, increasing the effective weight and increasing stability. However, when the SIMPLAE is on land, the ballast bags will not get in the way of anything (due to being empty), making them the perfect solution for this issue.

Each ballast bag has a volume of 1.996e9 cubic millimeters, or approximately 2000 kg of water. This means with 3 bags, the carrying load of the SIMPLAE is reduced from 12000 kg to approximately 6000 kg (13000 lbs). This carrying capacity is still more than enough for normal function, while greatly increasing stability. If additional carrying capacity is necessary, the ballast bags can be released remotely.

You might notice from the 2nd image that the three ballast bags are close to the center, rather than on the edges. This might seem odd, since this reduces the torque the ballast bags provide, thus reducing their ability to counteract external forces. However, this design choice comes from the possibility that a ballast bag might be damaged. If this happened with the bags spread apart, the increased torque would work against the SIMPLAE, increasing instability and possibly flipping the entire unit. Placing the bags closer together solves this issue. Similarly, if more than 6000 kg needs to be carried on a single unit, the bags can be released individually, without worry of flipping.

Speaking of which, it is time to begin testing the top half of the SIMPLAE. Since this simulation is made up of multiple components, make sure that you use the "Bolt Connector" tool to connect them together! Note that I am only simulating one of the "arms" of the mechanism, since the arms are all identical.

First, let us first simulate the mechanism under a "normal" load of 40 lbs per square foot. This works out to 185.28 lbs of force, rounded up to 200 lbs. Note that this value is actually overkill, as the mechanism is not meant to support people or furniture. Similar to the floor, the mechanism ends up with a perfect 15.0 safety factors.

As shown in the 1st image, the maximum stress is concentrated around the bolts, which makes sense. These bolts are under 3.345 MPa of stress at the most, which is actually quite a lot. However, since Fusion uses the yield strength (the maximum load before deformation starts) as 207 MPa, this stress is still sufficiently low.

As shown in the 2nd image, the deformation is very small, with a maximum of 0.072 mm.

But what about once snow is added? After experimenting with the values, I found that a load of 4000 lbs would bring the minimum safety factor down to 3.09, which is just above the minimum threshold (3rd image). This translates to ~863 lbs per square foot, or over 540 inches of snow! At 4000 lbs, the stress and displacement both remain reasonable. at ~70 MPa and 1.443 mm respectively. Needless to say, the mechanism is more than strong enough to support the tent.

Something to note is that the only sections of the only sections of the mechanism with a safety factor under 15.0 were the screws: the metal bars are still extremely overengineered! For this reason, this led me to pursue using different, cheaper materials. In particular, aluminum is a strong candidate, for its comparable strength, while weighing around 1/3 of steel! Furthermore, aluminum is cheaper than steel, and it is also a green material, being widely and easily recyclable.

The 4th image shows the mechanism under 4000 lbs of force, using aluminum instead of steel. As you can see, the aluminum bars are still under almost no stress at all. Furthermore, both the safety factor and the displacement are still satisfactory, at ~4.4 and ~3.3 mm respectively, meaning aluminum is the perfect material to build the mechanism from.

With stress testing complete, I was curious as to how the SIMPLAE would react under extreme wind environments. For this, I used Autodesk CFD, which is another Autodesk product that specializes in simulations and fluids. I won't explain how to use CFD here, but this video is by Youtuber 'Shihao' is a great guide on how to get started.

The wind speed that I used was 50 miles per hour, since that is the threshold where structural damage first occurs, according to the national weather service.

As you can see in the 1st image, the majority of the shear stress due to the wind occurs on the sides of the tent, which makes sense. The maximum shear stress is 61.4457 dyne per square centimeter, which is an extremely small amount. Thus, the shear stress due to wind is generally insignificant.

But, how about the stress due to the force of the wind itself? For this, I went back to Fusion, and create a static stress simulation with the load coming from the side. This would simulate the force caused by wind pushing against the SIMPLAE mechanism.

According to the Arizona State University, the fastest wind speed ever recorded was 231 mph. This translates to approximately 140 lbs per square foot, or ~700 lbs of force on each mechanism arm.

As shown in the 2nd image, under these conditions, the arm still has a minimum safety factor of 6.131, which is well within acceptable limits. Furthermore, the maximum stress and displacement are both acceptable, being 44.9 MPa and 2.12 mm respectively. Thus, the mechanism can withstand extremely strong winds.

Just to make sure, I also ran some more simulations with the force coming from different directions. I have recorded the results below.

• 90 degrees X, 0 degrees Y, 0 degrees Z: Min. safety 6.13, Max. stress 44.9 MPa, Max. displacement 2.12 mm
• 90 degrees X, 45 degrees Y, 0 degrees Z: Min. safety 6.64, Max. stress 41.4 MPa, Max. displacement 9.08 mm
• 60 degrees X, 0 degrees Y, 0 degrees Z: Min. safety 7.06, Max. stress 38.9 MPa, Max. displacement 2.07 mm
• 60 degrees X, 45 degrees Y, 0 degrees Z: Min. safety 6.06, Max. stress 45.4 MPa, Max. displacement 10.4 mm
• 30 degrees X, 0 degrees Y, 0 degrees Z: Min. safety 9.56, Max. stress 28.8 MPa, Max. displacement 1.74 mm
• 30 degrees X, 45 degrees Y, 0 degrees Z: Min. safety 7.20, Max. stress 38.2, Max. displacement 8.96 mm
• 100 degrees X, 0 degrees Y, 0 degrees Z: Min. safety 6.10, Max. stress 45.1, Max. displacement 2.32 mm
• 100 degrees X, 45 degrees Y, 0 degrees Z: Min. safety 7.23, Max. stress 38.0 MPa, Max. displacement 8.05 mm

As you can see, all of these values result in acceptable values.

In this chapter, I will give 2 examples of different ways that the SIMPLAE can be used in real life: as a single family temporary shelter, and as a disaster-relief base of operations.

One potential real-life use of the SIMPLAE is as a temporary shelter for people without homes. This could be due to a variety of reasons, such as natural disasters, war, or even just camping for leisure. A single SIMPLAE unit is designed to support one family (~4 people) at the most, but larger families might need to attach another unit.

The 1st image shows a bird's-eye view of the exterior of the shelter. The 2nd image shows the interior as well. The model will be explored in further depth below, as there are many details not visible in this view.

Inside the single family temporary shelter, there are two private sleeping areas, partitioned using curtains. The rest of the SIMPLAE is dedicated to food, storage, and recreation. There are also two batteries on the central pole, linked up to the solar panels. Although this model might seem sparse, this is only a baseplate with all the necessary items for living, and further decoration can depend on the inhabitants.

Note the window to the outside on the left. It is not very visible in this image, but the image I used for the background is from the aftermath of an earthquake in Japan, which is a scenario where this setup might be used.

From this perspective, the door to exit the SIMPLAE is behind the camera.

Another potential use of the SIMPLAE is to give disaster relief workers a place to work out of, so they can monitor the situation and find and help rescues faster. In this CAD, I have modeled what this might look like in real life.

The 1st image shows the exterior, bird's-eye view of the base. The 2nd image shows the interior as well. This is only to give an overview, and the model will be explored in further depth below, as there are many details not visible in this view. The legend corresponding to the images is:

1. Washroom + Water Treatment
2. Medical Room
3. Common Room
4. Dock
5. Work Room
6. Break Room
7. Solar Panels
8. Ropes, to tie the SIMPLAE together

The doors are difficult to see in these images, so I also drew a red door on all the doors.

Here are some things to note about this design:

• The base is made in a triangular design. This is to ensure stability, so that the base will not easily tip. This also minimizes the surface area exposed to the outside, decreasing the chance of punctures or getting stuck on something.
• The medical room is directly next to the dock, for faster access. For the same reason, the bathroom is also right next to the medical room.
• Every room has at least 2 exits, in case of emergencies. If all main exits are blocked, the windows are also large enough to escape from.
• There are always four ropes connecting the rooms together, for redundancy.
• The 1st tent (the washroom) is split into 3 different "rooms", using curtains. This allows for 2 washrooms and a storage room within a single SIMPLAE unit.
• Though not very visible in this image, there are curtains across the entrance to the bathrooms, for privacy.
• This base is NOT meant to accommodate rescues from natural disasters. It is primarily intended for workers to monitor and coordinate rescue efforts, and it can only temporarily hold rescues until suitable habitation can be found (the individual SIMPLAEs, as previously shown).
• To that effect, the medical room is not intended as a full hospital, as it lacks many necessities. Instead, it can only give basic treatments, and temporarily hold patients until better care is found.
• This build is based off of the conditions in the 2023 Beijing-Tianjin-Hebei Heavy rain flooding. For this reason, the solar panels are angled towards the south-east and south-west, to get the most sunlight. This also means the solar panels will generate power at all times of day. For different locations, simply rotate the base in different directions.

A note:

Although I chose to arrange 6 SIMPLAE units in this triangular shape, that's not all the SIMPLAE can do. From simple clusters of 2 to 3 units for larger families, all the way up to sprawling complexes with dozens to hundreds of units, there are endless possibilities! I simply chose this arrangement because I feel it strikes a nice balance between practicality and possibility.

Each washroom is equipped with a sink, a shower, and an accessible, low water toilet. Curtains block off all entrances, for privacy during use. The storage is accessible from the back of the washroom.

From this perspective, the common room is to the back, and the medical room is to the left.

The medical room has 2 beds for patients, both enclosed in curtains for privacy. It also has two chairs, for patients who are waiting, and also for checkups. There is also a table with food and water, for easier access.

From this perspective, the bathroom is to the right, the dock is to the left, and the common room is to the back.

The common room is the unit which has the most connections. This reduces the connections in other units, meaning the other units can fit more items that they need. The common room can also be used for relaxation, and to hold people temporarily while they wait for accommodation. It can also double as a secondary work room, if needed.

From this perspective, the medical room is to the front, the work room is to the left, and the break room is to the far left. The bathroom is to the right, and an exit is to the back. Note how the bathroom is curtained off for privacy.

The dock is used to receive and store watercraft, which are essential for rescue efforts. The dock can also hold people temporarily while they wait for accommodation. The dock can also be used to get fresh air, and to improve mental health. In the case of emergency, the dock could potentially be used for helicopter landing, although this is not recommended.

From this perspective, the medical room is to the left, and the work room is to the front.

The work room is the most important room in the base of operations, where workers will monitor and coordinate rescue efforts. The work room has 3 computer stations, and a TV, for easier monitoring.

From this perspective, the dock is to the right, and the common room is to the back.

The break room is for the workers to relax and rest in their off time. There is a private sleeping area, in case that is necessary. This is also where workers will eat lunch. This room can double as a tertiary work room, if needed.

From this perspective, an exit is to the left, and the common room is to the back.

In this chapter, I will analyze and reflect upon this CAD as well as the design process, and give you some final thoughts. For all of the following calculations, I am using data from the 2023 Beijing-Tianjin-Hebei Heavy rain flooding.

The primary method of generating power in the SIMPALE is solar panels, as shown in the previous chapter. But how much energy can the SIMPLAE handle from the solar panels alone?

According to University of Michigan, commercial solar panels have an average efficiency of around 20%. According to a research group, the average solar irradiance (the amount of sunlight a place receives) in Beijing is approximately 1241 kWhm^-2. The total solar panel surface area on a single SIMPLAE unit is 1955200 mm^2. Thus, the math works out to approximately 469.25 watts per unit.

But how much energy does the SIMPLAE use? According to Mega Plus Synergy, a single LED bulb at 1100 lumens draws 17 watts. Each SIMPLAE comes with 6 lights, so the lights use 102 watts. There is also a digital display on the battery of each SIMPLAE, so we will increase that to 119 watts.

Assuming no other use, this means that over 300 watts are going unused, which is much more than enough to be safe. However, there are many activities which might require more electricity, which is why I have created the chart in the 1st image.

Image transcription:

Power generation: Solar 469.25 W

Power consumption: Phone charger 5 W, Laptop charger 60 W, Computer 60 W, Television 100 W, Lights 119 W, Kettle 1300 W, Heater 1500 W, Stove 2000 W, Shower heater 7000W!!!!

As you can see, under ordinary use, the power generation is more than enough -- the 4 solar panels can handle several phone and laptop chargers. However, many first-world conveniences we are used to, such as kettles and hot showers, take too much for the solar panels alone to support. I was especially surprised by the amount of power that shower heaters need. I should take shorter showers.

Luckily, when power is desperately needed (such as for heaters in cold environments), the SIMPLAE comes equipped with a fully charged battery. This battery can be recharged using solar panels, other power sources, or even just replaced with a new battery. That is also how the SIMPLAE provides power through the night, or when the sun is blocked.

So to summarize, how did the SIMPLAE do on power? Here are my thoughts:

• For its most important use case (disaster relief), the SIMPLAE generally provides more than enough power, and surpasses its goal.
• The power generation is also sufficient for most other use-cases, such as research and exploration.
• However, the power has one glaring flaw: cold environments! Especially in places where it can go for months without sunlight, such as the arctic, the solar panels struggle to reach the power needed for most heaters. Even with proper insulation meaning minimal heat loss, the majority of the SIMPLAE's power consumption will be taken up by heating.
• In such cases, alternative power generation will need to be used, or extra batteries will need to be shipped. Alternative methods for power are usually sparse in cold environments, meaning batteries will likely be used. This is regrettable, as it reduces the longevity of the SIMPLAE, and increases the environmental footprint.

The only source of water in the SIMPLAE is the rainwater catcher, installed on the exterior. The efficacy of this source will vary widely, depending on the amount of rain. In Beijing, the amount of rainfall is likely sufficient to sustain ~4 people, since there is a moderate to heavy amount of rain in July. It is worth noting again that rainwater is generally NOT safe to drink, and it always needs to be filtered first to be safe.

Furthermore, drinking is not the only usage for water. In the first image is a list of how much water different activities require.

Image transcription:

Water generation per day: Rainwater Varies

Water consumption per day: Plant (Areca Palm) 21 mL, Plant (Average houseplant) 321 mL, Drinking water 3.5 L (per person), Toilet (low flow) 6 L per flush, Drinking water (for 4 people) 14 L, Toilet 26 L per flush, Shower (8 minutes) 65 L!!!

Once again, I need to take shorter showers.... So to summarize, how did the SIMPLAE do on water? Here are my thoughts:

• The only consistent source of water across the world is rain, and even that varies.
• The SIMPLAE makes use of rain, so it does well in this regard.
• Other sources of water, such as wells and rivers, will vary depending on the location.
• In most scenarios, the rainwater catcher is not intended as the main source of water: it is simply a supplement to other sources. However, it is still extremely valuable to have in case of emergencies.
• The SIMPLAE does not have a method to dispose of/treat waste water. However, given the constraints, this is expected and reasonable. Instead, waste water must be collected and saved for future treatment.
• You might have noticed in the previous CAD model that there is no dedicated storage for gray water. It is expected that gray water will be reused for safe tasks, such as toilet water or feeding plants. This will lower water consumption, and lower the environmental impact.
• As for plants, the Areca Palm was chosen, due to its oxygen purification and low water usage, according to a NASA study. This low water usage is apparent in the above chart.

The SIMPLAE was initially designed with safety in mind, in order to reduce human labour in extreme environments. But how did it really do? Here are my thoughts:

• Being able to inflate and expand without human intervention is extremely valuable, especially in unsafe environments. It also reduces the difficulty in construction, and the possibility of error, as most people do not know how to construct their own habitation. The SIMPLAE excels in this regard.
• However, some of the additional, optional parts might be difficult for humans to install. Notably, the solar panels are high up and difficult to reach. But, if the environment is truly making it dangerous to install solar panels on top of the unit, alternative methods can be used, such as inflating another "dock" with solar panels on the floor.
• Another difficult to install aspect would be the "bridges" connecting the units together. However, due to the redundancy in the 4 ropes connecting the units, the danger is minimized.
• The windows of the SIMPLAE are deliberately made quite large and low, and fully openable. This serves as an alternate escape method, in case all exits are blocked. However, this can still be difficult and dangerous for immobile, young, or elderly persons. This issue can be minimized by ensuring every SIMPLAE unit has at least two accessible exits in larger structures.
• As evidenced in Chapter 3, the structural stability of the SIMPLAE is more than satisfactory. Furthermore, the materials used in construction were deliberately selected for safety: for example, PVC is highly puncture resistant and highly abrasion resistant, minimizing the danger of deflation.
• In the case that deflation does occur, the "floor" of the SIMPLAE is equipped with 2 separate gas chambers (as per the Canadian maritime safety requirements) meaning a single one deflating will not lead to sinking. If a chamber is punctured, the unit can be evacuated before any further punctures.
• In summary, the SIMPALE excels in safety.

Another large focus for the design was the mental health of the inhabitants. Because people would likely need to live in a SIMPLAE unit for months at a time, it is important to make sure it is comfortable.

Privacy was a key factor in the design, since that can be important for people's comfort. All the windows have fully opaque curtains which can be drawn, and curtains can be hung on the mechanism, for added privacy. In a similar vein, I also ensured that there were many, large windows, such that people can get fresh air and sunlight if they wish. The colour of the interior was also specifically selected, to be darker and less alarming than the exterior. This should help inhabitants calm down and relax, in what would otherwise be stressful situations. Plants and other decorations can also be used to improve mental health.

So, how did the SIMPLAE do on mental health? Here are my thoughts:

• Given the design constraints, there are not many steps that can be taken for comfort. The SIMPLAE will always inherently lack the modern comforts we are used to, such as solid walls for privacy and hot baths to relax. However, given these restrictions, the SIMPLAE does an excellent job at maintaining a level of dignity and mental health for the inhabitants, in these sparse conditions.

Sustainability is one of the areas which I sadly had to neglect for sake of other factors. Although I really would have liked to further reduce the environmental impact of the SIMPLAE, I deemed it more important to focus on the safety and protection of the inhabitants. For this reason, PVC is used in parts of the build, despite it being the most environmentally damaging plastic. Although I really would have liked to use a different material, PVC is the most suitable material I could find for preventing potential penetration and capsizing the SIMPLAE's inhabitants.

However, that doesn't mean the SIMPLAE doesn't do anything for sustainability. Here's my overall analysis on this:

• Although PVC is extremely environmentally damaging, it also has one of the most advanced recycling processes. This means that, while environmental contamination is inevitable, continued contamination can be prevented by recycling old SIMPLAE units.
• Speaking of which, the umbrella mechanism is also fully recyclable, since it is made out of aluminum. This means that the SIMPLAE is entirely, 100% recyclable!
• So although the SIMPLAE might spread contaminants in the short-run, it is fully ecologically green in the long-run.

Food

• The SIMPLAE makes no effort to provide a food source for the inhabitants, as that would be extremely costly and difficult given the constraints. Alternative sources or supplies will need to be used instead.
• Theoretically, a SIMPLAE unit could be used to grow food. However, this would again be costly and difficult, and likely not worth the effort.

Air

• Once again, there are not many ways to control the air quality, given the design constraints. In a situation where the air is dangerous to breathe, an airtight exterior can be draped over the tent. Otherwise, there is suitable ventilation through the windows for safe breathing.
• Plants (especially the Areca Palm plant) should be used to improve air quality and remove toxic gasses.

Looking back at the work I've put into this project, I can confidently say that I have grown and learned a lot. Not only have I become intimately familiar with Autodesk Fusion, which is a software I had never used before, but I also learned about a variety of useful techniques such as analyses and simulations. Furthermore, my knowledge about the world and about different environments has increases significantly, as I've learned so much about what it takes to survive in different conditions. I've also learned so much about different types of material, how we manage our power and water, and, of course... that I should stop showering for so long!

Thank you so much for reading up to this point, and good luck on your CADing adventures! Feel free to post any questions, comments, or concerns in the comment section below!

Models used:

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