New Parts for Physical Model

For the physical model, we have constructed the hexagonal base and the four caissons which is the primary foundation for the CN Tower. We went to the wood shop and utilized their tools to make the right parts for the tower.

For this week's assignment, we had to mainly focus on making the parts of the physical model and fixing up the Visual Analysis Model. From the previous post of our blog, Island was in charge of fixing the Visual Analysis Model so that it would not fall apart anymore while applying loads to it. Yuan is currently fixing up the Final report for grading in week 10, Michael updates the blog by posting about current progression, and Steven works on the physical model of the tower.

Here are some pictures of the parts we made at the wood shop :

We needed to sand down the sides of the 360 restaurant to make the slants of the part.

This is a picture of the primary parts of the foundation for the tower. There's a hexagonal base below the tower and above the 4 caissons for a strong foundation.

A picture of how the foundation will look like under the tower when all put together.

The main difficulty this week was having the correct visual analysis model because of importing different parts from Creo Parametric. The only solution was to make the tower as a whole and it was correctly shown in the result view. Also, since we don't have considerable experience with the wood shop, some measurements of the parts were inaccurate. We did our best to make the precise cuts that corresponded with the scaled down measurements of the tower. 

Update On Visual Analysis

Last week, we discussed that there were problems involving importing the revolving restaurant portion of the CN Tower to Visual Analysis. There was also another problem that occurred when going onto result view. We realized that importing an assembly would cause the tower to fall apart because an assembly is just a bunch of parts connected together. We tried to fix this by changing deleting nodes and changing around members, however that proved to be tedious and inefficient. Examples of what we tried to do can be seen in figure 1 and 2.

figure 1: The circled nodes were deleted and replace with just one node.

Figure 2: The nodes were replace and a new member was made to represent connectivity between parts

We decided to create a new 3D CAD model, specifically made to import to Visual Analysis. This time the whole CN Tower would be made into one part, meaning no assembly. This way there would be no parts falling when the model is imported into Visual Analysis. The new part consisted of a new, more simplified version of the revolving restaurant, as shown in figure 3. 

Figure 3: New revolving resturant. 

It was successfully imported to Visual Analysis with surprising no problems at all! The new revolving restaurant did not affect the stiffness matrix of the tower, and no parts fell apart, as the whole CAD model was just one part. Figure 4 shows that the tower functions properly in Visual Analysis, and all the parts of the CN Tower moving as one. 

Figure 4: Result view of new imported CN Tower CAD model

Load analysis will be under way! We predict to finish sometimes this week. 

Physical Model Progress

For this week's goal in terms of the Physical Model of the CN Tower was to construct the pod , the revolving restaurant. Since the wood materials are not thick enough to make the whole pod, we cut out two circular pieces from the wood.

Using the extra piece of wood we had, the wood material of the revolving restaurant was cut out like this. 

These two pieces will then be glued together in order to make the revolving restaurant. However, we still need to make a bigger hole of these circular pieces so it can fit with the shaft of the tower. The difficult process will be making the restaurant actually revolve, which means that we will have to lathe the shaft. So far, the physical model looks like the following : 

Update on Visual Analysis

This week was focused on finding the error that occurred when importing the 3D computer model into Visual Analysis. Finding the error in the whole 3D model proved to be impossible. Each part of the computer model was imported into Visual Analysis and examined one at a time. Once imported, the parts were pinned to the bottom to see if they were structurally sound.

We found out that the error only occurred with the top portion of the tower. The revolving restaurant and above displayed several errors in the result view.

Afterwards, each part that did work was assembled together one part at a time and imported to Visual Analysis to see if there was any problems that occurred with importing assemblies of the parts into Visual Analysis. The result view was displayed, even after all the whole assembly of the tower, with the exception of the top, imported.

However, one thing was realized once the result view displayed. Visual Analysis did not see the 3D model as one part, except several different parts.

As shown in this picture, one of the wings falls off in the result view.

Draft for Final Proposal

https://docs.google.com/file/d/0ByKCbu-_5kaBMUtvN29tZ1dnYWM/view

To view the PDF file of our draft of the Final Proposal, look at the above link.

The remaining work we will be doing is focusing on making the physical model and analyzing the Visual Analysis model of the tower.

Wings Constructed !

After Engineering Design Laboratory class, we went to cut out our wings from the piece of wood with the drawings. The pictures above is a good idea of how the CN Tower will look like with the constructed wings. The next thing we will work on for the tower is the core and the pod. 

Visual Analysis Progress

After making the 3d model in Creo Parametric , we were able to save the model file as a DXF file which could be imported into Visual Analysis. Since the visual analysis programs provided were educational/student versions, we needed to download the 30 days free trial version that would be able to important DXF files. 

Importing the Creo DFX file into VA

After importing the DXF file into the Visual Analysis Free Trial program, nodes were selected to be either pinned, free, or fixed from the modifying tab. 

Core caisson of the tower

The circular motion symbol means that the nodes are fixed, meaning that it would be extremely difficult to move in terms of rotating and translating. All four of the caissons' nodes were fixed since they are the foundation of the tower which cannot move at all.

Concrete base with other caissons

The circle symbol means that the nodes are pinned, meaning that it can't translate but it has the ability to rotate. We made the concrete hexagonal base to be pinned on all nodes because it's not deep enough into the ground level and it could still rotate. 

The goal was to learn how to use the Visual Analysis program and to be able to import our Creo Parametric file into the program. With a little bit of guidance, we were finally able to do so. From there on after watching Visual analysis tutorials, we were able to fix the nodes to be pinned, free, and fixed. 

Now we can mess around with the program a little bit to make a better analysis model of the CN Tower. 

Ultimately, we're aiming for a result view of the tower's gravity loading and air resistance. 

(We're still working on that part)

Making Blueprints for the Wings of the CN Tower

The goals for this week was to make the wings of the CN Tower, which is the hardest part to make because of the wing's curve/bulge. The challenges for making these wings was making the radius part of the CN Tower's wings.

Setting the radius of the Wings

After scaling down the measurements from the actual CN Tower, we found the radius to be about 8-9 feet. So we used a 8-9 ethernet cable to draw the wings by stretching it out and moving it in a circular motion on the piece of wood where the wings were to be constructed. Stretching out the ethernet cable and moving it in circular motion was my role, Michael.

Making Measurements of the Wings

We were able to draw an accurate curve of the CN Tower, and put it up against the shaft to make sure it looked correct. At this point, we had only drawn one wing on one side of the wood. The wing's peak is .17 inches and the base is 1.75 inches. Drawing the part of the wing was Steven's role.

Making a Wing from Paper

Instead of using the ethernet cable to continually draw the other wings, we found a easier method which was to just make a wing out of paper and start tracing three wings on the wood which was Yuan's role.

Starting to trace the wings for the wood

Some of the drawing may be inaccurate due to inaccurate tracing. The other side of the wood's drawings may also not correlate with the current side being worked on. The solution to this was to use the paper as a straightedge and fold it on both sides to see if the wings can correlate with each other.

Completed Drawings of the bridge

These are the 3 completed drawings of the wings for the CN Tower. We tried to use a small handsaw in order to cut the wings out but it was proved to be difficult so going to the wood shop will be a better method to make precise cuts. If we used a regular jigsaw, the cuts could be inaccurate, especially if cutting the radius part of the wings. Island's working on the Visual Analysis model and still watching tutorials to learn more about the program.