Use of Visual Analysis

To model the Canadian National Tower, the use of Visual Analysis is required to define the foundations of the tower such as the weight loads, visual images of how the tower is affected from weight loads, and modifying certain members. For this week, a visual analysis problem was given to us to gain a better understanding of how to use Visual Analysis. The following picture is what we had to analyze :

After putting this Visual Analysis file into the program, a result/report view reported the problem was that "A negative stiffness diagonal  has been found at node: 022 Z-Translation Check your model for stability problems near this location." The solution to this problem was to adjust the nodes, add a few members, and make some points fixed and free.

The first revision was done by implementing a type of Pratt Truss because during the Bridge Design in Engineering Design Laboratory, it was found to be the strongest truss out of the main three of Howe, Pratt, and Warren. After making these modifications, the same problem was still occurring with negative stiffness diagonals. Some adjustments were applied to the vertical part of the bridge to eliminate these problems.

The result/report view was displayed correctly without any further problems. The left picture is the newly modified version and the right picture is the correctly displayed result view. 

Visual Analysis techniques were learned thanks to watching some tutorials and making several modifications to the assignment. It was difficult modifying some of the nodes and members because of the snap modes. It was fun messing around with the members to test how the bridge would bend and pushed to the ground. It was annoying constantly dealing with the problem of negative stiffness. 

The main challenge right now is finding the right 3D rendering program to make a 3D model of the CN Tower that would work along side with Visual Analysis. Right now we are still using Creo Parametric for the model.