User:Eml4500.f08.ateam.carr/HW7

Electric Pylon as a frame
The electric pylon structure from before is now analyzed as a frame. The following procedures are to be completed:


 * 1) Update Matlab code to accommodate frame elements
 * 2) Plot the undeformed and deformed structure
 * 3) Identify the frame element(s) with the highest nodal bending moment and shear force
 * 4) Is the frame model statically determinate?
 * 5) Compare the reactions obtained from the truss model to those from the frame model
 * 6) Find the lowest 3 eigenpairs
 * 7) Plot the eigenvectors

Recall the properties of the pylon:

Young's Modulus: 200 GPa

Moment of inertia: 1.33 x 10-8m4

Cross-sectional area: 4 x 10-4m2

Additional Code Required
Length.m ReduceM.m ReduceS.m PlaneTrussElement.m NodalSoln.m PlaneTrussResults.m

PlaneFrameResults.m

2) Plot of Undeformed and Deformed Truss and Frame Structures


The red represents the Pylon as a frame approximation while the cyan is representative of the truss modeling.

Code output
Per the Matlab output:

max_moment = 6.2872 max_momentele = 81 max_shear = 5.4826 max_shearele = 81

The highest moment is 6.29 N-m and occurs in element 81. The highest shear stress (transverse) is 5.48Pa and also occurs in element 81.

4) Statically determinate?
This problem is not statically determinate. The two-force member assumption does not hold and therefore there are more unknowns than available equations.

6) Lowest Theee Eigenpairs
Per the Matlab output, the lowest three eigenpairs are:

lam = 132.86      2471.2       2942.6

7) Plot of the Three Corresponding Eigenvectors