User:Eml4500.f08.bottle.ranto/HW6

Electric Pylon Analysis
Our team was asked to conduct an analysis of a 91 bar, 60 m high electric pylon. The properties of the pylon are:

Material = 300 M Steel Height = 60 m Young's Modulus = 200 GPa Area = 4 cm2 Density = 7.8 g/cm3

MATLAB was implemented in solving for the displacements, stresses in each bar, the reaction forces, the eigenvectors, and periods of oscillation.

Code
The following MATLAB code was developed and run:

Results
The results array for the axial stress on each bar is: Stresses =

2.1562e+006 -1.3071e+006 1.3468e+006 1.2911e+006 -7.0304e+005 -4.7596e+006 -2.465e+006 1.4236e+006 3.8538e+006 -5.7655e+006 -37882      1755.6  3.8655e+006 2.9395e+006 -3.6988e+006 -5.7661e+006 3.5896e+005 5.242e+006 1.9797e+006 -3.7749e+006 -6.5159e+006 5.5784e+005 6.4388e+005 5.9656e+006 -8.1704e+005 -3.9616e+006 2.32e+006 -8.1307e+005 -5.7556e+006 -28474 -9.9353e+005 -15214 5.9216e+006 55813 -4.8717e+006 1.3915e+006 -3023.3 -5.7588e+006 -4.854e+006 1.3904e+006 -1.8831e+005 2.258e+006 -6.32e+005 -4.0102e+006 1.0133e-007 1.4647e-007 64147 2.7001e+005 2.7149e+005 -2.0778e+006 -4.4271e+006 -5.8777e+006 -7.3549e+006 -8.662e+006 -8.6957e+006 2.5807e-008 -6.1883e-008 -5.397e-008 9.7638e-008 -1.7704e+005 2.2069e+005 -1.9193e+005 1.9887e+005 2.1464e+006 -2.083e+006 2.2895e+006 -2.2643e+006 2.1035e+006 -2.1464e+006 1.4138e+006 -1.3772e+006 1.5835e+006 -3.6928e+006 -97393      -23690        31208  9.0479e+006 9.3927e-008 9.0317e+006 -2.3815e-007 9.0511e+006 -1.3175e+005 -2.9645e+005 1.7966e+006 4.4876e+006 6.6233e+006 7.7755e+006 -1.0741e-008 -2.4017e-008 -1.9214e-008 -1.0741e-008

The highest stresses occur at: MaxComp = -8.6957e+006 CompBar = 55

MaxTens = 9.0511e+006 TensBar = 81

The following is a plot of the deformed (solid black line) vs. undeformed (dashed blue line) pylon structure:

Notice that the bars in which the maximum stresses occur are labeled with arrows.

Effects of Eigenvectors
The lowest eigenvalues and their corresponding oscillation periods are:

lam =  132.16       2468.4       2940.3

T = 0.54654      0.12647      0.11587

Plots of the effects of the three lowest eigenvalues are shown below. The blue dashed line represents the undeformed structure while the solid black line represents the deformed structure.

Statically Determinant
The final step in this problem was to determine whether the structure can be solved using statics. Since there are only two fixed points and four bars for which reactions must be computed, it can be determined that this problem is statically indeterminate.