> > Buckling Analysis Problems

Buckling Analysis Problems
This chapter contains a buckling analysis problem and Structure's results. In a buckling analysis, Structure calculates buckling load factors and mode shapes that determine the critical magnitudes of load at which a 3D structure will buckle. Structure also automatically calculates all predefined measures. This list of measures differs based on the analysis type.
This chapter contains the following models:
mvsb002: Buckling Analysis of Composite Lay-up
mvsb002: Buckling Analysis of Composite Lay-up
 Analysis Type: Buckling Transversely Isotropic Model Type: 3D Comparison: MSC/NASTRAN Reference: Jones, R.M., Mechanics of Composite Material, Hemisphere Publishing Corp., 1975, pp 260-261. Description: A four-layered transversely isotropic square plate is simply-supported and subjected to an in-plane load. Determine the buckling load factor.
Specifications
 Element Type: shell Units: IPS Dimensions: length: 10width: 10thickness: 0.1 Ply lay-up: 0/90/90/0 Thickness of each ply: 0.025 Shell Properties: Extensional Stiffness A11=1.54e06 A12=18,779 A16=0 A16=0 A26=0 A66=37,500 Extensionalâ€“Bending Coupling Stiffness B11=0 B12=0 B16=0 B22=0 B26=0 B66=0 Bending Stiffness D11=2,198.75 D12=15.6495 D16=0 D22=367.762 D26=0 D66=31.25 Transverse Shear Stiffnesses A55=32,553 A45=0 A44=17,940 Material Properties: Mass Density: 0.002 Cost Per Unit Mass: 0 Young's Moduli E1=3e7 E2=750,000 E3=750,000 Poisson's Ratio Nu21=0.25 Nu31=0.25 Nu32=0 Shear Moduli G21=375,000 G31=375,000 G32=E2/[2*(1+Nu32)] Coefficients of Thermal Expansion a1=0 a2=0 a3=0 Constraints: Fixed in out of plane (z-direction) translation along all outer edges (AB, BC, CD, and DA).Fixed in translation in all directions at point DFixed in x & z-direction translation at point A Loads: In-plane force/unit length load=1:in +x-direction along edge DAin -x-direction along edge BC
Comparison of Results Data
 Theory Structure % Difference Buckling Load Factor 268.73 267 0.6% Convergence %: 0.0 % on buckling load factor. Max P: 6 No. Equations: 455