Homework, Quizzes, Simulation Examples — Structural Instabilities — Lesson 5

Simulation Examples

Several simulation examples are provided here. Each of them comes with a description file, video instruction, and Ansys simulation file. All the simulations are conducted using Ansys Mechanical. Download the student version of Ansys software here.

(1) Buckling and Post-Buckling Analysis of a Ring-Stiffened Cylinder

This global and local buckling simulation of a ring-stiffened cylinder is a typical application of nonlinear stabilization. Explore the simulation workflow and pay special attention to the analysis settings. Check the stabilization energy vs. strain energy. Is the stabilization energy small enough compared to strain energy? Download the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

(2) Wind Turbine Blade Buckling Analysis

A wind turbine blade is a long, hollow structural component made of a composite material. Due to its slender nature, it is important to conduct a buckling design test to prevent such failure in service. Check out this simulation of a wind turbine blade buckling analysis to get an idea of the simulation workflow. Download the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

(3) Delamination of a Stiffened Composite Panel Under a Compressive Load

Delamination is a common failure mode in a composite caused by the separation of different layers at the interfaces. This model captures the compression-induced delamination of a stiffened composite panel. The buckling behavior creates a tensile force between the panel and the stiffener and causes delamination. Download the zip file and extract the contents. Go through the Readme file. Follow along with the provided How To Video file.

Homework

(1) Buckling of a Column with Different Boundary Conditions

In this homework, you are asked to replicate column eigenvalue buckling analyses for four different boundary conditions. Obtain the buckling load of each case and compare it with the theoretical Euler buckling force below, in which E is Young's modulus, I is the smaller moment of inertia of the section, L is the column length. Use k as a parameter to adjust the column length based on its boundary conditions. Find the parameters in the model and calculate the theoretical forces. Do they agree with the simulation? If not, what is the error percentage?

(2) Buckling Analysis Using Different Approaches

You have learned various approaches to perform a buckling analysis: the eigenvalue buckling method, the nonlinear stabilization method and the arc-length method. Apply these methods on this simple clip geometry to solidify what you have learned. Answer the questions below:

1. What are the differences between these methods?
2. What is the limitation of the eigenvalue buckling method?