Page 159 - Finite Element Analysis with ANSYS Workbench

150 Chapter 8 Failure Analysis

figure is 3.3892. This means the critical bucking load of the bottle
is 166.24 N because the applied load is 49.05 N. In another word,
the bottle won’t buckle if the applied compressive load is less than
166.24 N.

This example highlights benefits of the finite element
method to provide information necessary for the design of
complicated model. The ANSYS software though the use of its
Workbench helps the analysis process to proceed with ease.

8.2 Fatigue and Life Prediction

8.2.1 Fundamentals

Fatigue is one of the common problems that causes
structural failure. The failure may occur even though the stress is
less than the yield or ultimate stress if the structure is under cyclic
loading. As shown in the figure, the cyclic stress varies up and
down with cycles, where  max is the maximum stress,  mim is the

minimum stress,  is the mean stress, and  is the alternating
a
m
stress.