Zero stiffness method for fail-safe analysis

Abstract

One of the major engineering tasks is to evaluate the structural behavior when one of the components has failed. In such cases it is necessary to carry out fail-safe analysis to evaluate if the structure can be used safely in loading conditions. Thus, fail-safe analysis is a vital and important task to properly validate the mechanical structure. The implementation of the fail-safe analysis using the finite element method is usually done by eliminating the given component from the finite element model and carrying out the given analysis. But when due to finite element modeling issues such an approach cannot be carried out without causing singularities in the model, another approach should be used to perform the fail-safe analysis. One such method, presented in this paper, is the zero stiffness method, which applies near-zero stiffness to the structural component that is removed from the finite element model. The zero stiffness method is used by applying close to zero values to the material and element properties, and thus reducing the load that is in the given structural component.

Keywords

• fail-safe analysis
• zero stiffness
• finite element
• aerospace structures