Dynamic Member Failure in Trusses by Pseudo-Force Method

Abstract

The paper presents a systematic technique based on “pseudo-force” concept to determine dynamic response of truss structures during sudden progressive member failure. Emphasis has been given to the dynamic nature of the member failure and effects of such dynamic member failure on the overall structural behaviour. Responses of two-dimensional cantilever truss and a three-dimensional, corner supported, double-layer grid truss structure were investigated during sudden failure of some compressive members. In the method the sudden reduction in the load carrying capacity of a member is represented by external forces applied suddenly at the end joints of the member. Results obtained delineate the dynamic effects of member failure on joint displacements and member forces/stresses. In the present study the method is established for linear analysis. However, the pseudo-force approach can be extended for non-linear analysis and to represent the member snap-through and dynamic jump due to inelastic member buckling/post buckling in a truss-type structure.