Dynamic Snap-through Buckling of Truss-type Structures

Space trusses under certain conditions may be prone to snapthrough buckling. The sudden reduction of the load carrying capacity of a single critical compression member, or a group of compression members, may lead to the snap-through buckling of the compression chord of the structure. This temporary loss of equilibrium due to snap-through normally results in a dynamic force being applied to each node associated with the snap-through. In this paper a methodology based on energy methods is presented to determine the dynamic snap-through response of truss structures. Member failure is taken into consideration by carefully following the buckling load-displacement response of the member. It is assumed that the structure is subjected only to static gravitational loading. A one degree of freedom, simple three bar truss, is used to describe the approach. Finally, this method has been used to perform the snap-through buckling analysis of two double layer grid structure providing a load-displacement behaviour from each structure variation to that obtained from a conventional static analysis.