Abstract
In this paper the numerical method on the structural crashworthiness is presented by using the Rigid Bodies-Spring Models (which is abbreviated as the RBSM).
In the design of engineering structures it is important to estimate the energy absorption characteristics by plastic deformation. But it is very difficult to simulate the crushing behaviour precisely by using the conventional numerical methods such as the finite element analysis because of the complexities of the phenomena. In the crushing behaviour of thin-walled steel structures plastic region is localized and the collapse mechanism is similar to the link mechanism which consists of rigid plates and plastic hinge lines. This behaviour is often idealized as rigid-plastic and the rigid-plastic analysis can be used approximately.
In case the collapse modes are known, the crushing behaviour of structures can be simulated by using the RBSM with much less number of degrees of freedom than the conventional finite element method, furthermore, the internal plastic work by the membrane shearing force, which can not be calculated accurately in the rigid-plastic analysis, can be taken into account generally.
In this paper the updated Lagrangian formulation for a flat rigid plate element with the moving local coordinate systems is presented and the crushing behaviour of some typical structural members is numerically simulated. The obtained results for the mean crushing load are compared with the experimental ones. All of the calculations are carried out as the static analysis where the inertial forces and the strain rate effect are neglected.
