Analysis Of Dynamic Response For Structure Subjected To Impulsive Loads

When supporting strongly dynamic loads, such as explosive loads and impulsive loads, the structures will show different mechanics characters from standing quasi-static loads. The deformation of the structure changes very fast as the loads change with time. The effect of the inertia force can't be ignored. The dynamic response for the structure, sustaining impulsive load, has been analyzed according to the following three aspects in the paper.1. The dynamic plastic response of the simple-supported beam considering of the finite deformation under arbitrary impulsive load. The dynamic plastic response for a pinned rigid plastic beam subjected to an arbitrary impulsive distributed load was investigated. The effect of strain hardening and strain rate sensitivity was ignored. The yielding curve was assumed to be rectangular. The whole dynamic response process was classified as four stages, in which the first stage and the fourth one are single plastic hinge mode, and the second and the third stage are two plastic hinges mode. A closed form for the velocity and deformation of the beam was obtained.2. The dynamic response for the damaged structural components. A computational model for the damage evolution of engineering materials under dynamic loading was analyzed. Two models for dynamic damage evolution of materials in general anisotropic damage state were presented; the first one was based on power function of the effective equivalent stress and the second on the damage strain energy release rate . The dynamic response of damaged structural components have been studied numerically .3. The numerical simulation of pre-stress reinforced concrete u-shaped beam impacted by vehicle. The project of Dengzhou bridge using pre-stressreinforced concrete u-shaped beam structure was considered, using finite element analysis software ANSYS/LS-DYNA to make numerical simulation. A predigested car model and a reasonable bridge model were presented after the bridge structures and the colliding characters were analyzed. The stress and the displacement of the concrete, bar, pre-stress bar changing with time were presented. The stress of the whole bridge at the time of the contact and the deformation of the whole bridge at the end of the contact are obtained.