DETERMINATION OF DYNAMIC RESPONSE OF STEEL SHELL USING PHOTO-MECHANICS AND FINITE ELEMENTMETHODS
用光力学和有限元法确定钢壳的动态响应

This paper presents a solution to the problem of three-dimensional dynamicdisplacement distributions on curved surface under impact loading utilizing photomechanics and finite element method.In-plane displacements (U', V) on the curved surface can be measured from the spectrum of far-field objective laser speckle by means of the pointwise filtering method. out-plane displacement w' of the shell surface can be obtained combining the Moire interferometry and above method.An impulse force was applied using a new type of electromagnetic forcing mechanism which gives a good repeatability. The relation of instantaneous loading and time which was set for the forcing boundary condition in the finite element calculation of displacement components was recorded experimentally.Two suitable external trigger mechanism were used to fire the Ruby-laser system at predetermined intervals.It is shown that the experimental results are in good agreement with those of finite element method. This mixed method is proved efficient.