RANDOM VIBRATION ANALYSIS METHOD IN DISPLACEMENT INPUT MODEL UNDER TRAVELING WAVE EARTHQUAKE EXCITATIONS
In traveling-wave excitation analysis,the free nodal absolute displacements are decomposed into pseudo-static and dynamic parts respectively in conventional pseudo excitation method(PEM) of random vibration,and the mass and stiffness matrices of free nodes must be obtained for constructing pseudo acceleration and displacement harmonic excitation,which is very time-consuming especially for solving problems with many degrees of freedom.A new PEM is presented here,in which the free nodal absolute displacements can be solved directly in displacement input model.As only coupled stiffness matrices between free and restrained nodes is needed for constructing pseudo excitation,it is more convenient to use in engineering than conventional PEM.The error of the calculation results of basement elements in adopting the displacement input modeldue to the different omitted damping terms is analyzed,and an effective method is presented to solve the problem.