NEHRP Clearinghouse

Title
Dynamic Stiffness Matrices for Homogeneous Viscoelastic Halfplanes.
File
PB279654.pdf
Author(s)
Dasgupta, G.; Chopra, A. K.
Source
National Science Foundation, Washington, D.C., November 1977, 125 p.
Identifying Number(s)
UCB/EERC-77/26
Abstract
Analytical expressions and numerical results are presented for the complex-valued, dynamic (frequency dependent), flexibility influence coefficients for a homogeneous, isotropic, linearly viscoelastic half space in plane strain or generalized plane stress. These influence coefficients, defined for uniformly spaced nodal points at the surface of the half space, are obtained from solutions of two boundary value problems, associated with harmonically time-varying stresses uniformly distributed between two adjacent nodal points. Numerical values for these coefficients are presented for a viscoelastic half space of constant hysteretic material. A method is developed to determine from these results the dynamic stiffness matrix, associated with the nodal points at the base of a surface supported structure, for the half space. The resulting dynamic stiffness matrix is shown to be superior compared to the one determined from an available procedure, which is based on solutions of displacement boundary value problems for the half space. (Portions of this document are not fully legible)
Keywords
Dynamic response; Ground motion; Computer programs; Earthquake engineering; Earthquakes; Soil structure interactions; Nuclear power plants; Earth movements; Stresses; Stiffness methods; Boundary value problems