The Earthquake Engineering Online Archive NISEE e-Library
QUAD-4: a computer program for evaluating the seismic response of soil structures by variable damping finite element procedures
Idriss, I. M.; Lysmer, John; Hwang, Richard N.; Seed, H. Bolton
UCB/EERC-73/16, Earthquake Engineering Research Center, University of California, Berkeley, 1973-07, 79 pages (480.2/I34/1973)
The analytical procedure that presents the use of a different damping ratio in each element of a finite element mesh is formulated. This procedure allows the incorporation of both stiffness and damping values that are strain-dependent for each element. The use of this variable damping finite element procedure in evaluating the response of soil deposits during earthquakes is described and a listing of the computer program used in the evaluations is presented.
Available online: http://nisee.berkeley.edu/documents/EERC/EERC-73-16.pdf (2 MB)