Description |
QUAD-4 is a 2D time domain solution to dynamic soil response incorporating independent damping in each element in the continuum and a transmitting base so that the half-space beneath a mesh can be modeled, and the need to assume a rigid foundation can be eliminated. The shear and compression wave velocities and the unit weight for the material underlying the mesh can be entered, and the response of the mesh on top of that half-space can be modeled. In addition, seismic coefficients are included for use in deformation analyses. The program also has a restart capability. The acceleration, velocity, and displacement are stored for the restart so that the program continues as if no interruption had occurred. This feature is useful for changing material properties during the shaking event. It incorporates a new method for the formulation of damping matrices which results in a significant reduction of the damping of higher frequencies commonly associated with the use of a Rayleigh damping formulation. |