The HOUSE module forms the element mass and stiffness matrices of all elements. The name of HOUSE module is HOUSEFS for fast-solver code option and HOUSEFSA for Option AA.

The FEA model may include only the structure, and also the near-field soil, especially of irregular soil zones are present. For the Option AA, the HOUSEFSA input includes uses directly the ANSYS model matrix files, as described in the “ACS SASSIANSYS Integration Capability” User Manual.

For the baseline code with the standard solver, the structure and basement stiffness and mass matrices are stored in separate files.

The random field decomposition for incoherent motions is performed in this module as well.

The HOUSE results for incoherent SSI or nonuniform/multiple support excitation option are stored in another file that is later used by ANALYS. If the user desires to check the accuracy of the coherence kernel decomposition, HOUSE can output the incoherent mode contributions. If many incoherent stochastic simulations are executed, then, a set of files will be produced. Each of these include the incoherent motion information for all three directions in space, X, Y and Z.

The HOUSE module incorporates an optimizer for the node numbering. This node numbering optimizer is highly effective for large-size SSI models with significant embedment. The Option AA HOUSEFSA module uses automatically the optimizer. We always recommend use of the node numbering optimizer for larger size embedded SSI models.

After running the module, a new HOUSE input file be containing the new optimized SSI model, accompanied with another file that contains the original nodes and the corresponding new node numbers after optimization is applied.