ACS SASSI is a highly specialized soil-structure interaction (SSI) finite element analysis software. The software is a user-friendly finite element computer code on the MS Windows PC platforms for performing efficiently linear or nonlinear 3D dynamic soil-structure interaction (SSI) analyses for complex geometry foundations subjected to spatially varying incoherent motions or multiple support seismic excitations. ACS SASSI is a modern software coded using advanced features of VC++ and Fortran90+, languages, provides a set of totally new engineering capabilities for SSI analysis in comparison with the original SASSI developed by Professor J. Lysmer and co-workers at University of California at Berkeley.
The ACS SASSI software is a software in a continuous fast development. In addition to the computational speed improvements through a full parallelization of the code that makes it hundreds of times faster than the university SASSI code, ACS SASSI includes a totally new set soil-structure interaction analysis capabilities that extends the linearized SASSI methodology to nonlinear soil and structure and probabilistic soil-structure interaction problems including the effects of incoherent seismic wave fields and inclined soil layering geometries. The new added soil-structure interaction capabilities make ACS SASSI the most complete seismic soil-structure interaction analysis engineering tool for nuclear structure projects. The recent versions already included section-cut capabilities and powerful ACS SASSI-ANSYS integration capabilities. The ACS SASSI-ANSYS integration capability included in Options A-AA covers an area of great interest for practical applications. This capability provides an advanced two-step SSI approach that can include more refined finite element analysis structural models in the second step, including some local nonlinear material and/or nonlinear geometric effects in the structure or at foundation interface with the soil.
The ACS SASSI software allows analysis of soil-structure interaction models with up to 650,000 nodes or 2,500,000 degrees of freedom. The software can run simultaneously up to tens or hundreds of dynamic load cases for a small runtime increase. Thus, for flexible foundation impedance problems that requires a large number of unit amplitude harmonic loads, the software can run up to 500 separate load cases in a single run, depending on the size of the problem and the available RAM. Also, for seismic incoherent soil-structure interaction analysis problems, ACS SASSI can run up to 50 stochastic simulations including X, Y and Z components for each in a single soil-structure interaction analysis run, depending on the size of the problem and the available RAM.