Abaqus is a finite element package developed by Dassault Systèmes Simulia Corp. This analytical software is used to solve multiphysics problems which includes fluid, thermal and electrical.

The UCSD soil models UCSDSAND3BETA and UCSDCLAY have been integrated into Abaqus/Standard as user defined material models. These material models are capable of simulating the essential characteristics of sands and clays respectively. Additional references can be found here.

Example of 1D site response analysis which utilizes the demo versions of the soil models is provided below (for illustration purposes). For the 3D full version of the soil models, please contact Prof. Ahmed Elgamal (E-mail: elgamal AT ucsd DOT edu).

1D Seismic Site Response Example

Please follow the steps below to download, install, and run the Abaqus_Example. For additional information, please reference the user manual.

Step 1: Download and Installation

    1) If you do not have Abaqus installed, please visit to obtain the analysis package.

    2) Download Abaqus_Example.rar (10 MB, updated 8/31/2017)

    3) Unzip all files in the Abaqus_Example.rar to a desired location. The zip file includes the material models (standardU.dll), and an excel sheet interface (1D_Seismic_Site_Response_Example.xlsm).

    4) Please move standardU.dll (contained in the above Example file) to the userlib folder. (ex. "C:\SIMULIA\Abaqus\userlib"). If the path was changed, please move to the appropriate folder.

    5) Add usub_lib_dir="C:\SIMULIA\Abaqus\userlib" (same path as step 3) to abaqus_v6.env, which can be found in the site folder. (ex. C:\SIMULIA\Abaqus\6.14-2\SMA\site)

    6) Update Abaqus_location.txt with the location of the Abaqus installation.

Step 2: Run 1D_Seismic_Site_Response_Example

    1) Open 1D_Seismic_Site_Response_Example.xlsm. If prompted please enable macros. This Excel sheet makes use of macros to generate input files for Abaqus and run the analysis.

    2) Update the material and analysis parameters shown on the Excel sheet and then click "Create Input and Run" to start the analysis in Abaqus.

    3) Upon completion of the analysis click "View Results" to load the output.

Model Performance

Below are some sample responses using UCSDSAND3BETA for seismic analysis (no water). Click images to see full sized versions.

Soil Model in Abaqus
Shear Stress vs. Shear Strain


For information on how to use the soil models UCSDSAND3BETA and UCSDCLAY in Abaqus, please click here.