SoilQuake.net

LS-DYNA

LS-DYNA is a finite element package developed by Livermore Software Technology Corporation. This numerical code have been employed to solve nonlinear problems using explicit and implicit time integration in industries such as the automotive, aerospace and construction industries.

The UCSD soil models UCSDSAND3BETA and UCSDCLAY have been integrated into LS-DYNA as user defined material models. These material models are capable of simulating the essential dynamic response characteristics of cohesionless and cohesive soils 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 LS-DYNA example. For additional information, please reference the user manual.

Step 1: Download and Installation

    1) If you do not have LS-DYNA installed, please visit http://www.lstc.com to obtain the analysis package.

    2) Download LS-DYNA_Example.rar (53 MB, updated 9/11/2017)

    3) Unzip all files in the LS-DYNA_example.rar to a desired location. The zip file includes the material models (lsdyna_ucsddemosoilmodels.exe), and an excel sheet interface (1D_Seismic_Site_Response_Example.xlsm).

    4) Please move lsdyna_ucsddemosoilmodels.exe (contained in the above Example file) to the main folder of the LS-DYNA installation folder.

    5) Update LS_DYNA_location.txt with the location of the LS-DYNA 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 LS-DYNA 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 LS-DYNA.

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


Model Performance

Below are some sample responses using the UCSD soil models. Click images to see full sized versions.


UCSDSAND3BETA - Saturated:
Soil Column in LS-DYNA
Excess Pore Pressure Time History
Shear Stress vs. Shear Strain
Shear Stress vs. Confinement


UCSDSAND3BETA - Dry:
Soil Column Model in LS_DYNA
Shear Stress vs. Shear Strain


UCSDCLAY:
Soil Column Model in LS-DYNA
Shear Stress vs. Shear Strain


Usage of UCSDSAND3BETA and UCSDCLAY

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