The Open System for Earthquake Engineering Simulation (OpenSees) is a software framework for simulating the seismic response of structural and geotechnical systems. OpenSees has been developed as the computational platform for research in performance-based earthquake engineering at the Pacific Earthquake Engineering Research Center.


OpenSees has advanced capabilities for modeling and analyzing the nonlinear response of systems using a wide range of material models, elements, and solution algorithms. The software is designed for parallel computing to allow scalable simulations on high-end computers or for parameter studies.

OpenSees providing beam-column elements and continuum elements for structural and geotechnical models. A wide range of uniaxial materials and section models are available for beam-columns.

Nonlinear analysis requires a wide range of algorithms and solution methods. OpenSees provides nonlinear static and dynamic methods, equation solvers, and methods for handling constraints.

Development Process

OpenSees is open-source. This website provides information about the software architecture, access to the source code, and the development process. The open-source movement allows earthquake engineering researchers and users to build upon each others accomplishments using OpenSees as community-based software.

Getting Started

The best way to get started is to download the software and run an example.

Development Team

The OpenSees development team includes the following individuals who have made major contributions. Many other individuals have contributed modules to OpenSees.

University of California, Berkeley

Oregon State University

University of California, San Diego

University of Washington

Stanford University