Introduction to OpenSees

Context for Simulation in Earthquake Engineering

• Research and practice is moving towards Performance-Based Seismic Engineering, which depends on high-fidelity models and simulation to assess performance.
• Simulation models capture knowledge from tests to leverage investment in limited experimentation.
• Community-based, open-source software for simulation promotes innovation in research and advanced applications for practice.
• NEES infrastructure is supporting OpenSees to provide simulation capability and integration with NEESit services for NEES research.

What is OpenSees?

• A software framework for simulation applications in earthquake engineering using finite element methods. OpenSees is not a code.
• A communication mechanism for exchanging and building upon research accomplishments.
• As open-source software, it has the potential for a community code for earthquake engineering.

Simulation Framework

Computation

Algorithms

Solvers

Parallel/distributed computing

Information Technology

Software framework

Databases

Visualization

Internet/grid computation

Models

Simulation models

Performance models

Limit state models

Material

component

system models

OpenSees Approach to Simulation

Basic approach

Modular software design for implementing and integrating modeling, numerical methods, and IT for scalable, robust simulation

Focus on capabilities needed for performance-based engineering

Programmable interfaces

Most users

a “code” for nonlinear analysis

Fully scriptable.

Generally

a software framework for developing simulation applications