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