SISAME Modeling Overview

SISAME (Structural Impact Simulation And Model Extraction) is a unique and powerful system for vehicle crash modeling and safety design. The ObjexxSISAME Suite provides a sophisticated approach to the generation and simulation of efficient, accurate dynamic structural impact models. SISAME can perform one-step structural design optimization to best achieve a desired crash performance subject to structural and cost constraints. ObjexxSISAME complements the detailed analysis abilities of finite element modeling with a direct design capability.

ObjexxSISAME extracts optimal lumped-parameter models that best reproduce observed or desired crash behavior. Models have a set of rigid mass elements and massless load-paths. SISAME models of modest granularity have a high degree of expressive power and can accurately characterize crash responses.

A range of static and dynamic load-path types is available. SISAME identifies static and dynamic load-path parameters during an extraction run and can then be used to simulate the model under different conditions. SISAME can also identify optimal mass weights via inertial--external force matching.

Applications for SISAME modeling include:

• Optimal structure redesign to meet a safety performance standard subject to structural and cost constraints.
• Predictive simulation of crashes at other speeds or impacting other vehicles.
• Tuning finite element models to improve conformance to measured test data.
• Distillation of finite element models for efficient simulation of a matrix of events.

The SISAME technology was originally developed by Objexx Engineering's principal for the U.S. Dept. of Transportation, National Highway Traffic Safety Administration (NHTSA) and is in use at a number of sites around the world.

Objexx offers the ObjexxSISAME Suite and provides SISAME training, modeling, and customization services to clients in the automotive safety community.

Resources

• NHTSA SISAME website: http://www-nrd.nhtsa.dot.gov/software/sisame/
• Mentzer, S.G. et al (1992). The SISAME Methodology for Extraction of Optimal Structural Crash Models. SAE Report No. 920358.