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Simulation-based system reliability for design

The need to shift to system-level considerations in structural engineering is well documented, as are the inherent challenges [1-6]. With the advent of powerful computers, system-level random simulations are becoming faster. We propose here a ‘direct-simulation’ based approach to obtain second-moment estimates for random system capacity from high-fidelity finite element models. This can be used to obtain mathematical maps from component to system reliability which can potentially enable system-level engineering. The gradients of these plots represent an important parameter that we term as ‘system reliability sensitivity’, which can be interpreted as the contribution of an individual component to overall system safety. Furthermore, for at least a certain class of structural systems whose failure is governed by cascading collapse of several redundant components (for example, screw connections between a floor diaphragm and structural framing), simpler approximate models as well as analytical expressions for system reliability are available. These can be used to study the propagation of important performance indices such as ductility and uncertainty from component to system level and to analytically predict the system reliability sensitivity. Finally, the reliability sensitivities can directly be used to optimize component designs.

REFERENCES

[1] R.B. Corotis, A.M. Nafday, Structural System Reliability using Linear Programming and Simulation, Journal of Structural Engineering, 115 (1989) 2435-2447.

[2] A. Dey, S. Mahadevan, Ductile structural system reliability analysis using adaptive importance sampling, Structural Safety, 20 (1998) 137-154.

[3] T.V. Galambos, Systems Reliability and Structural Design, Structural Safety, 7 (1990) 101-108.

[4] M. Ghosn, F. Moses, Redundancy in highway bridge superstructures, in: NCHRP Report 406, Transportation Research Board, Washington, D.C, 1998.

[5] K. Imai, D.M. Frangopol, System reliability of suspension bridges, Structural Safety, 24 (2002) 219-259.

[6] F. Moses, System Reliability Developments in Structural Engineering, Structural Safety, 1 (1982) 3-13.

Author(s):

Aritra Chatterjee    
Virginia Polytechnic and State University
United States

Yibing Xiang    
University of Massachusetts, Amherst
United States

Cris Moen    
Virginia Polytechnic and State University
United States

Sanjay Arwade    
University of Massachusetts, Amherst
United States

Ben Schafer    
Johns Hopkins University
United States