INTEGRATION OF RELIABILITY-BASED DESIGN OPTIMIZATION WITHIN CAD AND FINITE ELEMENT MODELS

摘要

High technology designs aim to define the best compromise between cost and safety. The Reliability-Based Design Optimization (RBDO) allows us to design structures which satisfy economical and safety requirements. However, in practical applications, the coupling between the geometrical modeling, the mechanical simulation, the reliability analyses and the optimization methods leads to very high computing time and weak convergence stability. Traditionally, the solution of the RBDO model is achieved by alternating reliability and optimization iterations (sequential approach). This approach leads to low numerical efficiency, especially when the structure geometry is described by efficient CAD models (such as B-spline or NURBS) which necessitate a great amount of data. In this case, the integration of the sequential RBDO approach with Finite Element Analysis requires lengthy computing time. In order to avoid this difficulty, we propose an efficient method, called the hybrid RBDO method, based on the simultaneous solution of reliability and optimization problems. In this paper, the efficiency of the proposed methodology is demonstrated on a finite element problem using CAD model description.