Interactive stability-oriented reliability-based design optimization

Recent advances in reliability methods, optimization as well as design sens itivity analysis have resulted in development of computational systems supp orting reliability-based design optimization (RBDO) processes for medium/la rge structures. For REDO the efficiency problems are critical and in order to get the optimum design a number of fast approximate methods have been re cently proposed. These methods, tested for rather small problems, show acce ptable accuracy and speed up computations considerably. However, when appli ed in the automated way to medium/large scale problems they may cause sever e convergence problems or lead to a poor local minimum after expensive comp utations. Convergence problems are manifested in a specially severe way whe n stability of structures is under consideration. Instead of an automated optimization procedure, an interactive approach is proposed. Implemented in the POLSAP-RBO system, it allows to combine effect ive interactive design methods with Visual capabilities to efficiently gene rate optimum design. The system allows to consider the local and global sta bility problems of truss structures. Interactive stability-oriented reliabi lity optimization of an offshore jacket and truss-column is discussed in de tail. (C) 1999 Elsevier Science S.A. All rights reserved.