This proceedings volume contains 38 papers presented at the 4th Working Conference on "Rel iability· and Optimization of Structural Systems", held at the Technical University of Munich, Germany, September 11- 13, 1991. The Working Conference was organised by the IFIP (Interna tional Federation for Information Processing) Working Group 7.5 of Technical Committee 7 and was the fourth in a series, following similar conferences held at the University of Aalborg, Den mark, May 1987, at the Imperial College, London, UK, September 1988 and at the University of California, Berkeley, California, USA, March 1990. The Working Conference was attended by 54 participants from 16 countries. The objectives of Working Group 7.5 are: • to promote modern structural systems optimization and reliability theory, • to advance international cooperation in the field of structural system optimization and reliability theory, • to stimulate research, development and application of structural system optimization and reli ability theory, • to further the dissemination and exchange of information on reliability and optimization of structural systems • to encourage education in structural system optimization and reliability theory. At present the members of the Working Group are: A. H.-S. Ang, U.S.A. M. Grimmelt, FRG G. A ugwti, Italy N. C. Lind, Canada M. J. Baker, UK H. O. Mad&en, Denmark P. Bjerager, Norway R. E. Melcher~, Australia C. A. Cornell, U.S.A. F. Mo~e~, U.S.A.

Inhalt
Lectures.- Bridge Loading, Reliability and Redundancy: Concepts and Applications.- Recent Developments in Stochastic Finite Elements.- Simulation in Time-Invariant and Time-Variant Reliability Problems.- Numerical Techniques for Design Sensitivity Analysis of Structural Systems.- Reliability Analysis in Ship Design.- Short Presentations.- Life Cycle Model for Offshore Installations.- Foundation Reliability of Anchor Block for Suspension Bridge.- Structural Reliability Analysis by Stochastic Dependence Models and Matriceal Techniques.- A Survey of the Reliability Methods Approach in Some Codes for Structural Design.- Factors in Structural System Reliability.- Effectivity Factor Method in Structural Reliability.- Reliability Method to Solve Mechanical Problems with Implicit Limit States.- Strategies for Optimal Design of Structural Systems.- A Probabilistic Approach to the Analysis of Composite Panels Containing Delaminations.- Fatigue Life Estimation of Existing Bridge using 3-D FEM and Live Load Simulation.- Bayesian Model Assessment: Methods and Case Studies.- Multicriteria Optimization of Elasto-Plastic Bar Structures.- First Excursion Probabilities for Low Threshold Levels By Differentiable Processes.- Reliability Analysis of Structural Systems by using the Stochastic Finite Element Method.- Selection and Refinement of Random Field Mesh in Finite-Element Reliability Methods.- Experiences in System Reliability Optimization Including Damage Constraints.- On the Distribution of Local Extremes, Ranges and Means of Gaussian Process.- Reliability of Girder Bridges.- Reliability Evaluation Methods for Systems with Complex Limit States.- Reliability-Based Optimum Design for Multiaxial Fiber Reinforced Laminate Systems.- The Reliability of Bar Structures in the Light of the Shakedown Theory.- Reliability of the Bridge with Respect to Fatigue Crack Propagation.- Reliability Based Inspection Strategy for a Highway Bridge.- Optimal Inspection and Repair Strategies for Structural Systems.- Incremental Load Formulation for Generating Limit States in the Reliability Analysis of Non-Linear Systems.- On the First Excursion Probability with Random Threshold.- Stochastic Programs for Reliability of Systems with M-P Interaction.- MBB-LAGRANGE: A General Structural Reliability and Optimization Structural System.- A Comparison of Some Algorithms for Reliability Based Structural Optimization and Sensivitity Analysis.- Stochastic Approximation Methods in Structural Design.- Cost Optimal Design of a Bridge Pier Foundation.- Index of authors.