Chapter 26 - Reliability-Based Design and Code Calibration

Abstract

This chapter discusses reliability-based design and code calibration. The most important applications of structural reliability methods are perhaps reliability-based design and calibration of the safety factors in the design codes. General design principles used in practice are outlined in the section general design principles. Reliability-based design is one of the design methodologies, but is highlighted as a separate section in this chapter. The important general design principles explained here are concept of safety factors, allowable stress design, load and resistance factored design, plastic design, limit-state design (LSD), and life cycle cost design. This chapter discusses the reliability-based design effectively. The role of safety factor in traditional deterministic design is to compensate for uncertainties affecting performance. The various terms and steps involved in a reliability-based code calibration are defined and presented. They include code calibration principles, code calibration procedure, and simple example of code calibration. Numerical example for tubular structure is given in this chapter for case description, design equations, limit-state function, uncertainty modeling, target safety levels, and calibration of safety factors. The main objective of reliability-based calibration of tubular joint design is to achieve the optimal set of partial safety factors on the basis of a uniform reliability level. This chapter covers the main topic of the uncertainty analysis to identify and quantify the different sources of uncertainties that are present, and to decide how to take them into account in the subsequent reliability analysis.