Chapter04-荷载的可靠度模型和统计分析.pptVIP

Chapter 4 System Reliability Analysis of Structures Chapter 4: System Reliability Analysis of Structures 4.2 Reliability of Simple Systems 4.1 Elements and Systems 4.1 Elements and Systems …1 4.1 Elements and Systems …2 4.2 Reliability of Simple Systems 4.2 Reliability of Simple Systems …1 4.2 Reliability of Simple Systems …2 4.2 Reliability of Simple Systems …3 4.2 Reliability of Simple Systems …4 4.2 Reliability of Simple Systems …5 4.3 Reliability Bounds for Structural Systems 4.3 Reliability Bounds for Structural Systems …1 4.3 Reliability Bounds for Structural Systems …2 4.3 Reliability Bounds for Structural Systems …3 Chapter4: Homework 4 * * 4.3 Reliability Bounds for Structural Systems 4.1 Elements and Systems Contents Chapter 4 System Reliability Analysis of Structures There are two extreme types of structural elements that are commonly considered in system reliability analyses. These extreme types are brittle members and ductile members. A member is classified as brittle if the member becomes completely ineffective after it fails. A member is classified as ductile if the member is able to maintain its load-carrying capacity after it fails. Load Displacement Displacement Load Brittle member Ductile member In conducting system reliability analysis of structures, it is convenient to distinguish brittle and ductile members by using different symbols. Load Displacement Displacement Load Brittle member Ductile member Chapter 4 System Reliability Analysis of Structures 4.2.1 Reliability of Series Systems ? Consider a series system with n elements. Let represent the event “safety of the ith element”, represent the event “failure of the ith element”. S and F represent the events “safety” and “failure” of the system respectively. Assume that all failure events are all statistically independent, we have The probability of failure of the system is larger than that of either element. 4.2.2 Reliability of Parallel Systems Consider