Failure frontiers: using load/capacity analysis and finite element modeling to assess the reliability of a mechanical system

摘要

Load versus capacity reliability analysis is used in conjunction with finite element analysis to explore the "reliability space" of a mechanical system as an alternative to obtaining failure data which would require costly destructive testing. The system being studied consists of two standard 20-foot shipping containers connected end-to-end using a special device. Concerns about the safety of such a connection prompted efforts to study the strength of the connection under load. A finite element model of the connected containers is constructed and is used to generate stress data based on a two-way matrix of loads and capacities. The empirical distributions of the stress levels in the model for each load/capacity combination are compared to the fixed yield strength of the steel alloy at a reliability level of 0.90 to determine failuro failure. The objective is to discover a trace, or "frontier", in two dimensions that defines the ultimate safe operating parameters of the system.