ABSTRACT
A fully satisfactory estimate of the reliability of a structure is based on a system approach. In some situations, it may be sufficient to estimate the reliability of the individual structural members of a structural system. This is the case for statically determinate structures where failure in any member will result in failure of the total system. However, failure of a single element in a structural system will generally not result in failure of the total system, because the remaining elements may be able to sustain the external load by redistribution of the internal load effects. This is typically the case of statically indeterminate (redundant) structures, where failure of the structural system always requires that more than one element fail. A structural system will usually have a large number of failure modes, and the most significant failure modes must be taken into account in an estimate of the reliability of the structure.
