Abstract:

An approximate formula using the lower and upper bound of the first simple bounds for estimate of the failure probability of structural systems is presented in the paper. In the approximate formula, the correlation between each of the two failure modes of the structural systems is considered but only the first failure probability of the failure modes is contained. Numerical examples are provided to demonstrate that the error is quitesmall. Usually the maximum error is within five per cent. The approximate formula possesses quite high accuracy and the computation is simple and convenient.

Key words: structural systems, failure probability, approximate formula