Pretest analysis of a pipe system for high-level vibration response and failure

This paper reports on simplified elastic and inelastic analyses for high level vibration response and cyclic failure capacity of a prototypic light-water reactor pipe system which were carried out in a pretest environment. The system consists of a steam generator and a circulating pump with associated piping that has been tested on a shake table. Five analyses, ranging from standard linear elastic to detailed inelastic transient analysis, are compared in terms of response. With the inelastic analysis, subsequent failure analysis indicated that strain in the 3% to 4% range can be expected if the planned inputs are realized. Possible cyclic failure was predicted by through-wall cracking and leaking in 20 to 40 cycles of maximum strain range, caused by ratchet-fatigue in the pressurized system