Seismic qualification by analysis of an overhead crane for nuclear industry

Abstract

The seismic qualification for the structural strength it is an issue for the assessment of the seismic safety of the Nuclear Power Plants. As regard the seismic strength of the Cranes it has to be demonstrated via (mostly) a numeric analysis that in the case of the unlikely event of an earthquake the crane isn’t breaking apart affecting thus the safety related neighboring equipment. The crane is required to maintain its integrity when subject to the Design Basis Earthquake when it is supposed to hoist the rated load. The goal of this article is to underline the procedure to be followed for nuclear industry cranes in order to obtain sound and credible results for equipment seismic qualification by using the unique analysis features of ANSYS 19. This study is meant to show how a complex structure of an overhead crane may be treated in order to have meaningful results for a decision whether or not such a structure is able to withstand the loads generated by a seismic event. The seismic event is not overloading the crane structure an in comparison with the hoisted load, the seismic stresses stay quite modest. By comparing the overall calculated equivalent stresses with the tensile yield strength we may pull the conclusion that the structure will resist. Based on all the above the crane is considered to be seismically qualified.