Seismic response investigation of 1/20 scale container crane through shake table test and finite element analysis

Abstract

This paper summarizes all detailed results obtained from a series of shake table testings of a 1/20 scale container crane with friction and pin boundary conditions at the Seismic Research and Test Center in South Korea and compared them with those from its finite element analysis (FEA). The tested 1/20 scale container crane was initially designed based on the similitude laws with scaling factors proportional to the sectional properties and dynamic characteristics of a commonly used full-scale crane. To determine experimental natural frequencies of the tested crane, a white noise test was conducted on the shake table. Then, three different ground motions, including Manjil Iran Abbar, Nahanni Canada, and Mineral Virginia, were individually applied in a trolley-boom direction to the crane placed on the shake table to secure its seismic responses, especially for derailment, uplift and drift. A finite element model of the tested crane was also created using multi-frame elements available in commercially used FEA software and simulated to replicate the testing results. Key findings revealed that the effect of the boundary conditions did not significantly affect the mode shapes and frequencies of the tested crane, but the drifts of the crane with the friction boundary condition resulting from each of the ground motions changed substantially as compared to those from the crane with the pin boundary condition. The derailment displacement at the landside legs of the tested crane was also found to be 12.5 mm for the Manjil Iran and Nahanni Canada earthquakes and 11.5 mm for the Mineral Virginia earthquake. The results from the testing were, largely, in good agreement with those from the FEA.