Seismic protection of modular buildings with galvanised steel wall tracks and bonded rubber units: Experimental and numerical study

Abstract

This paper presents the test results of full-scale truncated wall tracks with galvanised steel sliding surfaces and a fully assembled full-scale slider device. Initially, 12 tests were conducted on three pairs of full-scale truncated wall tracks (400 mm long). Following the initial 12 tests, three further tests were conducted with 100 loading cycles to determine the effect of number of cycles on friction coefficient of the sliding wall tracks. Besides, 9 dynamic tests were completed on fully assembled full scale slider device, and in each test, a normal load was applied constantly. The numerical models were then developed and validated against the test results from both the truncated wall tracks with galvanised steel sliding surfaces tests and fully assembled full-scale slider device tests. With the galvanised sliding surfaces, the coefficient of friction (CoF) remains relatively constant initially and then increases with the number of loading cycles as the surfaces roughen. The average CoF for the initial constant range is calculated to be 0.144 for the three further 100-cycle friction tests with normal loads of 1.905, 4.021 and 6.137kN applied, respectively. From the initial 5-cycle friction tests, it is concluded that the dynamic sliding velocity has minimal influence on the CoF. However, at the quasi-static velocity, the CoF is higher due to the predominance of the stick–slip behaviour which results in significant fluctuations of the friction force as seen in the test results. The fluctuations of the friction force were caused by the bowed webs of the wall tracks.