Transient State Tests of Light Gauge Steel Single Shear Screwed Connections

Abstract

The current design rules on screwed connections of light gauge steel for cold-formed steel structures are applicable for ambient temperature condition only. Investigation of screwed connections at elevated temperatures is limited. In this study, 30 single shear screwed connection specimens fabricated from G550 0.42mm and G500 1.20mm light gauge steels were conducted by using transient state test method. The tests were performed at three different load levels of 25%, 50% and 75% of the failure load at ambient temperature. The critical temperature and the corresponding displacement of screwed connections were obtained from the transient state test curves. The connection strength deterioration obtained from the transient state tests was compared with that obtained from steady state tests. The test strengths obtained from the transient state tests are similar to those obtained from the steady state tests. The tilting and bearing failure was observed in the transient state tests, which is consistent with the failure mode observed in the steady state tests.