Shear Tests of Aluminium Lipped Channel Beams

Abstract

Recently, the use of aluminium sections as primary load bearing members has increased significantly in the building industry. Aluminium as a new constructional material has several advantages in building structures. Corrosion resistance and durability are very notable among its features, making the material long-lasting in the building systems. Moreover, high ratio of strength-to-weight, reduced cost of transportation and ease of erection and fabrication are the other important features of this material. The popularity of aluminium structures has attracted attention regarding the efficiency and design of many sections, and lipped channel beam (LCB) is one of these sections. The vulnerability of aluminium in buckling due to low elastic modulus compared to steel has raised the issue about the shear failure of aluminium LCBs. Hence an experimental study was conducted to investigate the shear behaviour of LCBs and to verify current design rules. Shear tests have been carried out using commonly available ten different aluminium LCBs. The test specimens were loaded at mid-span at the shear centre until failure. The three modes of shear failure including shear yielding, inelastic, and elastic shear buckling were investigated in this study. The results obtained from the tests were then compared with the predictions using the current Aluminium shear design rules in the Australian/New Zealand standard. The comparison showed that the current shear design rule is unsafe to predict the shear capacity of aluminium LCBs specifically in the yield and inelastic regions. Hence, appropriate modifications were proposed for the current design rules to predict the shear strengths of aluminium LCBs and the accuracy of the proposed design rules were verified against test results. This paper presents the details of this experimental study and the improved design rules to predict the shear capacity of aluminium LCBs.