Experimental and Numerical Study on the Effect of Heel Plate Length and Thickness on the Structural Integrity of Cold-formed Steel Roof Trusses

摘要

Cold-Formed Steel (CFS) is widely used as secondary framing material. Nowadays, the research of CFS as a primary steel roof truss system became more favoured. Therefore, it is very important to understand the behaviour of CFS roof trusses due to the uncertainty of the configuration of CFS roof trusses can affect its structural integrity. The objective of this research is to investigate the effect of heel plate length and thickness to the ultimate load capacity of CFS roof truss system. Nine different lengths and thicknesses of heel plate specimens were fabricated and subjected to concentrated loads until failure. The highest ultimate capacity for the experiment was 28 kN. Local buckling of top chords adjacent to the heel plate was the primary failure mode for all the heel plate. The results showed that the increment of the length and thickness of the heel plate had slightly increased the ultimate capacity, but decrease the deflection. The behaviour of the numerical results showed a good agreement with the experimental results. Numerical load capacity was higher than experimental load by an average ratio of 1.12. The behaviour of the bottom chord for both results was different after the load reached 20 kN.