| The bearing capacity behavior of six cold-formed steel Z section lapped continuous purlins under bending has been studied in this paper. According to joining forms, specimens are divided into two groups, whose spans are L=2060mm,1990mm,1870mm. Overlapping lengths are 180mm,250mm,370mm. Overlapping length and span percentages are 8%,12%,19%。The effect of overlapping length and constructional detail to lapped continuous purlins has been analyzed.This Paper uses the finite strip method software CUFSM and the new design method in cold-formed steel field (Direct Strength Method) to solve the specimens'load carrying capacity. The result shows that using Direct Strength Method to calculate the cold-formed steel continuous Z section purlins'load carrying capacity is reasonable. The deviation of evaluation and experimental value is about 10%. Moreover, this paper uses Direct Strength Method to further discuss the different number of spans to find the related modified formulas.Based on the experiment, the finite element program ABAQUS is applied to carry out the finite element nonlinear analysis of the cold-formed steel continuous Z section purlins under bending. Meanwhile, the method of coupling linear displacement is proposed to substitute for touching effect in the self-drilling screws in the overlapping part of lapped continuous purlins. The results of analysis show that it is ideal to use this method. The result of the finite element method, the result of the Direct Strength Method and the result of the experiment are much close to each other. These phenomena further prove that using Direct Strength Method to calculate the cold-formed steel continuous Z section purlins'load carrying capacity is reasonable.
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