Modified DSM framework for limit states prediction of simply-supported Z-section purlin with sheeting

Abstract

A framework to predict the limit states of a single span unbridged Z-section purlin restrained by sheeting under uplifting wind load is presented. The flexural–torsional buckling of the member takes into account the diaphragm effects and the effect of load eccentricity on the warping-torsional behaviour of the purlin. The limit state loading for flexural–torsional buckling when under bi-moments and biaxial bending moments is then calculated. The variation of the signature curve of the Z-section member is also studied with the finite strip method. The interaction of different buckling behavior and limit states loadings is studied with the Direct Strength Method resulting in a reduction of load factor on the applied moment. The proposed model is then calibrated with a database of 45 single span specimen tests with good results. The proposed framework has been demonstrated feasible and accurate for limit states prediction of Z-section single span purlin with sheeting.