Abstract:
To improve the mechanical performance and industrialization degree of cold-formed steel (CFS)shear wall, a quick and reliable self-piercing riveting (SPR) was introduced from the field of mechanical engineering. Shear tests were conducted for the six full-scale CFS shear walls with SPR. The influences of rivet spacing, number of rivets in the steel frame, axial compression ratio and thickness of steel sheathing on the shear behavior and failure mechanism of shear walls were studied. According to the damaged state of components and the performance design objective, the limit value of the elastic story-drift angle was proposed. The effect of member thickness on shear performance and failure mechanism of CFS shear wall was discussed through numerical analysis, and the optimal design suggestion of the member thickness ratio between the steel frame and steel sheathing was obtained. Based on the calculation method of the shear capacity of SPR and the modified model of the effective strip method, the calculation method of the shear capacity of the CFS shear wall with SPR was proposed. The results show that the failure modes of CFS shear walls with SPR include sheet buckling, failure of SPR, distortional buckling of end stud and track tearing, and the rivet spacing and member thickness ratio are the key influencing factors. Within the range of rivet spacing 50 mm≤
S≤150 mm, the shear capacity and ultimate deformation of shear walls decrease linearly with the increase of rivet spacing. This rule can be used to effectively estimate the shear walls' bearing capacity and deformation capacity with other rivet spacing. It is safe and feasible to directly adopt the elastic story-drift limit in the specification of 1/300 for the CFS shear wall with SPR. Under the same condition, increasing the thickness of steel frame has a more significant effect on the improvement of shear capacity, and increasing thickness of steel sheathing has a better effect on the improvement of shear stiffness and ductility. It is suggested that the thickness ratio between the steel frame and the steel sheathing should not be less than 1.5. The modified calculation method of shear capacity can effectively predict the shear capacity of the CFS shear wall with SPR, and the error between the calculated value and the test value is less than 17.6%.