考虑高宽比和梁变形影响的防屈曲开缝钢板墙刚度研究

Study on stiffness of buckling-restrained slit steel plate wall considering aspect ratio and beam deformation

防屈曲开缝钢板墙具有良好的延性和耗能能力,外覆混凝土板可约束钢板的平面外变形,但不承担侧向荷载。以缝间弯曲杆数目为参数,通过有限元分析研究钢板墙高宽比的变化和边缘梁的弯曲变形对防屈曲开缝钢板墙抗侧刚度的影响。分析表明:在弯曲杆尺寸相同的条件下,钢板墙高宽比的增加对其承载能力的影响较小,但会导致单个弯曲杆的刚度明显降低,其主要原因是上下板带的弯曲变形明显增大;梁的弯曲变形会削弱对钢板墙的约束,导致钢板墙抗侧刚度下降可达40%。对大高宽比钢板墙提出了考虑上下板带弯曲变形的刚度修正计算式,可以较为准确地计算钢板墙的刚度。提出了考虑梁变形影响的钢板墙简化分析模型,并给出考虑梁变形影响的钢板墙刚度计算式。

The buckling-restrained slit steel plate wall（BRSSPW） has excellent ductility and energy-dissipating capacity.The two outside reinforced concrete panels are only for restraining the out-of-plane deformation of the steel plate,ignoring their contribution to the total lateral force resisting capacity.By means of a finite element analysis using the number of flexural links as a parameter,the effects of aspect ratio and bending deformation of boundary beams on the lateral force-carrying performance of BRSSPW were investigated.The analysis shows that： with the same geometry of the flexural links,the increase of BRSSPW aspect ratio has little effect on its ultimate lateral force capacity but causes a significant reduction of lateral stiffness of single flexural link of BRSSPW,which is mainly due to the large increase in the flexural deformation of upper and lower bands;the flexural deformation of boundary beams weakens the boundary restraint on BRSSPW and would cause a reduction in lateral stiffness of BRSSPW up to 40%.Modified formula for BRSSPW of large aspect ratio was proposed considering the flexural deformation of upper and lower bands.The proposed method is capable of predicting accurately its lateral stiffness.A simplified model considering deformable boundary beams and a relevant stiffness formula were proposed.