U型钢板力学性能受硬度和层数的影响分析

MECHANICAL PROPERTIES ANALYSIS OF U-SHAPED STEEL PLATES OF DIFFERENT HARDNESS AND NUMBERS OF LAYERS

U型钢板可作为限位器和阻尼器使用,设计4种U型钢板,分别采用软钢和硬钢制作,进行单推和推拉两种情况下的静力试验,结果表明,厚度较大的硬钢U型钢板易发生断裂;硬钢U型钢板比软钢具有更大的屈服荷载和屈服位移,更适合做限位器;硬钢的滞回曲线呈典型梭形,屈服后荷载仍有较大增长,软钢的滞回曲线呈平行四边形,屈服后荷载增长不大。推导了叠层U型钢板的屈服荷载、屈服位移和弹性刚度的计算公式,设计4种单层和叠层U型钢板,用ABAQUS有限元软件进行建模分析,有限元计算结果与理论分析一致;U型钢板分成n层后,弹性刚度近似折减为原来的1/n^2,屈服荷载近似折减为原来的1/n,屈服位移近似增大为原来的n倍。

U-shaped steel plates （USPs） can be used for displacement restraining devices or dampers. Single push and push-pull static tests of four kinds of USP made by mild steel or hardened steel were completed. The tests show that thick USPs made by hardened steel fracture easily. Hardened steel USPs provide greater yield load and yield displacement and are more suitable for displacement restraining devices than mild steel ones. Hysteresis curves of hardened steel USPs showed typical spindle shape, and the load increased significantly after yielding. Hysteresis curves of mild steel USPs are parallelograms, and the load increased a little after yielding. Formulae of yield load, yield displacement and elastic stiffness for laminated U-shaped steel plates （LUSP） are derived. Four USPs and four LUSPs were designed and analyzed by Abaqus. The calculation of finite element fits the theory well. The ratios of LUSP to USP in terms of elastic stiffness, yield load and yield displacement are 1/n^2, 1/n and n, respectively.