防屈曲支撑的有限元模拟及滞回性能分析

Finite Element Simulation and Hysteretic-performance Analysis of Buckling-restrained Braces

结合防屈曲支撑拟静力实验的研究成果,本文采用有限元软件ABAQU S对其进行了数值模拟分析。在模拟过程中,应用金属Com b ine本构模型设置内芯钢板材料属性。该模型是对传统双线性本构模型的改进,模拟结果很好地符合了实验结果,同时验证了防屈曲支撑具有良好的减震耗能性能,其在轴向加载达到7倍屈服位移时,依然能保持良好的滞回特性。通过对模型中橡胶无粘结层的合理设置,研究了内芯钢板在失稳变形中无摩擦滑移与能量缓冲转化的形变特点。分析表明,当外包约束强度和刚度足够时,内芯钢板在受轴向压力时只发生多波微幅弯曲失稳;随着内芯钢材与外包有效约束间隙的增大,支撑的失稳波幅也随之增大,支撑承载力与耗能能力显著降低。

In comparison with the pseudo-static test results of buckling-restrained braces（BRBs）,finite element analysis with ABAQUS software was carried out.Metallic Combine constitutive model,which improves the traditional bilinear-constitutive model,was used to lead in attribute of the kernel steel panel material.Result shows a better simulation relative to the test data.On the other hand,the simulation results verify that BRBs have a good damping performance under axial loading.Even though axial displacement increases up to seven times of the yield displacement,BRBs can still keep a good hysteretic performance.Based on reasonable setting of unbonded-rubber layers,the deformation characteristics of frictionless sliding and energy slow-release transformation of the kernel steel panel in unsteady deformation were researched.Analysis indicates that,when peripheral constraints supply enough strength and stiffness,the deformation of kernel steel panel under axial loading can only expresses a small flexural buckle with multiple waves.Simulation process also confirms that as the effective clearance between the kernel steel and peripheral constraint increases,the deformation wave is getting larger,at the same time,supporting capacity and energy dissipation capacity are significantly reducing.