设置剪切钢板阻尼器的组合框架结构消能减震体系抗震性能研究

The metallic dampers can effectively decrease the seismic response of the structures and minimize the damage of the key components, which have been widely used in the passive energy dissipation system recently. As a popular choice of base material for metallic dampers, the low-yield-point steel behaves good ductility and excellent energy dissipation capacity, which enables the damper devices to make full potential of the elasto-plastic deformation and energy consumption of the metal. In this project, a new type of shear panel damper made of low-yield-point steel is devised to take the advantages in both optimum configuration and material utilization, which possesses the favorable characteristics of low yield strength, large initial stiffness, high energy dissipation capacity and easy replacement. This kind of damper is planned to be applied to the steel-concrete composite frame structure as a passive energy dissipation device, with its working mechanism and optimization design being intensively studied. This project focuses on the mechanical behavior, numerical model and design method of the low-yield-point steel shear panel damper, which is planned be divided into the following three levels as material, damper component and structural system. First, the cyclic loading tests will be carried out to the low-yield-point steel coupons. The elasto-plastic constitutive model is supposed to be proposed for elaborately describing the observed nonlinear behavior of the steel. In addition, the full-scale tests and refined finite element simulations will be conducted to the shear panel dampers, thus the efficient macroscopic numerical model can be correspondingly developed through the parameter analysis. Finally, the large-scale numerical analysis and parameter analysis are planned to be performed for the composite frame structures equipped with the energy dissipation devices, and then the evaluation and designing approach will be proposed for improving the seismic performance of the structural system.

金属阻尼器能够有效减小结构地震响应并降低关键构件的损伤，在消能减震结构体系中得到日益广泛的应用。近年来推广的低屈服点钢材具有优良的塑性变形和滞回耗能能力，为阻尼器充分发挥金属材料的弹塑性耗能能力提供了新选择。本项目拟结合新材料和新构造的双重优势，研发一种具有屈服位移小、初始刚度大、耗能能力强、易于修复更换等特点的组合式低屈服点钢剪切型阻尼器，并深入研究其应用在钢-混凝土组合框架结构中的工作机制和优化设计方法。针对目前对该种阻尼器受力性能、计算模型及设计方法上的认知不足，将开展材料、构件及体系三个层面的递次研究：首先基于低屈服点钢的循环材性试验，提出能够精准模拟其非线性力学行为的弹塑性本构模型；然后利用剪切钢板阻尼器的足尺模型试验及精细化数值分析，揭示其受力机理并开发适用的阻尼器高效计算单元；最后通过组合框架结构消能减震体系的大规模数值模拟及参数分析，提出其抗震性能评价理论及优化设计方法。

金属阻尼器作为不依赖外部能量输入的被动消能装置，能通过金属材料滞回变形耗散能量来有效减小结构地震响应并降低关键构件的损伤，在结构设计中得到日益广泛的应用。本项目利用具有优良塑性变形和滞回耗能能力的低屈服点钢材，同时结合新材料和新构造双重优势，研发了一种具有屈服位移小、初始刚度大、耗能能力强、易于修复更换等特点的组合式低屈服点钢剪切型阻尼器。针对该种新型阻尼器在受力性能、计算模型及设计方法上的认知不足，项目通过模型试验、数值模拟、理论分析以及优化设计等手段，开展了材料、构件及体系三个层面的递次研究，完成的研究工作和取得的研究成果包括：（1）通过单调拉伸和循环加载试验，研究了BLY160低屈服点钢材的循环力学性能，标定了钢材的低屈服点、高强屈比、高延伸率等性能特征，着重针对其显著且特有的循环强化和软化现象以及应变历史依赖效应进行了对比分析；（2）基于混合强化弹塑性本构关系理论，建立了适用于低屈服点钢材的材料本构模型，精细刻画了钢材的循环强化及软化特征及其多阶段演变过程，并通过相应的数值算法和有限元计算平台MARC进行实现和应用；（3）完成了低屈服点钢剪切型阻尼器试件的拟静力往复加载试验，通过对比分析剪力-剪切变形滞回关系、变形特征、疲劳性能、耗能能力等试验结果，明确了包括腹板宽厚比、加劲肋布置、腹板开洞构造以及循环加载制度等因素的影响；（4）在阻尼器构件往复加载试验研究的基础上，分别利用材料层次和构件层次的改进，针对低屈服点钢剪切型阻尼器建立了基于壳单元的精细有限元模型和基于弹簧单元的宏观计算模型，准确模拟和分析了阻尼器的滞回行为和受力机理；（5）通过某单榀三跨十层的组合结构框架的算例，将阻尼器计算模型集成至COMPONA-MARC计算平台，合理预测和评估了结构自振特性、位移响应、塑性损伤状态以及破坏机制等抗震性能，建立了适用于组合框架结构耗能减震体系的弹塑性时程分析的工具。