低屈服点钢板剪力墙结构基于性能的塑性设计

The research on low-yield-point steel used for the seismic energy dissipation components is more and more hot both at our country and abroad. The performance-based plastic design of low-yield-point steel plate shear wall will be carried out in this project.Two scale specimens in 1:3 ratio will be designed used for the horizontal low cyclic loading test and then the mechanical characteristics, yield sequence as well as deformation performance of structural members under different levels of seismic loads will be expected to investigate in this study. The failure mechanism of shear wall will further be analyzed and the elastic and plastic displacement limits for determining the performance goals are ultimately achieved. According to the four performance requirements and three seismic protection levels with different probability standards of the performance-based seismic design included in the latest《Code for seismic design of buildings》(2010 edition) in China, the corresponding different performance states of structural system for the performance requirements under all seismic levels will be represented and the damage description such as the yielding or buckling of low-yield-point steel plate shear wall is also microscopically given. Then, the specific damage degree will be quantified and corresponding inter-story drift range under the each performance state will also be defined. The elastic response spectrum method is used for the elastic design of structure and the displacement-based seismic design method is adopted in the structural elastoplastic design in order to put forward the performance-based seismic design method. At the same time, an example of detailed seismic design steps using the design method involved in this project will be provided. By using the incremental dynamic analysis method and improved modal static elastoplastic analysis method considering the effect of high order modes on system, the seismic safety assessment of low-yield-point steel plate shear wall structure will be carried out to analyze the plastic hinge forming rule of each member and obtain the structural performance points under performance requirements at all levels, as well as to finally check whether this designed system meets the corresponding requirements of different performance goals under all seismic levels. Therefore, A complete set of seismic performance-based design method for the steel frame - low-yield-point steel plate shear wall will be established based on the above achievements, which will promote the scientific and technological progress for the seismic design of new steel structural system.

国内外针对低屈服点钢制作抗震消能构件的研究正在兴起。本课题将对新型的低屈服点钢板剪力墙结构进行基于性能的塑性设计，拟设计缩尺模型试件，用于低周反复水平荷载试验，得到不同等级地震荷载作用下结构构件的受力特点、屈服顺序及变形性能等，分析剪力墙板的破坏机理，确定性能目标的弹性和塑性位移限值。结合四种性能要求和三种抗震设防水准，对在各设防水准下不同性能要求时结构的状态进行描述，并以宏观表现的形式给出相应的损伤描述，比如：低屈服点剪力墙板的屈服和屈曲等。而后量化具体破坏程度，定义出各性能状态对应的层间位移角范围。采用弹性反应谱法进行弹性设计，利用基于位移的抗震设计方法进行弹塑性设计，并给出工程实例的设计步骤。运用动力增量法和改进的模态静力弹塑性法对该体系的抗震安全进行评估，以此建立一套完整的钢框架-低屈服点钢板剪力墙的抗震性能化设计方法，这将促进国内钢结构新型结构体系抗震设计的科技进步。

国内外针对低屈服点钢制作抗震消能构件的研究正在兴起。本项目加工设计了低屈服点钢材的试样，对其主要力学性能进行了测试，得出了其本构关系，并与普通钢材进行了对比。同时，加工制作了低屈服点钢板剪力墙结构试验模型，通过在结构工程实验室分别进行二层和单层低屈服点钢板剪力墙结构的水平低周往复加载试验，着重研究了低屈服点钢板剪力墙结构的水平抗侧刚度、延性、极限承载力、耗能以及剪力墙板的变形和应力分布等特点，以此对试件做出合理的抗震性能评价。通过低屈服点钢板在受剪作用时的应力特征，推导出低屈服点钢板弹塑性剪切屈曲应力的理论公式。应用塑性折减系数来反映低屈服点钢板屈服后的应变硬化情况，并通过迭代过程计算得到不同宽厚比时的剪切屈曲强度，给出了低屈服点钢板墙的剪切屈曲强度-宽厚比关系曲线。根据《建筑抗震设计规范》和基于低屈服点钢板剪力墙“抗剪承载力”的设计方法分别设计了10层3跨、15层3跨、20层3跨和25层3跨的分析算例；基于“屈曲前屈服”的设计方法设计了10层3跨和20层3跨钢板剪力墙体系的分析算例。通过多条天然地震波和人工地震波数据，利用增量动力分析法绘制出结构的IDA曲线，对该结构体系在小震、中震和大震作用下的抗震性能进行评估。重点通过低屈服点钢板剪力墙结构的抗震性能试验，确定出剪力墙板的屈服和屈曲、弹性位移限值、塑性位移限值、结构的性能目标和结构损伤指标等参数，而后根据该结构体系的各相关性能参数，提出可应用于工程实践的基于性能的塑性设计方法。按照所量化的四个性能指标分别进行抗震性能化设计，详细地给出了10层低屈服点钢板剪力墙结构基于性能3和性能4的设计过程以及30层低屈服点钢板剪力墙结构考虑高振型影响基于性能3的设计过程。并利用能力谱法对设计好结构进行性能评估，分析结构在不同性能下的性能状态，以此建立一套完整的钢框架-低屈服点钢板剪力墙双重抗侧力体系的抗震性能化设计与抗震安全评估方法。