铰支墙—框架新型结构体系的损伤控制研究

发布时间：2018-08-29 11:24

【摘要】：震后可恢复性(Earthquake Resilience)已经成为了建筑结构体系的重要评价标准之一。作为高层建筑结构中最主要的抗侧力构件,钢筋混凝土剪力墙在近几次大地震中暴露出了震后可恢复性方面的缺陷。主要表现为连梁损伤严重、难以修复;剪力墙底部钢筋屈曲、混凝土压溃、剪切破坏明显,同样难以修复。针对上述两点问题,本文分别研究了剪切型金属阻尼器连梁和塑性铰支墙两种构件,建立两类构件的设计方法和简化数值模型。在此基础上运用连续化方法对铰支墙-框架结构体系中塑性铰支墙和消能连梁的强度和刚度需求进行了讨论。本文的主要研究内容如下:1.对国内多组普通RC连梁和剪力墙构件试验的结果进行了统计分析,其结果显示了两类RC构件的变形能力与设计参数之间的关联存在较明显的离散性。2.提出了带缝钢板阻尼器及跨中布置该阻尼器的剪切型消能连梁。本文通过对大剪跨比(r=3.0)的普通RC连梁和剪切型消能连梁的对比试验研究,结果显示,普通RC连梁和消能连梁试件的实测峰值荷载和名义屈服剪力值相差在4%以内。消能连梁阻尼器可以更早地进入屈服耗能状态,避免连梁混凝土部分遭受严重损伤。消能连梁变形的80%以上集中在阻尼器内,充分发挥了位移相关型阻尼器的耗能能力。阻尼器连接构造存在滑移,一定程度上影响了阻尼器性能的发挥。最后,建立了消能连梁的简化数值模型并验证了其适用性。3.针对剪力墙底部墙肢复杂的弯剪耦合作用机制,提出了抗弯/抗剪功能分离的塑性铰支墙并建立了相应的承载力和刚度设计公式。通过塑性铰支墙与普通RC剪力墙的对比试验证明,本文提出的设计方法可以更准确的获得塑性铰支墙不同性能目标下力学性能;塑性铰支墙具有更强的变形和耗能能力;塑性铰支墙的总变形中,弯曲变形占有绝对比重,避免了铰支墙发生剪切型破坏,保证了“强剪弱弯”的性能,从而避免了底部墙肢的不可修复损伤。4.对塑性铰支墙的主要设计参数进行了研究,给出了相关建议。建立塑性铰支墙的简化数值模型。其中,采用在纤维模型的截面附加剪切恢复力本构来模拟RC剪力墙的方法,以及采用零长单元模拟阻尼器连接段非线性行为的方法均根据试验结果进行了准确性验证。在此基础上研究了塑性铰支墙几何参数(墙肢宽高比r、铰支座高度比μ)、轴压比ν、阻尼器核心段初始刚度Ked对墙肢力学性能的影响,参数分析的结果显示,阻尼器性能的发挥主要受几何参数的影响,建议将塑性铰支墙布置在结构底部加强层范围内,高宽比r≤1.0,同时,铰支座的布置高度不宜超过铰支墙高度的60%。在满足阻尼器极限变形要求的前提下,通过选择更大的高度比μ和初始轴向刚度Ked更大的阻尼器,可以使塑性铰支墙获得更高的承载力和刚度。5.采用连续化设计,对铰支墙结构和铰支墙-框架结构在三种常见类型的水平荷载作用下的效应进行分析。结果表明,连续化设计方法可以得到铰支墙结构的结构响应,内力和变形计算公式中均显出铰支墙所在层的性能对结构响应的影响比较明显。
[Abstract]:Earthquake Resilience has become one of the important evaluation criteria of building structure system. As the most important lateral resistance member of high-rise building structure, reinforced concrete shear wall has exposed the defect of post-earthquake restorability in recent large earthquakes. In view of the above two problems, the design method and simplified numerical model of shear-type metal damper coupling beam and plastic hinged wall are studied respectively in this paper. The main contents of this paper are as follows: 1. Statistical analysis of the test results of several groups of RC and shear wall members in China shows that there is an obvious correlation between the deformation capacity and design parameters of the two types of RC members. Discreteness. 2. A steel plate damper with slits and a shear-type energy dissipation coupling beam with the damper in the middle of the span are proposed. The experimental results show that the difference between the measured peak load and nominal yield shear force of the ordinary RC coupling beam and the shear-type energy dissipation coupling beam with large shear span ratio (r=3.0) is 4%. Less than 80% of the deformation of the energy dissipation coupling beam is concentrated in the damper, which makes full use of the energy dissipation capacity of the displacement-dependent damper. Finally, a simplified numerical model of the energy dissipation coupling beam is established and its applicability is verified. 3. In view of the complicated Bending-shearing coupling mechanism of the shear wall at the bottom of the wall, the plastic hinged wall with separated bending and shearing functions is proposed and the corresponding design formulas of bearing capacity and stiffness are established. Experiments show that the proposed design method can more accurately obtain the mechanical properties of the plastic hinged wall under different performance objectives; the plastic hinged wall has stronger deformation and energy dissipation capacity; the bending deformation occupies an absolute proportion in the total deformation of the plastic hinged wall, avoiding the shear failure of the hinged wall, and guaranteeing the "strong shear and weak bending" of the total deformation. 4. Major design parameters of the plastic hinged wall are studied and relevant suggestions are given. A simplified numerical model of the plastic hinged wall is established. Based on the experimental results, the effects of geometric parameters of plastic hinged wall (width-height ratio r, height ratio of hinged support mu), axial compression ratio_and initial stiffness of the damper core on the mechanical properties of the wall are studied. The results of parameter analysis show that the damper is effective. It is suggested that the height-width ratio R < 1.0 and the height of the hinged support should not exceed 60% of the height of the hinged wall. On the premise of satisfying the limit deformation requirement of the damper, the height of the hinged support should be greater than that of the Mu and the initial axial stiffness Ked. Large dampers can increase the bearing capacity and stiffness of plastic hinged walls. 5. The effects of hinged walls and hinged walls-frame structures under three common types of horizontal loads are analyzed by using the continuous design method. The results show that the structural responses, internal forces and variations of hinged walls can be obtained by the continuous design method. It is shown in the formula that the performance of the hinged wall is more obvious to the structural response.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TU973

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