形状优化的装配式剪切型金属阻尼器力学性能研究

为了解决剪切型金属阻尼器应力集中和焊接区的热应力影响问题，提高其耗能效率，提出一种采用等应力线优化形状的装配式剪切型金属阻尼器。根据弹塑性力学J2理论寻找在一定外力条件下的等应力线，以等应力线同时进入屈服为条件设定剪切型金属阻尼器耗能片形状，并进一步推导了供设计使用的阻尼器初始刚度与承载力的计算式；建立了阻尼器的精细有限元数值模型，以模拟其低周往复加载的力学性能，分析阻尼器的变形模式与耗能能力，并进行了4个阻尼器的拟静力试验研究。试验与数值分析结果表明：提出的阻尼器初始刚度与承载力计算式的计算值与数值分析和试验结果吻合较好；形状优化阻尼器具有良好的低周疲劳性能与稳定的耗能能力；与未优化阻尼器相比，形状优化剪切型金属阻尼器的塑性变形分布更加均匀，最大累积等效塑性应变明显减小；采用全螺栓连接，易于更换。

Experimental study on mechanical behavior of assembled steel shear panel dampers with optimized shapes

In order to mitigate stress concentration, reduce the effect of hot welds, and improve the efficiency of energy consumption, an assembled steel shear panel damper with the shape optimized by stress contour lines is proposed in this study. The stress contour line is developed under a given load condition according to the J2 plasticity theory, and the optimized shape of the assembled steel shear panel damper is obtained by assuming the points on the same contour line yield simultaneously. The design formulas for the initial stiffness and bearing capacity of damper are further derived. To analyze the deformation mode and energy-dissipation capacity of the damper, mechanical behaviors of four dampers were simulated by use of sophisticated FEM models. Specimens were fabricated and tested quasi-statically then. Both numerical simulation and physical tests demonstrate that the initial stiffness and bearing capacity of damper design values match with the values of test and numerical simulation very well. The proposed metallic shear damper has a good low-cycle fatigue capability and stable energy-dissipation capacity. Compared with the non-optimized damper, the distribution of plastic deformation of the assembled steel shear panel damper with an optimized shape is more uniform, and the maximum accumulated equivalent plastic strain is reduced significantly. The dampers can be connected fully by bolts for easy replacement.