荷载相关的结构刚度中心概念及算法

Concept and algorithm of load-correlating center of rigidity of building structure

通过研究给定的立面分布荷载在建筑结构楼面上的作用点位置对结构反应的影响,提出了荷载相关的结构刚度中心概念,荷载相关刚心同时依赖于结构的刚度性质和荷载分布。为了全面衡量结构的变形和内力反应,选取结构的总应变能作为扭转反应的量化指标,通过结构总应变能的极小化导出了荷载相关刚心的计算式。算例表明:当沿立面分布的水平荷载的作用位置由"传统刚心"移动到与其对应的"荷载相关刚心"上时,结构的扭转变形将明显减小,故结构中各楼层质心与其荷载相关刚心之间的偏心距可作为衡量地震作用下结构抗扭布局合理性的有效指标,并可用于指导结构的抗震设计。

In this paper, by investigating the influence upon the structural response of the points of force application for the known load pattern, the concept of load-correlating center of rigidity of building structure is developed, which depends on both the structural stiffness property and the load distribution. To take the structural responses of deformation and internal force into consideration comprehensively, the total strain energy of the structure is selected as the measurement of the structural torsional response intensity. By minimizing the response strain energy of the building structure, the explicit calculation formulas for the load-correlating rigidity center is derived. Through computation and comparison for several typical example structures, it is found that the structural torsional deformation decreases observably if the points of force application for the vertical distributed load are moved from its traditional rigidity centers to the load-correlating ones, which shows that the eccentricities between the centers of mass and the load- correlating centers of rigidity can be taken as a set of valid parameters to measure the performance of the torsional resistance of the structural seismic design scheme, and then, to provide guidance for the seismic design of building structure.