为了研究钢框架预应力支撑结构体系中拉索初始预拉力的取值方法,从理论上对钢框架预应力支撑结构体系进行分析,推导出预应力框架支撑结构体系拉索初始预拉力的取值公式,得到预应力拉索初始预拉力与结构层间位移角之间的关系.采用反弯点法,推导出预应力框架支撑结构体系的抗侧刚度计算公式,得到预应力框架支撑结构体系的抗侧刚度与构件的材料属性、截面属性、预应力拉索与水平面的倾角有关,与拉索的初始预拉力无关.基于推导出的预应力拉索初始预拉力和层间位移角的关系公式,提出一种预应力拉索初始预拉力的设计方法,通过算例验证了提出的预应力拉索初始预拉力设计方法的可行性,保证结构体系在设计的外荷载作用下,卸载索不退出工作,而增载索的安全储备提高了30%左右.
To study the design method of initial tension of cables in prestress-braced steel frame structure system, this structure system was theoretically analyzed. Formula of initial tension of cables in prestress-braced steel frame structure system was derived, it was obtained the relation of initial tension of cables and story drift angle. Based on inflexion point method, it was derived that formula of lateral stiffness of prestress-braced steel frame structure, lateral stiffness of the structure is related to material properties, section properties and angles between cables and horizontal plane. Based on the formulas derived in this paper, a design method of initial tension of cables in prestress-braced steel frame structure was proposed. Practicability of this method is proved through an example, this method can make sure the tension of cables is more than zero under designed exterior loads, and emergency capacity of cables is improved by 30% .