基于刚度和抗弯承载力需求的梁柱外伸端板连接优化设计

Optimal design of beam-column extended end-plate connections based on stiffness and flexural bearing capacity requirements

在现有的半刚性钢框架设计方法中,一般先假定梁柱半刚性连接的刚度,然后将假定的节点刚度代入框架中进行框架的整体计算,完成钢框架的梁柱设计后再进行梁柱节点的设计。梁柱半刚性节点的刚度和抗弯承载力同众多的节点构造变量相关,往往需要多次的试算才可以设计出满足假定刚度要求的节点,设计过程复杂,不利于在工程中的应用。据此,将节点刚度和抗弯承载力需求作为约束条件、节点成本最低作为目标,将外伸端板节点的设计问题转化为数学优化问题。采用组件法计算外伸端板节点的刚度和抗弯承载力,用增强精英保留遗传算法对优化问题进行求解。通过算例表明本文所采用的节点优化设计方法可以完成特定刚度和抗弯承载力需求的外伸端板节点的优化设计,优化结果表明了随着节点刚度需求的增大,节点刚度对框架的受力影响下降但节点的费用不断增加,因此有必要在半刚性钢框架整体设计中考虑节点刚度的合理设计。

In the existing design methods of semi-rigid steel frames,the stiffness of semi-rigid beam-column connections is generally assumed before the overall calculation of the frame,and the beam-column connections are designed after completing the beams and columns design of the steel frame.However,the stiffness and flexural bearing capacity of beam-column semi-rigid connections are related to many joint construction variables and the calculation relationship is complex.It often takes several trial calculations to design the joints that meet the assumed stiffness requirements,and the design process is complex.It is not conducive to the application in engineering.Accordingly,there is taken the requirements of joint stiffness and flexural bearing capacity as constraints and the lowest joint cost as the goal,and transforms the design problem of extended end-plate connections into a mathematical optimization problem.The component method is used to calculate the stiffness and bending capacity of extended end-plate connections,and the enhanced elite retention genetic algorithm is used to solve the optimization problem.The numerical example shows that the joint optimization design method adopted in this paper can complete the optimal design of extended end-plate connections with specific stiffness and bending bearing capacity,and the optimization results show that with the increase of joint stiffness demand,the influence of joint stiffness on the frame decreases,but the joint cost increases continuously,so it is necessary to consider the reasonable design of joint stiffness in the overall design of semi-rigid steel frame.