基于优化原理框架结构梁柱合理线刚度比研究

框架结构初步设计中,梁柱截面尺寸估算分别按照梁的跨度及柱所分担的轴力来进行,由此得到结构抗侧刚度并不一定最大。框架柱的抗侧刚度不仅取决于自身的线刚度,还与其两端的框架梁对其约束程度有关,故存在1个合理的框架梁柱线刚度之比,使结构抗侧刚度最大。在保证梁柱材料总量相等的情况下,运用优化原理寻求框架结构等效抗侧刚度的最大值,此时框架结构梁柱线刚度比即为合理值,进而可确定梁柱的合理截面高度,并给出计算图表。算例结果表明,优化后的结构抗侧刚度较优化前明显增加,结构侧移明显减少。该方法简单、实用,可供初步设计使用。

Research on reasonable linear stiffness ratio of frames beam to column based on optimal principle

During the primary design of frames,the section sizes are estimated according to the beam span and the axis force bearded by column, but the structural anti-side stiffness will not be the maximum.The structural anti-side stiffness of column lies in not only the linear stiffness of columns,but also the beams restriction degree to the columns.There is a reasonable linear stiffness ratio of frames beam to column,thus the structural anti-side stiffness will be the maximum.On the condition of the equal material quantity,the linear stiffness ratio of frames beam to column is reasonable when the equivalent anti-side stiffness is the maximum by the non-linear optimal principle,and the reasonable section height can also be obtained.Some diagrams were given,and an example was taken to find that the structural anti-side stiffness increased and the lateral displacement decreased obviously after the optimization.It shows that this method is accurate,convenient and applicable to the preliminary stage of design.