【摘要】 采用柔度法对两端固定梁在2个对称集中力作用下的加载全过程进行了弹塑性分析.分析结果表明,受力变形过程可分为4个阶段:弹性阶段;固定端附近产生塑性变形阶段;固定端为塑性铰而固定端附近弹塑性区卸载阶段;固定端保持为塑性铰而梁中部部分区域产生塑性变形直至形成塑性流动阶段.导出了纯弯段屈服时的曲率与弯矩的关系,给出了塑性铰处的相对转角及其引起的位移的计算方法.推导了加载各阶段的荷载、弯矩和位移计算公式,可供对超静定梁进行强度和刚度计算时参考.更多还原

【Abstract】 The elastic-plastic loading and deformation process of the beam fixed at two ends under uniformly-distributed loads is analyzed by using the flexibility method.The result of analysis shows that the deformation process can be divided into four stages,including the stage of elastic deformation of the whole beam,the stage of plastic deformation occurring in the region close to two fixed ends,the stage of unloading in plastic regions with two plastic hinges at the fixed ends,and the stage of plastic deformation till the occurrence of plastic yield at the middle of the beam with two plastic hinges at the fixed ends.The curvature and the bending moment relations in the pure bending zone at yielded are derived.The formulas for the load,the bending moment and the displacement at different loading stages are deduced.The computational methods for slope of the plastic hinge and for displacement are given.It can be referenced to calculate the intensity and rigidity of the beam.更多还原