再访结构弹塑性动力响应的异常行为

ANOMALOUS BEHAVIOR REVI SITED: DYNAMIC RESPONSE OF ELASTIC PLASTIC ST RUCTURES

以ＬｅｅＬＨＮ的有限变形弹塑性连续体的最小加速度原理为基础，对理想弹塑性材料的两端铰支梁受矩形脉冲载荷作用时的动力行为进行了数值计算和分析，结果得到了梁的动力响应的异常现象，通过详细分析整个响应过程各个阶段梁的轴力、弯矩、曲率及纵、横向位移的分布和变化规律，从而澄清了人们对异常行为所做的物理解释的一些问题。

Based on the mi nimum principle of acceleration fo r the elastic plastic continua in finite deformation, the dynamic re sponse of an elastic perfectly pla stic simply supported beam subject ed to rectangular impulse load is studied with the help of a numeric al approach. The calculated result s once again show the anomalous be havior of the beam during its resp onse process. By carefully analyzi ng the instantaneous distribution of the bending moment, the membran e force, the curvature and displac ement during the response process, it is concluded that the interactive effect between the geo metry and material nonlinearities of th structure is the key reason of leading to the anomalous behavi or. This will be helpful for clear ing up some misunderstandings in e xplaining the problem before.