变截面杆共轴撞击数值分析及其应用前景

 为对弹性杆共轴撞击这一应力波基础问题进行扩展研究，基于非线性动力学软件LS-DYNA建立了有限元模型，分析了共轴撞击的变截面杆的形态参数对波形的影响规律，探讨了应力波产生的机理，并对其应用前景进行了展望。结果表明,由于变截面效应，一定形态参数的变截面杆共轴撞击可以得到具备波阵面平滑上升，较长的前沿升时和消除了波形振荡等特性的应力波；该特性是变截面杆撞击这一过程的内在属性，主要由变截面段的最小半径控制，变截面段长度仅对局部形态产生影响，对加载速度的变化不敏感；半无限长的变截面杆共轴撞击规律可在应力波加工等领域应用。由此可见，该规律对基础性理论进行了扩展，应用前景广阔。

Numerical Analysis on the Coaxial Collision of Variable Section Bar and Application Prospect

In order to perform extensive research on the coaxial collision of elastic bar, finite element model was established based on LS-DYNA, the influences of the shape parameters of variable section bar on the stress wave were analyzed, producing mechanism of stress wave was discussed, and its application and development prospect in this field were also explored. The results show that, because of the variable section effect, the coaxial collision of variable section bar under conditions of some shape parameters can create the stress wave, which has the following characteristics: wave front rising is in the form of smooth concave curve, the rising time is longer and there is no waveform oscillations phenomenon. The characteristics are the intrinsic attributes of the coaxial collision of variable section bar, controlled mainly by minimum radius of variable section scope in bar, and length of variable section scope in bar exerts an influence on the partial difference; besides, the characteristics are not sensitive to the change of the loading speed. The laws obtained by the coaxial collision of variable section bar can be applied to many fields such as waveform shaping. Thus it can be seen, these laws extend the foundational theories, which can be of great theoretical and realistic significance, and moreover, its application prospect is wonderful.