真三轴冲击试验中加载杆变截面段应力波的传播特性分析

发布时间：2018-05-02 21:33

本文选题：冲击实验 + LS-DYNA　；参考：《矿冶工程》2017年02期

【摘要】：利用有限元软件LS-DYNA模拟了应力波在真三轴动静组合加载试验系统"圆-方"变截面段中的传播过程,分析了不同形式和不同等级脉冲作用下杆中应力波的传播特性和衰减规律。结果表明:应力波经过变截面段后发生衰减,其中半正弦波能很好地保持波形,而梯形波会发生振荡,变截面段能吸收其中的高频振荡部分;若为细长杆,对于不同脉冲波形及不同横截面形式,均可忽略杆的横向惯性效应以及波的弥散效应,若杆横截面显著变化,横向惯性效应不可忽视,横截面上的应力分布会不均匀,波形弥散也会加重,并且随着脉冲增强,变截面段的横截面应力分布均匀性变差;应力波经变截面段后的衰减约为6.55%,圆杆段和方杆段中应力波峰值随脉冲等级增加而呈线性增长,应力波上升沿时间随传播距离和脉冲等级增加而逐渐增大。
[Abstract]:Using finite element software LS-DYNA, the propagation process of stress wave in the "circular square" section of the true triaxial dynamic and dynamic loading test system is simulated, and the propagation characteristics and attenuation law of the stress wave in the bar under the action of different forms and different grades of pulses are analyzed. The results show that the stress wave attenuates after passing through the variable cross section, in which the half sine wave can keep the waveform well, while the trapezoid wave oscillates, and the variable cross section can absorb the high frequency oscillation part of the wave, if it is a slender rod, For different pulse waveforms and different cross section forms, the transverse inertia effect and wave dispersion effect can be ignored. If the bar cross section changes significantly, the transverse inertia effect can not be ignored, and the stress distribution on the cross section will be uneven. The waveform dispersion will also increase, and with the increase of pulse, the stress distribution of the cross-section of the variable section becomes worse. The attenuation of stress wave through variable cross section is about 6.55. The peak value of stress wave increases linearly with the increase of pulse grade in round bar and square bar, and the rising time of stress wave increases with the increase of propagation distance and pulse grade.
【作者单位】：空军工程大学机场建筑工程系;中国人民解放军94940部队;西北工业大学力学与土木建筑学院;
【基金】：国家自然科学基金(51378497)
【分类号】：TD313

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