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。
The stress wave propagation characteristics and attenuation law in a bar with 'round to square'cross section in a true triaxial test system with both dynamic and static loads was analyzed by using finite element software LS-DYNA to simulate the propagation process of stress wave under the different forms and different levels of stress pulse. Results show that a stress wave is attenuated after going through the variable cross section,in which the half-sine stress wave can stay as its original waveforms during the propagation process,but the trapezoidal stress wave will oscillate with the highfrequency oscillation absorbed by the variable section. As for a long and thin bar with different stress waveforms or crosssection shapes,the transverse inertia effect and dispersion effect can be ignored. However,if there's great change in the cross-sectional area,the transverse inertia effect can' t be ignored and can lead to an uneven stress distribution on the cross-section and the serious wave dispersion. Stress wave's amplitude attenuation is about 6.55% after going through a variable section. The peak value of stress wave in round and square sections increases linearly with an increase in the pulse level,and the rise time of stress wave gradually increases with the increasing of the stress pulse level and propagation distance.
出处
《矿冶工程》
CSCD
北大核心
2017年第2期11-15,19,共6页
Mining and Metallurgical Engineering
基金
国家自然科学基金(51378497)
关键词
冲击实验
LS-DYNA
真三轴
“圆-方”变截面段
应力波
传播特性
衰减规律
impact test
LS-DYNA
true triaxial
'round to square' variable section bar
stress wave
propagation characteristics
attenuation law
