二维振动结构的颗粒阻尼实验

采用非接触式激光测振仪对自由端附有空腔的L型悬臂梁进行了颗粒阻尼减振实验,考查了空腔尺寸对颗粒阻尼的影响规律,得到了二维颗粒阻尼的相关特性.结果表明:①非线性的颗粒阻尼能够显著地抑制结构振动,且阻尼值至少比金属材料阻尼大一个数量级;②二维颗粒阻尼在各个方向上具有相似的阻尼特性,随无量纲加速度的增加,颗粒阻尼先增大后减小...

Experimental study of particle damping for a two-dimensional vibrating structure

By use of a non-contact laser vibrometer, experiments have been done on an L-shaped beam with a cavity attached to the free end to investigate the damping properties of particle damping for structure vibrating in two directions under different cavity sizes. The experimental results show that: (1)The nonlinear particle damping, which could be at least one order of magnitude higher than the intrinsic material damping of metals, can significantly suppress the vibration of structures. (2)The features of two dimensional particle damping are almost the same in each direction, with the increase of dimensionless acceleration amplitude, particle damping first increases and then decreases, meaning that there is a critical dimensionless acceleration amplitude causing the highest damping. (3)Particle damping as well as the critical dimensionless acceleration amplitude corresponding to the damping peak increases as cavity sizes increase. The experimental results could provide a reliable basis for the numerical simulation of particle damping in two dimensions.