阻尼颗粒动态特性研究

Experimental Investigation on Damping Particle Dynamic Characters

在垂直简谐激励条件下,测量颗粒体对基础产生的冲击力,得到冲击力受约化加速度控制会经历一系列倍周期分岔的规律,并给出分岔周期冲击力的谐波分量表达式;通过稳态功率输入法得到阻尼颗粒产生的损耗功率和附加质量与激励的关系。试验结果表明,对于给定频率,损耗功率随激励幅值的增加单调递增;对于给定速度幅值,损耗功率随激励频率的增加呈现为:低频段迅速增大,而后递增速率减缓的过程。由颗粒体产生的附加质量存在明显的转捩点现象,转捩点之后,附加质量随激励幅值的增加而变小。

Particle dynamic characters are investigated for understanding its behaviors. The impact strength between the granular bed and the container bottom, controlled by normalized vibration acceleration, undergoes a series of period doubling bifurcations. A same expression for all the impact strengths with different period bifurcations is derived. The steady state power technique is used to estimate the dissipated energy and the dynamic mass. As a result, the dissipated energy takes some regularity depended on the velocity and the frequency. And there is a key point in which the dynamic mass can be suddenly changed. The dependence of the loss factor on the velocity amplitude and the frequency is verified and the contours of 3-D surface of the loss factor are introduced for validating the particle damper performance.