摘要
To improve the efficiency and amplify the exciting force of a shake table,a novel variable stiffness mechanism(VSM)constructed by four leaf spring-lever combinations(LSLCs)was designed.Three VSMs were installed in parallel on the traditional hydraulic shake table to constitute a resonant shake table(RST).The static model of the VSM and the dynamic model of the RST were constructed by considering the large deflection of leaf springs and the geometrical nonlinearity of L-shaped levers.The variable stiffness property of LSLCs was analyzed and verified through static experiments.The simulation and vibration experiments on the dynamic properties of the RST prototype were conducted.The results show that compared with traditional shake tables,the RST consumes lower exciting force in a specified frequency bandwidth when outputting the same displacement of vibration.Under a harmonic vibrational excitation,the RST is effective for vibration enhancement using broadband frequency resonance and can save energy to some extent.The broadband resonance technology exhibits considerable potential in practical engineering applications.
为提高振动台效率、放大激振力,设计了一种由4个板簧-杠杆组合机构(LSLC)构成的新型变刚度机构(VSM),并将3个VSM并联安装在传统液压振动台上,构造出共振式振动台(RST).考虑钢板弹簧的大挠度和L形杠杆的几何非线性,建立了VSM的静力学模型和RST的动力学模型.分析并实验验证了LSLC的变刚度特性,同时仿真并实验研究了RST的动力学特性.结果表明,与传统振动台相比,RST在特定频率范围内输出相同的振动位移情况下所需激振力更小.在谐波激励下,RST可以通过宽频共振实现振动增强,从而在一定程度上降低功耗.宽频共振技术在实际工程中具有较大的应用潜力.
基金
The National Natural Science Foundation of China(No.41876218,51905210)。
