Mode matching to enhance nonlinear response of local defect resonance
Mode matching to enhance nonlinear response of local defect resonance
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DOI：
10.1016/j.jsv.2019.114916
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发表时间：
2019-08
影响因子：
4.7
通讯作者：
I. Solodov;M. Kreutzbruck
中科院分区：
文献类型：
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作者：
I. Solodov;M. Kreutzbruck
局部夹杂物和缺陷中机械共振的激活能够将输入声能直接传送至缺陷，从而显着增加其振动幅度并转变为非线性状态。然而，在这种以基模激励的非线性谐振器中生成的高次谐波与高阶谐振不匹配，这阻止了谐振器的最大高次谐波响应的充分发展。在实验中，研究了有机玻璃板中圆形平底孔的模拟缺陷的非线性谐振响应。测量在基本谐振频率下激励的传统二次和三次高次谐波响应，并用于评估谐振器的背景非线性参数。然后，随着激励频率的改变，使二次和三次谐波与高阶谐振匹配，这些参数会增加几个数量级。对于分谐波激励也获得了类似的结果：在这种情况下，二次谐波始终与基波谐振频率匹配，因此表现出最大效率。
Activation of mechanical resonance in localized inclusions and defects enables to route the input acoustic energy directly to the defect that dramatically increases its vibration amplitude and shifts into nonlinear regime. The higher harmonics generated in such a nonlinear resonator excited at a fundamental mode are, however, not matched to the higher-order resonances that prevents full development of the maximal higher harmonic response of the resonator. In the experiments, the nonlinear resonant response is studied for a simulated defect of a circular flat-bottomed hole in a Plexiglas plate. Conventional second and third higher harmonic responses for excitation at the fundamental resonance frequency are measured and used to evaluate background nonlinearity parameters of the resonator. An increase by orders of magnitude in these parameters is then obtained as the excitation frequencies are changed in order the second and third harmonics match the higher-order resonances. A similar result is also obtained for a subharmonic excitation: the second harmonic in this case always matches the fundamental resonance frequency and thus manifests the maximum efficiency.