共查询到18条相似文献,搜索用时 953 毫秒
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PVDF压电膜是一种柔软、质轻、高韧度塑料薄膜,可以根据需要制成各种形状,厚度的元件,与微电子技术结合,能制成多功能传感元件。PVDF压电膜传感器以其独特的性能在减振降噪、健康监测、形状自适应控制、损伤监测等方面发挥着重要作用。压电元件的非线性是影响其使用性能进一步提高的主要因素之一。 相似文献
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压电膜在振动控制中的应用及有限元分析 总被引:1,自引:0,他引:1
介绍了压电现象的基本原理及其在柔性结构主动减振中的应用,回顾了以往有限元法用于柔性结构振动主动控制分析的主要研究工作,提出了今后需要解决的问题。 相似文献
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压电薄膜在振动控制中的应用及有限元分析 总被引:2,自引:1,他引:1
介绍了压电现象的基本原理及其在柔性结构主动减振中的应用,回顾了以往有限元法用于柔性结构振动主动控制分析的主要研究工作,提出了今后需解决的问题。 相似文献
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针对工程中普遍存在的薄板结构振动噪声问题,提出了一种对加强筋位置分布进行拓扑优化的控制方法。通过有限元动力学分析结构的速度响应,代入由声辐射模态推导的声功率求解方程中得到声功率。建立以加强筋位置作为设计变量的拓扑优化数学模型,寻找声功率最小的加筋分布。算法中以声辐射模态灵敏度为指导,确定拓扑优化加筋的起始点和搜索过程。通过仿真计算结果表明,优化得到的加筋布局能有效地将声功率降低7.38dB,并讨论了收敛准则和不同频率对加筋布局的影响,在第一阶固有频率内都可用此种算法优化。 相似文献
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齿轮和轴承是机械设备中重要的部件,它的健康状况直接影响着机械设备的运行状态。研究粒子滤波对齿轮箱的振动信号进行降噪处理,需要知道信号的特性和噪声的统计特性。针对此,先对齿轮箱的齿轮进行振动分析,建立振动模型,而后再研究粒子数算法,对振动信号进行EMD分解,把分解的第一个IMF分量和残余分量进行重构,组建AR模型,经AR模型系数作为粒子滤波状态方程的系数。最后采用小波变换阈值降噪思想,把分解提出的噪声信号放到粒子滤波观测方程中,对信号进行降噪处理。 相似文献
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搭建了基于布里渊光时域分析(BOTDA)的海底电缆(海缆)振动信号监测模拟实验系统,通过实验获得了锚砸、冲刷、摩擦3种工况下的海缆振动信号.针对振动信号含有大量噪声,提出TSA-VMD-MPE降噪方法.利用被囊群算法(Tunicate Swarm Algorithm,TSA)优化变分模态分解(Variational Mode Decomposition,VMD),获取VMD分解层数与惩罚因子的最优值,对振动信号分解获得本征模态函数(Intrinsic Mode Functions,IMF)分量;利用IMF与原始信号的相关性及IMF的方差贡献率联合来确定IMF的多尺度排列熵(Multi-Scale Permutation Entropy,MPE)阈值,对振动实验信号进行降噪.实验结果表明:所提降噪算法使3种海缆振动信号信噪比平均提高了12.0296 dB;将提出的MPE阈值方法应用于EEMD与CEEMD算法也获得了良好的降噪效果. 相似文献
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《Mechatronics》2023
An over-determined multi-channel Fx-Newton algorithm is proposed for active control of structural vibration. The theoretical principle of this algorithm is first derived in the frequency domain and the implementation of the algorithm is then introduced in the time domain. Analytical results show that the rate of convergence of this algorithm is close to that of the Fx-Newton algorithm, and faster than that of the Fx-LMS algorithm. Experiments are also conducted on a raft mounted in a cylindrical shell to test the effects of active-passive vibration isolation with the Fx-Newton algorithm and the proposed over-determined Fx-Newton algorithm. The effects of attenuation of both algorithms are also evaluated on the sinusoids in the radiated noise. The results reveal that at some frequencies where the sinusoids are not suppressed by the Fx-Newton algorithm, the over-determined Fx-Newton algorithm, however, can effectively suppress their presence both in the vibration of the base plate and in the normal vibration of the cylindrical shell. Hence the over-determined Fx-Newton algorithm has excellent effect of global vibration control, and can well attenuate the sinusoids in the noise radiated by the cylindrical shell. 相似文献
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Due to the demand for higher accuracy and lower acoustic noise levels, there is a growing interest for active vibration suppression in industrial application. Many control concepts have been proposed in this field that are suited to introduce damping in systems with a large number of modes. However, tuning is often focussed on reduction of one dominant mode. Such control approaches are less transparent when several dominant modes are involved. A combined loop-shaping and root-locus tuning approach is proposed to reduce several dominant modes with low-order controllers. The tuning approach is experimentally evaluated on a vibrating plate using piezo's for both sensing and actuating. Based on the given tuning rules and tradeoffs, a single-input-single-output (SISO) feed-back controller is designed and implemented. This low authority control approach shows that besides local performance, the global damping of the plate is also improved, which consequently results in reduction of vibration levels over the whole plate for a broad range of frequencies. As a results, acoustic noise radiation is reduced significantly. 相似文献