聚丙烯酸酯和水性聚氨酯阻尼涂料的减振性能研究

Analysis of damping performance of acrylic resin and polyurethane coatings

若能够有效阻隔振动和噪声的传递或在其传递过程中对其能量进行快速衰减,可显著提高乘客的舒适度。将聚丙烯酸酯和水性聚氨酯涂料作为阻尼层涂覆在薄壁结构上,基于单输入单输出(SISO)模态试验方法和正弦扫频激励试验方法探究阻尼层的涂覆厚度、外界激励力频率和激励力幅值对薄壁结构动力学特性的影响规律。首先,将薄壁结构的模态测试结果与使用有限元法计算得到的结果进行对比,发现两者差值较小,验证了SISO模态试验方法的准确性。随后将SISO模态测试方法应用于测试不同涂覆材料和不同涂膜厚度后复合结构阻尼比的变化情况,揭示涂覆阻尼层后复合结构阻尼比的变化情况。试验结果表明:随着涂覆厚度的增加,复合结构的阻尼比随之增大,但不同频率下阻尼比的增加幅度并不相同。另外,对比相同涂覆厚度的阻尼层,聚丙烯酸酯阻尼涂料提供的阻尼比更加稳定。为进一步验证聚丙烯酸酯阻尼涂料的减振能力,对涂覆厚度为1.5 mm的复合结构进行10~500 Hz频率范围内的扫频激励试验。试验结果表明:聚丙烯酸酯涂料能够有效降低薄壁结构在不同激励力频率、不同激励力幅值下薄壁的动态响应幅值,快速耗散振动的能量,提高薄壁结构的稳定性。研究成果可为聚丙烯酸酯和水性聚氨酯阻尼涂料在薄壁结构振动控制中的应用提供指导。

If it can effectively block the transmission of vibration and noise or rapidly attenuate its energy during its transmission,the comfort of passengers can be significantly improved.Polyacrylate and waterborne polyurethane coatings were used as damping layers to coat the thin plate structure.Based on the single input single output(SISO)modal test method and the sinusoidal sweep excitation test method,the influence of the coating thickness of the damping layer,the frequency and amplitude of the external excitation force on the dynamic characteristics of the thin plate structure was investigated.First,the modal test results of the thin plate structure were compared with the results calculated by the finite element method,revealing minimal discrepancies and thus affirming the precision of the SISO modal test method.Then the SISO modal test method was applied to test the change of the damping ratio of the composite structure after different coating materials and different coating thickness,and the variation in the damping ratio of the composite structure after the coating damping layer was revealed.The test results show that the damping ratio of the composite structure increases with the increase of the coating thickness,but the increase of the damping ratio at different frequencies is not the same.In addition,compared with the damping layer of the same coating thickness,the damping ratio provided by polyacrylate damping coating is more stable.In order to further verify the damping capacity of polyacrylate damping coating,the sweep frequency excitation test in the frequency range of 10~500 Hz was carried out on the composite structure with a film thickness of 1.5 mm.The test results show that the polyacrylate coating can effectively reduce the dynamic response amplitude of the thin plate structure under different excitation force frequencies and different excitation force amplitudes,and can quickly dissipate the vibration energy and improve the stability of the thin plate structure.The research results can provide guidance for the application of polyacrylate and waterborne polyurethane damping coatings in vibration control of thin plate structures.