湿热环境下复合材料层合板振动与声辐射特性分析

发布时间：2018-12-28 17:25

【摘要】：研究了湿热环境中正交各向异性复合材料层合板结构受简谐激励作用的振动和声辐射特性。考虑了湿热应力和质量效应,利用一阶剪切变形理论和模态叠加法推导出四边简支层合壁板的固有频率计算公式,并采用Rayleigh积分得到其在简谐激励下的声辐射特性公式。基于湿热膨胀的等效性获得不同湿热环境下复合材料层合板的等效热膨胀系数,并进行有限元数值模拟,对理论公式进行了验证。算例结果表明,湿热环境导致复合材料层合板产生湿热应力,使得固有频率减小;单层板的振动特性对湿度和温度的变化更敏感;随着湿度和温度的增加,简谐激励作用下的复合材料层合板的振动速度响应、辐射声压级(SPL)、辐射声功率和声辐射效率曲线的波峰逐渐向低频方向移动,同时声辐射效率随之降低;低阶固有频率受湿度和温度的影响更加明显,声辐射特性曲线中低阶模态的波峰移动更显著。
[Abstract]:The vibration and acoustic radiation characteristics of orthotropic composite laminates subjected to harmonic excitation are studied. Considering the hygrothermal stress and mass effect, the formula for calculating the natural frequency of four simply supported laminated panels is derived by using the first order shear deformation theory and modal superposition method, and the formula of acoustic radiation characteristics under simple harmonic excitation is obtained by Rayleigh integral. Based on the equivalence of hygrothermal expansion, the equivalent coefficient of thermal expansion of composite laminates in different humid and thermal environments was obtained, and the finite element numerical simulation was carried out to verify the theoretical formula. The numerical results show that the hygrothermal stress of composite laminates is induced by humid and thermal environment, and the natural frequency decreases, and the vibration characteristics of single layer plates are more sensitive to the changes of humidity and temperature. With the increase of humidity and temperature, the vibration velocity response of composite laminates subjected to harmonic excitation, the wave peak of (SPL), radiation power and acoustic efficiency curve of radiation sound pressure level gradually moves to the direction of low frequency. At the same time, the efficiency of acoustic radiation decreased. The influence of humidity and temperature on the low order natural frequency is more obvious, and the peak movement of the low order mode in the acoustic radiation characteristic curve is more obvious.
【作者单位】：西北工业大学航空学院;
【基金】：国家自然科学基金(11472216)~~
【分类号】：TB33

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