针对对称铺设的复合材料层合薄板,用层合板的经典理论建立了相应的非线性动力学方程.采用多尺度法,导出了系统受前两阶模态间1:3 内共振及第1 阶模态主参激共振时的平均方程.采用石墨/环氧纤维复合材料层合板参数作为基础,进行数值计算,得到相应的幅频响应曲线.研究表明,系统阻尼的增大能够削弱系统的幅值,单层层合薄板厚度的微弱变化引起层合板整体拉伸刚度、弯曲刚度对应的变化,随厚度增加,整个系统偏离1:3 内共振.
A set of nonlinear dynamic differential equations was established for a symmetric composite laminate plate.The multi-scale method was used to the nonlinear equations and the average equations for the principal parametric resonanceof the first mode and the1:3 internal resonance between the first two modes were derived respectively. Numerical simulationof a graphite/epoxy composite plate was done and the corresponding amplitude-frequency response curves were obtained.Results show that increase of system damping can reduce the response amplitudes, a small change of thickness can cause ahuge change of tensile stiffness and bending stiffness of the composite laminate plate and the change of thickness can also destroyinternal resonance. Thus, the 1:3 internal resonance of the laminate plate can be shifted with thickness increasing.