涂覆聚脲涂层的纤维增强树脂基复合材料板减振抗冲击性能研究

Research on vibration and impact-resistant performances of fiber reinforced resin matrix composite plates with polyurea coating

本文分别建立了用于振动和冲击特性分析的涂覆聚脲涂层的纤维增强树脂基复合材料板的两类动力学模型,并对涂层-复合材料板结构的减振和抗冲击性能同时进行了量化评估.采用一阶剪切变形理论表示结构系统的位移场,通过Rayleigh-Ritz法求解固有频率,并通过振型叠加法获得脉冲激励下的振动响应,进一步通过傅里叶变换和卷积运算推导获得了评价抗振性能的关键指标"动刚度";另外,在考虑低速冲击造成的结构变形基础上,建立了等效的二自由度弹簧-质量模型来描述其动态冲击过程与接触力的变化.同时,使用线性化赫兹接触理论获取冲击接触力,并通过Runge-Kutta法求解冲击响应,进而获得了评价抗冲击性能的关键数据"载荷-位移曲线".最后,以有、无聚脲涂层的T300碳纤维/环氧树脂基复合材料板为研究对象,搭建了振动与冲击一体化测试系统,获得了有、无涂层试件的多项动力学参数,验证了理论分析模型及其预测结果的正确性.研究结果表明,敷聚脲涂层后,复合材料板试件的前四阶动刚度最大提升了74.7%,且载荷-位移曲线上的冲击接触力和位移峰值分别下降了13.9%和13.3%,有效证明了聚脲涂层在结构减振和抗冲击性能方面发挥的积极贡献.

In this paper, two types of dynamic models for vibration and impact analyses of the fiber-reinforced resin matrix composite plates with polyurea coating are established, respectively. Also, the vibration and impact resistant performances of the coating-composite plate structures are evaluated quantitatively. For one thing, the first-order shear deformation theory is adopted to represent the displacement field of the structural system, and the natural frequency is solved by the Rayleigh-Ritz method. Meanwhile, the vibration response subjected to impulse excitation is achieved by the mode superposition method, and the key index "dynamic stiffness" for evaluating the vibration resistant performance is obtained by the Fourier transform and convolution calculation operations. For another thing, with consideration of the structural deformation affected by the low velocity impact, an equivalent twodegree-of-freedom spring-mass model is established to describe the dynamic impact process and the change of contact force.Meanwhile, the linearized Hertz contact theory is utilized to obtain the impact contact force. After the impact response is solved by the Runge-Kutta method, the key data "load-displacement curve" for evaluating impact resistant property is further obtained. Finally,by taking T300 carbon fiber/epoxy-based composite plate specimens with and without polyurea coating materials as the research objects, an integrated vibration and impact test system is set up. Several dynamic parameters of those specimens with and without coating are obtained, which validate the theoretical analysis models as well as their prediction results. The research results indicate that after the polyurea coating is applied, the first four dynamic stiffness values of the composite plate specimens are increased with the maximum rising degree of 74.7%, and the impact contact forces and displacement peak values of the load-displacement curves are reduced by 13.9% and 13.3%, respectively. Hence, the contribution of polyurea coating to the effects of vibration suppression and impact resistance of the structure system has been effectively verified.