共固化补片预修补铝板的阻尼和疲劳寿命研究

制备了黏弹阻尼层共固化复合材料补片,对固支的薄铝板应力集中区域进行预修补,利用基于频域的半功率带宽法测试了修补前后的结构阻尼比.建立有限元模型,采用滞后阻尼的假定计算了组合结构的等效阻尼比,对比实验值验证了该模型.采用基于功率谱密度的频域分析方法估算了结构随机振动疲劳寿命.考察了阻尼层厚度、补片长度和纤维层层数对结构等效阻尼比和随机振动疲劳寿命的影响.研究结果表明制备的黏弹阻尼层共固化复合材料补片可以提高薄壁结构的阻尼效果,并可以提高修补件的振动疲劳寿命.

Damping and fatigue life analysis of aluminum square plate pre-patched by cocured composites

The stress concentration region of the clamped aluminum square plate was prepatched by the cocured composites with an embedded viscoelastic layer,the structural damping ratio was tested by the half-power bandwidth method. The finite element model was established to calculate the equivalent modal damping ratios of composite structures. And the results were verified by the test. Based on the information of the power spectral density in frequency domain,the random vibration fatigue life of structures was estimated. The effects of damping layer thickness,length of the patch and the layers of the fiber on the equivalent damping ratio of the structure and random vibration fatigue life had also been studied. The results showed that the prepared composites with an embedded viscoelastic layer can improve the damping and the vibration fatigue life of the thin-walled structures.