The strain dependent characteristics of hard coatings make the vibration analysis of hard-coated composite structure become a challenging task. In this study, the modeling and the analysis method of a hard-coated composite beam was developed considering the strain dependent characteristics of coating material. Firstly, based on analyzing the properties of hard-coating material, a high order polynomial was adopted to characterize the strain dependent characteristics of coating materials. Then, the analytical model of a hard-coated composite beam was created by the energy method. Next, using the numerical method to solve the vibration response and the resonance frequencies of the composite beam, a specific calculation flow was also proposed. Finally,a cantilever beam coated with Mg O + Al2_O_3 hard coating was chosen as the study case; under different excitation levels, the resonance region responses and the resonance frequencies of the composite beam were calculated using the proposed method. The calculation results were compared with the experiment and the linear calculation, and the correctness of the created model was verified. The study shows that compared with the general linear calculation, the proposed method can still maintain an acceptable precision when the excitation level is larger.
在固定硬涂层形状的前提下寻找最佳的涂敷位置是工程化实施硬涂层阻尼减振的迫切需求。以硬涂层薄板为例,研究实现上述硬涂层阻尼优化的方法。针对局部涂敷硬涂层的薄板结构完成了有限元建模,并利用修正模态应变能法确定了涂层复合结构的模态损耗因子。以获得单阶次或者多阶次最大模态损耗因子为目标,以涂层位置为设计变量描述了该硬涂层薄板阻尼优化模型。提出利用多种群遗传算法求解该优化问题的方法。以单面局部涂敷Ni Cr Al Co Y+YSZ硬涂层材料的悬臂板为例进行了实例研究,基于所创建的优化模型和优化方法,在薄板上实施了硬涂层涂敷位置的优化,并用实验验证了硬涂层板阻尼优化结果的合理性。
