Ti-C纤维金属层压板自由振动试验和数值分析

Tests and numerical analyses on free vibration of Ti-C fiber metal laminates

为研究由钛合金和碳纤维增强复合材料交替铺设而成的Ti-C纤维金属层压板(FMLs)的制备及自由振动,首先,使用有限元分析软件MSC.PATRAN/NASTRAN对不同尺寸Ti-C FMLs的自由振动进行了二维有限元建模计算,确定了尺寸效应对FMLs固有频率的影响;然后,采用电磁激振器和非接触式激光扫描仪进行自由振动试验,比较了数值仿真结果和试验结果;最后,计算了相同尺寸的纯碳纤维复合材料层压板和不同钛合金层压板层数的Ti-C FMLs的固有频率,研究了钛合金层压板层数对FMLs固有频率的影响。结果显示:试件的尺寸越小,固有频率的计算误差越大,即当结构面内尺寸相对于厚度的倍数较小时,模型的计算误差大;数值仿真结果和试验结果总体吻合较好,有限元模型有效;FMLs的固有频率随着钛合金层压板层数的增加而减少。所得结论可为提高Ti-C FMLs自由振动的可设计性提供参考。

In order to investigate the manufacture and free vibration of Ti-C fiber metal laminates （FMLs）which were prepared by alternated stacking arrangements of titanium alloy and carbon fiber reinforced plastics,the free vi-bration of Ti-C FMLs with different sizes were 2D finite element modeled and calculated using finite element analyses software MSC.PATRAN/NASTRAN firstly,and the influences of size effect on natural frequencies of FMLs were studied.Then,electromagnetic vibration exciter and non-contact laser scanner were used to conduct the free vibra-tion tests,and the numerical simulated results were compared the testing results.Finally,the natural frequencies of pure carbon fiber composite laminates and Ti-C FMLs with different number of layers for titanium alloy laminates with the same size were calculated,and the effects of number of layers for titanium alloy laminates on natural fre-quencies of FMLs were investigated.The results show that the smaller the specimen size is,the bigger the calcula-tion error of natural frequency is,namely,when the multiple of in-plane size to thickness of structure is relatively small,the calculation error of model is large.Over all,the numerical simulated results coincide with testing results preferably,and the finite element model is valid.The natural frequencies of FMLs decrease with the increase for number of layers for titanium alloy laminates.The conclusions obtained can provide reference to improve the design ability for free vibration of Ti-C FMLs.