基于复合耗能假设的黏弹夹芯梁振动的有限元分析

建立了一种新的有限元模型用于研究黏弹夹芯梁的振动和阻尼特性。该模型同时考虑了黏弹性层的剪切和压缩阻尼。建模时将约束层和基梁层视作欧拉-伯努利(Euler-Bernoulli)梁,假定中间黏弹性层同时承受纵向剪切和横向压缩变形以耗散振动能量。应用该模型研究了不同边界条件和几何参数的黏弹夹芯梁结构的振动和阻尼特性。通过与精确解析法及其它常用数值法的对比,结果证明该模型具有良好的精度和适用性,在对夹芯梁结构固有频率和损耗因子的预测中,其精度要高于常规的几种数值模型。最后通过实验结果进一步地验证了该有限元模型的正确性。

Finite element analysis for vibration of a viscoelastic sandwich beam based on composite energy dissipation hypothesis

A new finite element (FE) model was established to study vibration and damping characteristics of a viscoelastic sandwich beam considering shear and compressive damping of viscoelastic layer.The constraint layer and base beam layer of a viscoelastic sandwich beam were regarded as an Euler-Bernoulli one during modeling.Its intermediate viscoelastic layer was assumed to be subjected to both longitudinal shear and transverse compression deformations for the purpose of dissipating vibrational energy.Vibration and damping characteristics of the beam with different boundary conditions and geometric parameters were studied using this FE model.Compared with the results of the precise analytical method and other commonly used numerical ones,it was shown that the proposed FE model has good accuracy and applicability;in predicting natural frequency and loss factor for sandwich beam structures,its accuracy is higher than those of several conventional numerical models.Finally,the correctness of this FE model was further verified with the test results.