基于压缩耗能假设的黏弹性夹芯梁的横向振动

Transverse vibration of viscoelastic sandwich beams based on the compression dissipating energy assumption

建立了一种新的有限元模型用于研究三层黏弹夹芯梁的横向振动。该模型第一层为约束层,中间层为黏弹性层,第三层为基梁层。将约束层和基梁层视作欧拉-伯努利(Euler-Bernoulli)梁,假定黏弹性层承受横向拉压变形。拉压应变来源于约束层和基梁层的横向相对运动,并且黏弹性层的横向位移被假定为约束层和基梁层位移之间的线性插值。为了验证该有限元模型的有效性,将其与实验结果和几种解析模型进行了对比,结果证明该有限元模型对夹芯梁结构固有频率的预测具有良好的精度,但对损耗因子的预测精度上有待提高。

A new finite element model was developed for analyzing the transverse vibration of three-layer viscoelastic sandwich beams.The first layer is the constraining layer,the mid-layer is the viscoelastic core and the third layer is the base beam.The constraining layer and the beam were treated as the Euler-Bernoulli beam.The viscoelastic core was assumed to withstand the tension and compression in the transverse vibration.The compressive strain of the viscoelastic layer comes from the relative vibration of the constraining layer and the base beam,and the displacement of the viscoelastic layer was assumed to be a linear interpolation of the displacements between the constrained layer and the beam.The results by the present finite element model were compared with the experimental results as well as the results by several analytical models to verify its validity.The results show that the finite element model can predict the resonant frequency accurately,but the prediction accuracy of the loss factor needs to be improved on.