Modelling and FEA-simulation of the anisotropic damping of thermoplastic composites
Modelling and FEA-simulation of the anisotropic damping of thermoplastic composites
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DOI：
10.12989/aas.2016.3.3.331
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
M. Klaerner;M. Wuehrl;L. Kroll;S. Marburg
中科院分区：
文献类型：
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作者：
M. Klaerner;M. Wuehrl;L. Kroll;S. Marburg
用于航空和航天飞行器的硬纤维和轻纤维增强复合材料具有高声发射的特点。因此，阻尼特性对整个结构和声学工程至关重要。粘性阻尼是一种已建立的合理的线性耗散模型。通常，假定它在所有模态上都是各向同性和恒定的。对于各向异性材料，它取决于纤维取向以及材料的弹性和热性能。为了描述纤维增强塑料（frp）的正交各向异性行为，ADAMS和BACON从1973年开始在经典层压理论的基础上建立了单向纤维增强塑料（frp）的模型。他们的方法包括三个阻尼系数-纤维方向的纵向阻尼，纤维横向阻尼和基于剪切的耗散。然后逐层累积层合板的阻尼，包括各向异性刚度。到目前为止，该模型主要应用于热固性基体材料。本文通过测量悬臂梁的自由振动，对不同热塑性玻璃钢的角铺层和交叉铺层进行了试验参数估计。结果显示了ADAMS/BACON阻尼准则的潜力和局限性。此外，还提出了模拟各向异性阻尼的可能性。采用标准有限元软件实现，研究了边界条件对薄壁玻璃钢构件阻尼性能的影响，并对薄壁玻璃钢构件的辐射声功率进行了数值计算。
Stiff and light fibre reinforced composites as used in air- and space-craft applications tend to high sound emission. Therefore, the damping properties are essential for the entire structural and acoustic engineering. Viscous damping is an established and reasonably linear model of the dissipation behaviour. Commonly, it is assumed to be isotropic and constant over all modes. For anisotropic materials it depends on the fibre orientation as well as the elastic and thermal material properties. To portray the orthogonal anisotropic behaviour, a model for unidirectional fibre reinforced plastics (frp) has been developed based on the classical laminate theory by ADAMS and BACON starting in 1973. Their approach includes three damping coefficients - for longitudinal damping in fibre direction, damping transversal to the fibres and shear based dissipation. The damping of a laminate is then accumulated layer wise including the anisotropic stiffness. So far, the model has been applied mainly to thermoset matrix materials. In this study, an experimental parameter estimation for different thermoplastic frp with angle ply and cross ply layups was carried out by measuring free vibrations of cantilever beams. The results show potential and limits of the ADAMS/BACON damping criterion. In addition, a possibility of modelling the anisotropic damping is shown. The implementation in standard FEA software is used to study the influence of boundary conditions on the damping properties and numerically estimate the radiated sound power of thin-walled frp parts.