泡沫夹层结构力学性能的非线性有限元分析

Analysis for Mechanical Properties of Foam Cored Sandwich Based on Nonlinear FEM

泡沫夹层结构因其较高的比刚度及比强度,在各领域得到广泛应用。但由于泡沫在受力过程中呈现较强的非线性,且相对其它常用材料强度较小,需对泡沫进行材料的非线性分析,才能更准确地判断泡沫夹层结构在应用中所体现的力学性能。本文根据泡沫材料呈现的相关性能,定义了该材料的非线性本构关系,并利用MSC.Marc二次开发用户子程序接口将该本构关系写入,而且引入了针对泡沫材料的三参数广义强度准则,建立了泡沫材料的非线性有限元计算模型。通过铝面板泡沫夹层结构的平拉、平压、剪切实例分析并结合其它分析方法与实验结果进行比较,论证了该泡沫材料非线性有限元模型的准确性,同时证实了广义强度准则在泡沫材料上的适用性,为泡沫夹层结构研究与应用提供了依据。

Because of the high stiffness ratio and strength ratio, the foam cored sandwich is used extensively in many fields. But its nonlinear mechanical properties and relative small strength call for nonlinear analysis, so that the mechanical properties can be predicted better. Based on the provided mechanical property data of the given foam, the nonlinear constitute for this foam was defined by using a user subroutine of MSC. Marc secondary development, and the generalized failure criteria was also introduced to this model to form the nonlinear analysis model in FEM. An example of foam-cored sandwich aluminum panels was calculated. Through the comparison with the experimental and analytical results, it demonstrates the accuracy of this nonlinear material finite element model, and the generalized failure criteria＇s applicability in this foam is also confirmed. This method can be used for reference in the research and application of sandwich structure.