泡沫铝填充Ⅰ型夹层板尺寸参数对腹板屈曲失效模式的影响分析

Analysis of buckling failure modes of composite sandwich panels filled with aluminum foam

[目的]为掌握面板间距、板厚等尺寸参数对泡沫铝填充I型夹层板腹板屈曲失效模式的影响,需揭示其在面外压缩过程中的承载特性变化规律。[方法]采用非线性有限元法模拟复合夹层板面外压缩过程,其中泡沫铝材料的力学性能参数根据试验获得,在计算模型中由各向同性crushable foam材料模型实现。通过准静态压缩试验与仿真计算结果的对比,验证所采用数值模拟方法的准确性。[结果]结果显示,随着细长比的减小,复合夹层板腹板由屈服破坏转变为塑性屈曲失效,依次经历塑性压缩、低阶屈曲等5种破坏模式;在高阶屈曲下,每当腹板生成整周期变形波,应力曲线均会出现极小值;不同细长比下复合夹层板的压缩强度均在应变为0.12附近出现,且始终维持在9.36 MPa左右。[结论]细长比是影响复合夹层板腹板屈曲失效模式的重要因素,不同细长比的复合夹层板压缩力学性能特征差异明显,在进行复合夹层板结构优化设计时应予以重视。

[Objectives]The goal of this article is to grasp the influence of panel spacing,plate thickness and other dimension parameters on the web buckling failure modes of I-type sandwich panels with aluminum foam.The change rules of its bearing characteristics during out-of-plane compression are revealed.[Methods]The nonlinear finite element method was used to simulate the out-of-plane compression process of composite sandwich panels.The mechanical properties of aluminum foam were obtained from experiments.Aluminum foam was realized using an isotropic crushable foam model in the FEM simulation.The accuracy of the numerical simulation methods used in this article was verified by comparing the quasi-static test results with the simulation results.[Results]The results show that with the decrease in the slenderness ratio,the failure modes of webs gradually transformed from material yield to plastic buckling,and five deformation modes such as plastic compression and low-order buckling appeared successively.Under high-order buckling,the stress curve will have a minimum value whenever a whole period deformation wave is generated.Under different slenderness ratios,the compressive strength of the composite sandwich panel appeared near the strain of 0.12,and was always maintained at about 9.36 MPa.[Conclusions]The slenderness ratio is an important factor affecting the web buckling failure modes of composite sandwich panels.The compression mechanical properties of composite sandwich panels with different slenderness ratios have obvious differences which require attention in structural optimization design.