金字塔型点阵材料夹芯板抗爆性能仿真与优化

Simulation and optimization for blast-resistant performances of pyramidal lattice cored sandwich panels

金属点阵材料夹芯板因其轻质、高比强度、高比刚度以及多功能和良好的可设计性等优势在工程防护领域应用潜力巨大。基于动力显式有限元法,仿真研究了金字塔型金属点阵材料夹芯板在爆炸载荷下的动态响应,并进行了针对其抗爆性能的多目标优化;建立了包含实体单元芯体的夹芯板详细有限元模型,并提出了采用梁单元芯体的简化模型;通过与文献实验结果对比验证了模型的有效性和准确性;在此基础上,以面比吸能和背板最大变形量为评价指标,采用单一变量法分析了芯体关键几何参数对夹芯板抗爆性能的影响;以关键几何参数为变量,利用响应面模型和遗传算法对夹芯板进行了抗爆性能多目标优化;并考虑爆炸当量不确定性,完成了夹芯板抗爆性能可靠性优化。结果表明,梁单元芯体简化模型可大幅度提高仿真计算效率,为夹芯板抗爆性能优化提供便利;芯体关键几何参数对金字塔型点阵夹芯板抗爆性能影响很大;多目标优化和可靠性优化能够提高金字塔型点阵夹芯板的综合抗爆性能和可靠性。

Metal lattice sandwich structures have great potential in the field of engineering protection owing to its lightweight,high strength,high specific stiffness characteristics and excellent multifunctional applications and designablity.In this work,based on the explicit finite element(FE)method,the dynamic responses of the pyramidal metallic lattice sandwich panels(PLSPs)under blast loading were simulated,and the multi-objective optimization for their blast-resistant performances was carried out.Firstly,a detailed FE model of the sandwich panel containing a solid-element model of the lattice core was established,and a simplified beam-element model was proposed.Secondly,the effectiveness and accuracy of the models were verified by referring to the experimental results in literature.By using the simplified model,the influences of key geometric parameters on the blast-resistant performances of the sandwich panels were analyzed based on the single variable method in terms of areal specific energy absorption(ASEA)and maximum back face deflection(MaxD).Then,based on radial basis function(RBF)response surface models and by using the non-dominated sorting genetic algorithm(NSGA-II),multi-objective design optimizations(MDO)were conducted to maximize ASEA and minimize MaxD with the key geometric parameters as design variables.Lastly,the reliability-based optimization of the blast-resistant performances of the sandwich panels was performed considering blast load uncertainty.The results show that using a simplified beam-element model of the lattice core greatly improves simulation efficiency and facilitates the optimization process.Key geometric parameters have great influences on the blast-resistant performances of the PLSPs.MDO and reliability-based optimization of PLSPs could improve their comprehensive blast-resistant performances and reliability.