摘要随着开发海洋资源日益重要，钢/聚氨酯夹层板材料的应用越来越广泛。本文基 于有限元软件 ANSYS/LS-DYNA 对霍普金森压杆(SHPB)试验技术进行仿真，研究了 高应变率下钢/聚氨酯夹层结构的动态压缩力学性能。本文采用经典二波法和三波法 处理实验结果，得到了钢/聚氨酯夹层板的动态压缩应力应变曲线。对相同厚度比的 钢/聚氨酯夹层板在不同应变率下的动态压缩力学性能的分析表明，钢/聚氨酯夹层结 构对应变率较为敏感，其屈服强度随应变率的增大而增大。通过实验结果的分析，得 到提高该材料抗冲击能力的方法，采用较大的厚度比或使较厚的钢面板承受冲击。基 于 Johnson-Cook 模型，建立了适用于不同厚度比的钢/聚氨酯夹层结构的动态本构关 系模型，并对多组实验结果进行拟合，确定了模型中的参数。该模型能描述不同厚度 比的钢/聚氨酯夹层结构在高应变率下的应力应变关系，具有较高的精度。在厚度比 较小时，建立了基于 ZWT 模型的动态本构关系，该本构方程在厚度比较小时的精度 高于 Johnson-Cook 模型但其在厚度比上不具一般性。79825
毕业论文关键词：夹层结构；SHPB；本构关系模型；动态压缩力学性能；厚度比
Abstract With the development of marine resources, the application of steel / polyurethane sandwich plate material is more and more widely。 Dynamic compression experiments of steel / polyurethane sandwich structure under the high strain rate is proposed based on the simulation of split Hopkinson pressure bar (SHPB) experimental tests by the finite element software ANSYS / LS-DYNA。 Dynamic constitutive model of steel / polyurethane sandwich is established by using classic two-wave and three-wave data processing method。 Analysis of dynamic compressive mechanical properties of steel / polyurethane sandwich panels with the same thickness ratio under different strain rates shows, steel / polyurethane sandwich structure is sensitive to the strain rate, its yield strength increases with the increase of strain rate。 The method to improve the impact resistance of the material which is choosing a larger thickness ratio or making a thicker steel plate under impact is obtained by analyzing the results。 Dynamic constitutive model for steel / polyurethane sandwich structure is established based on Johnson-Cook constitutive model, which is suitable for different thickness ratios。 The model is accurate to descript the stress-strain curve of steel / polyurethane sandwich structure with different thickness ratio under high strain rate, which is effective。 Based on the ZWT constitutive model, the dynamic constitutive relation is established on the small thickness ratios, its accuracy of the constitutive equation on the small thickness ratios is higher than that of the Johnson-Cook constitutive model but is not suitable for all thickness ratios。
Keywords: Sandwich structure; SHPB; constitutive model; dynamic compressive mechanics properties; thickness ratio
目录
第一章 绪论 1
1。1 课题研究的意义 1
1。3 课题研究的主要内容和方法 4
第二章 SHPB 实验技术的数值仿真 6
2。1 SHPB 实验技术 6
2。2 试样设计 7
2。3 子弹与波导杆设计 9
2。4 子弹速度与应变率设计 9
2。5 ANSYS/LS-DYNA 仿真 10
2。5。1 建立有限元模型 LS-DYNA钢/聚氨酯夹层板动态压缩力学性能仿真分析:http://www.youerw.com/wuli/lunwen_92485.html