摘要由于冲击和振动给我们带来许多不便和危害，因此我们需要对此情况进行预防，其主要途径之一就是使用缓冲材料来减缓冲击和振动。本次仿真是用一圆柱形弹体以一定初速度分别撞击蜂窝铝、泡沫铝和混凝土等缓冲材料，并保证弹体最大加速度不小于2000g（g为重力加速度）以及较长的脉冲宽度，从中选出符合要求的缓冲材料。针对这一问题，采用有限元法，在SolidWorks中建立材料的几何模型，利用HyperMesh建立有限元模型。仿真中定义了弹体与材料的侵彻接触算法，以弹体初速度为载荷，以固定材料侧面为边界条件，利用LS-DYNA软件进行有限元求解，得到侵彻过程中的加速度、速度等数据，发现混凝土的弹体最大加速度远大于蜂窝铝和泡沫铝的，而弹体加速度脉宽最长的是泡沫铝的，这可为今后的选材提供参考。28473
关键字  缓冲材料，有限元法，冲击，最大加速度，弹体
毕业论文设计说明书外文摘要
Title    Modeling and analysis of impact property  for cushioning materials           
Abstract
Impact and vibration always bring us troubles and damage, so we should do something to prevent. The one of main ways is using cushioning materials to reduce the damage. In this simulation, cushioning materials, including aluminum honeycomb, aluminum foam and concrete, are impacted by a cylindrical bullet with initial velocity. Meanwhile, it's ensured that the maximum acceleration of bullet is greater than 2000g(g is acceleration of gravity) and that pulse width is obtained as long as possible. In the end, the satisfactory material can be found. About this problem, the finite element method is used. The geometric models are created with SolidWorks and the finite element models are created with HyperMesh. When modeling, it should be done defining the erosion contact algorithm about bullet and materials, using initial velocity of bullet as load, and using constraint as boundary condition. LS-DYNA is used to solve the finite element models, and then data of acceleration and velocity in penetration are obtained.It's found that maximum acceleration of bullet in simulation about concrete is much bigger than aluminum honeycomb's and aluminum foam's. However, the acceleration pulse width of bullet in simulation about aluminum foam is longest, which can be a reference for choosing cushioning materials.
Keywords  cushioning materials  finite element method  impact    maximum acceleration  bullet
 目   录
1  绪论 1
1.1  选题的背景和意义 1
1.2  国内外研究现状 1
1.2.1  缓冲材料 1
1.2.2  有限元法 3
1.3  主要研究内容 6
2  缓冲材料及弹体的网格划分 7
2.1  缓冲材料类型 7
2.1.1  蜂窝铝 7
2.1.2  泡沫铝 8
2.1.3  混凝土10
2.2  缓冲材料及弹体的网格模型11
2.2.1  蜂窝铝网格模型12
2.2.2  泡沫铝网格模型13
2.2.3  混凝土网格模型14
2.2.4  弹体网格模型15
2.3  本章小结15
3  缓冲材料冲击特性有限元建模16
3.1  侵彻问题分析方法16
3.1.1  经验公式法16
3.1.2  理论解析法17
3.1.3  数值模拟法18
3.2  单元属性和材料参数的设置18
3.2.1  蜂窝铝参数设置18
3.2.2  泡沫铝参数设置19
3.2.3  混凝土参数设置19
3.2.4  弹体参数设置20
3.3  边界条件和载荷建模21
3.4  定义接触关系23
3.5  设置计算参数及输出文件23
3.5.1  设置计算参数23
3.5.2  设置输出文件26
3.6  本章小结26 SolidWorks+LS-DYNA缓冲材料冲击特性建模与分析:http://www.youerw.com/zidonghua/lunwen_23323.html