Modern Impact and Penetration Mechanics
Modern Impact and Penetration Mechanics
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现代冲击和渗透力学
DOI：
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发表时间：
2021
期刊：
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通讯作者：
James Walker
中科院分区：
文献类型：
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作者：
James Walker
材料在我们周围都在运动。表1.1显示了涉及的代表性速度。影响和渗透问题是我们的主要材料。应力张量与应变张量的关系包含有关固体的刚度和强度（对剪切的电阻）。织物经历大型挠度。一路变形（材料分离）。连续的材料。米的基本方程将开发出来 - 质量，动量和能量的保护在金属中的机械系统中，动态系统的典型速度为5至6 km/s，这是空气中的声音速度的15至18倍。这些声波在现代力学中。进行材料的响应符合分析形式，或者在表中存储它涉及到影响力和渗透方面的力学问题，分析建模方法对系统响应的几何形状进行了假设，这些几何形状将问题降低到少数几个普通的差异明确或数值求解的方程式
Material is in motion all around us. Sometimes the relative motion leads to collisions, either accidental or intentional. The purpose of this book is to describe the mechanics of these collisions and the impact or penetration that follows, and to provide tools for determining the forces and deformation involved. Representative speeds of interest are shown in Table 1.1. This book is an applied mechanics text, meaning it develops the mathematical tools in physics and engineering that are required to solve impact and penetration problems. Our primary interest is in solid materials. Since impacts can lead to large forces, there will be large deformations, and so our mathematical tools and our material models will address large deformation. A big step is understanding the stress tensor – the relationship of the stress tensor to the strain tensor contains information about the stiffness and strength (resistance to shear) of solids. We will explore how metals deform, flow, and break. We will explore how yarns and fabrics undergo large deflections. Modern armors are made from metals, ceramics, fabrics, explosives, and space. Armors are interesting in that they are designed to be as light weight as possible, and during an impact event the armor material is utilized through large deflection and deformation all the way to material failure (material separation). The general framework we use is continuum mechanics. Continuum mechanics is the study of materials that can be viewed as a continuous material. This means that there is a smallest scale that it can reasonably address – on the order of tens of nanometers; otherwise atoms must be modeled. Our interest is typically in much larger scales, in macroscopic objects that are usually on the order of millimeters to meters. The basic equations of continuum mechanics will be developed – equations of conservation of mass, momentum, and energy. Then they will be applied. We will study waves in detail. All information in dynamic mechanical systems is conveyed through mechanical waves. In metals, the low pressure acoustical waves have a typical speed of 5 to 6 km/s, which is 15 to 18 times the speed of sound in air. High pressure shocks can travel faster than these acoustical waves. In modern mechanics we have a threefold approach to understanding, namely experiments, analytical modeling, and large-scale numerical simulations. As a preliminary step, basic material tests are performed and the response of materials is either fit to analytic forms or stored in tables. The material response is typically referred to as equation of state and constitutive models. These material models are then used in analytical modeling and large-scale numerical simulations. When it comes to applications to mechanics problems in impact and penetration, the analytical modeling approach makes assumptions about the geometry of the system response that reduce the problem to a handful of ordinary differential equations that are solved either explicitly or numerically. Large-scale numerical