Realisation of 3D In-situ Assessment of Local Crack Driving Forces via Ultra-high Resolution Synchrotron Xray CT

运输机械的冲击安全性在很大程度上取决于材料本身。近年来，由于机器的轻量化，由于材料行为包括固有的冲击现象，因此强烈要求其评估具有不同于通常材料测试的机械考虑和专业知识。高应变率加载下的各种性能数据，这是在目前的文献中，似乎是值得怀疑的准确性。基于不确定数据的强度和结构分析给出的可靠性最低。本文主要针对材料的单调拉伸试验和断裂韧性试验，对载荷和应变的测量方法进行了研究。特别是，如何测量机械性能显示为任何人使用任何试验机在很宽的温度范围内的任何材料。此外，如何准确测量显示为没有专业知识的试验机操作员的简单标准的形式。 关于我们 具体地说，作为钢和有色金属的模型材料，使用IF钢和6000系列铝合金。这两种合金已被广泛应用于我国对安全性要求最高的汽车车身和保险杠等机械结构件。在对这些材料进行检测时，已阐明了检测条件和准确度问题。使用有效和准确的冲击性能数据的材料，其中包括广泛的温度和速率之间的静态和高速条件下，冲击载荷下的本构方程的金属材料的塑性变形，这一直是有争议的问题很长一段时间，已检查了宽的应变率范围。材料性能的应变率依赖性和应变率历史效应也被重新安排和理论研究。此外，这一研究领域在世纪内得到了学术上的总结，不仅为运输机械的冲击安全性和可靠性保证提供了具有实际意义的材料试验方法和试验数据，而且有助于从根本上解释材料的变形行为<th>。少

Impact safety of transport machines strongly depends on materials themselves. Recently, due to light-weightening of machines, since materials behaviors include inherent impact phenomena, it is strongly required for their evaluation to have mechanical consideration and expertise different from usual materials tests. Various properties data under high strain rate loading, which are available in the current literature, seem to be doubtful in its accuracy. Strength and structural analyses based on uncertain data give the least reliability. In the present study, mainly within the range of monotonic tensile test and fracture toughness test of materials, it has been investigated on the measuring procedures of load and strain. Especially, how to measure mechanical properties is shown for anyone using any testing machines for any materials over a wide temperature range. Also, how to measure accurately is shown as forms of easy standards for operators of testing machines without expertise.Concre … More tely speaking, as model materials for steels and non-ferrous metals, IF steels and 6000-series aluminum alloys were used. These two alloys have been extensively used for bodies and bumpers of automobiles in which the highest safety is required in our country as mechanical structures. Testing conditions and issues on accuracy have been clarified when these materials are tested. Using valid and accurate impact property data for the materials which cover wide ranges of temperature and rate between static and high speed conditions, constitutive equations under impact loading for plastic deformation of metallic materials, which have been matters of controversy for a long time, has been checked for a wide strain rate range. Strain-rate dependency of materials properties and strain rate history effects have been also re-arranged and investigated theoretically. In addition, not only providing materials test methods and test data which can contribute practically to impact safety of transport machines and reliability assurance, but also helping fundamental interpretation of materials deformation behaviors, this research area has been summed up academically within the 20^<th> century. Less