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。当前文献中提供的高应变率载荷下的各种性能数据的准确性似乎值得怀疑。基于不确定数据的强度和结构分析的可靠性最低。本研究主要在材料的单调拉伸试验和断裂韧性试验范围内，对载荷和应变的测量程序进行了研究。特别是，向使用任何测试机器在宽温度范围内测量任何材料的任何人展示了如何测量机械性能。此外，如何准确测量也为没有专业知识的试验机操作员提供了简单的标准。 具体来说，作为钢材和有色金属的模型材料，使用了 IF 钢和 6000 系列铝合金。这两种合金作为我国安全性要求最高的机械结构，已广泛应用于汽车的车身和保险杠。这些材料在测试时已经明确了测试条件和准确性问题。利用涵盖宽温度范围和静态与高速条件之间的速率范围的材料的有效且准确的冲击性能数据，在宽应变速率范围内检查了长期以来备受争议的金属材料塑性变形冲击载荷下的本构方程。材料特性的应变率依赖性和应变率历史效应也已从理论上重新排列和研究。此外，该研究领域不仅提供了对运输机械冲击安全性和可靠性保证有实际贡献的材料试验方法和试验数据，而且有助于对材料变形行为进行基础解释，是20世纪学术界的总结。较少的

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