钢材的冲击韧性对断裂韧性的影响分析(英语完全).docVIP

The Ninth International Symposium on Structural Engineering for Young Experts, August 18-21 2006, Fuzhou Xiamen, China aa Analysis on the Influence of Impact Toughness on Fracture Toughness for Structure Steel Wang Xi, Yuan-Qing Wang, Yong-Jiu Shi Department of Civil Engineering, Key Laboratory of Structural Engineering and Vibration of China Education Ministry, Tsinghua University Beijing, 100084, P.R. China ABSTRACT: Impact toughness and fracture toughness are the two important mechanical indexes of structure steel. This paper introduces the normal impact toughness index, impact absorption work, which is widely applied in the steel structure design. Also the paper describes the definitions of steel impact toughness in the standards domestic and abroad and some data in the standards are enumerated. It is introduced that there are three criterions used to judge the fracture, K criterion, J criterion and COD criterion. How to use the criterions is pointed out. At last, the correlation between impact toughness and fracture toughness is emphatically discussed based on the existing studies while some research results are enumerated. KEYWORDS: structure steel, impact toughness, fracture toughness, correlation 1. indexes used to measure the impact toughness of steel The impact toughness is an important mechanical index to measure the performance ability of steel, it reflects the plastic deformation and energy absorbing ability of steel in the three-dimensional stress state. There are two approaches to measure impact toughness, Charpy V-notch and U-notch tests, the former is widely used domestic and abroad. There are two index to measure the V-notch impact toughness, one is “Akv”, which is the absorbed energy in the impact test by the normal sample. The index has obvious physical meaning, its unit is “J”; the other is “akv”, which is the quotient derived from the Akv divided by the area at the notch section, it is merely the maths mean value of the impact work on the fr