Elasto-Plastic Test of Q235 Steel Bending Beam With Cracking Resistance  

作　　者：WANG Li-min FENG Ying CHEN Fan-xiu WANG Hai-ying WANG Dong-xu 

机构地区：[1]Science School,Qingdao Technological University [2]Institute of Mechanics,Chinese Academy of Sciences

出　　处：《Journal of Iron and Steel Research International》2013年第11期57-66,共10页

基　　金：Sponsored by National Natural Science Foundation of China(51008166,11172311,10272068)

摘　　要：More than 30 bending beams with rectangular cross-section and different thicknesses and heights were pre- pared from Q295 steel. The specimen dimensions were about 240 mm （length） × 60 mm （height） ×70 mm （thick ness）. Flaws were cut along its middle line with a wire cutter, with lengths ranging from 6 to 35 mm. Each specimen was tested with three-point bend loading, and a process curve was obtained between load and the displacement of the loading point, in order to analyze the fracture process when opening the crack. A deformation near the prefabricated crack was observed in the testing period, and the variation of the fracture characteristic parameters was analyzed for different sizes. For a comprehensive understanding of carbon steel fracture resistance behavior, its elasticity and plas- ticity were established by determining its Young＇s modulus and Poisson＇s ratio with an optical strain gauge. This gauge was also used for the loading process test. It was found that the fracture toughness varied with the dimensions, and the toughness of the elastic limit loading was almost constant. Using the relationship of crack resistance stress intensity factor and fracture criterion, the bearing capacity of the material structure could be estimated, which shows a good agreement with the experimental test data.More than 30 bending beams with rectangular cross-section and different thicknesses and heights were pre- pared from Q295 steel. The specimen dimensions were about 240 mm （length） × 60 mm （height） ×70 mm （thick ness）. Flaws were cut along its middle line with a wire cutter, with lengths ranging from 6 to 35 mm. Each specimen was tested with three-point bend loading, and a process curve was obtained between load and the displacement of the loading point, in order to analyze the fracture process when opening the crack. A deformation near the prefabricated crack was observed in the testing period, and the variation of the fracture characteristic parameters was analyzed for different sizes. For a comprehensive understanding of carbon steel fracture resistance behavior, its elasticity and plas- ticity were established by determining its Young＇s modulus and Poisson＇s ratio with an optical strain gauge. This gauge was also used for the loading process test. It was found that the fracture toughness varied with the dimensions, and the toughness of the elastic limit loading was almost constant. Using the relationship of crack resistance stress intensity factor and fracture criterion, the bearing capacity of the material structure could be estimated, which shows a good agreement with the experimental test data.

关 键 词：elasto-plastic property fracture toughness elastic limit loading bearing capacity cracking resistance Q235 steel bending beam 

分 类 号：TG142.15[一般工业技术—材料科学与工程]