This study successfully deals with the inhomogeneous dimension problem of load separation assumption, which is the theoretical basis of the normalization method. According to the dimensionless load separation principl...This study successfully deals with the inhomogeneous dimension problem of load separation assumption, which is the theoretical basis of the normalization method. According to the dimensionless load separation principle, the normalization method has been improved by intro- ducing a forcible blunting correction. With the improved normalization method, the J-resistance curves of five different metallic materials of CT and SEB specimens are estimated. The forcible blunting correction of initial crack size plays an important role in the J-resistance curve estima- tion, which is closely related to the strain hardening level of material. The higher level of strain hardening leads to a greater difference in JQ determined by different slopes of the blunting line. If the blunting line coefficient recommended by ASTM E1820-11 is used in the improved nor- realization method, it will lead to greater fracture resistance than that processed by the blunting line coefficient recommended by ISO 12135-2002. Therefore, the influence of the blunting line on the determination of JQ must be taken into full account in the fracture toughness assessment of metallic materials.展开更多
伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环...伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环小试样,提出应用该类小尺寸试样获取材料延性断裂韧度的、基于量纲一载荷分离理论的规则化测试方法。分别采用C形环小试样和传统紧凑拉伸型(Compact tension,CT)大试样完成转子材料26Ni Cr Mo V11-5钢和压力容器材料A508-Ⅲ钢的J阻力曲线试验,讨论C形环小试样厚度、初始裂纹长度对试验结果的影响。结果表明,试样厚度和初始裂纹长度对C形环的J阻力曲线测试结果影响有限,但C形环试样裂尖具有更高的约束水平,由C形环试样得到的J阻力曲线明显低于CT试样的结果。展开更多
基金supported by the National Natural Science Foundation of China(Nos.11472228 and 11202174)the Sichuan Provincial Youth Science and Technology Innovation Team(No.2013TD0004)
文摘This study successfully deals with the inhomogeneous dimension problem of load separation assumption, which is the theoretical basis of the normalization method. According to the dimensionless load separation principle, the normalization method has been improved by intro- ducing a forcible blunting correction. With the improved normalization method, the J-resistance curves of five different metallic materials of CT and SEB specimens are estimated. The forcible blunting correction of initial crack size plays an important role in the J-resistance curve estima- tion, which is closely related to the strain hardening level of material. The higher level of strain hardening leads to a greater difference in JQ determined by different slopes of the blunting line. If the blunting line coefficient recommended by ASTM E1820-11 is used in the improved nor- realization method, it will lead to greater fracture resistance than that processed by the blunting line coefficient recommended by ISO 12135-2002. Therefore, the influence of the blunting line on the determination of JQ must be taken into full account in the fracture toughness assessment of metallic materials.
文摘伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环小试样,提出应用该类小尺寸试样获取材料延性断裂韧度的、基于量纲一载荷分离理论的规则化测试方法。分别采用C形环小试样和传统紧凑拉伸型(Compact tension,CT)大试样完成转子材料26Ni Cr Mo V11-5钢和压力容器材料A508-Ⅲ钢的J阻力曲线试验,讨论C形环小试样厚度、初始裂纹长度对试验结果的影响。结果表明,试样厚度和初始裂纹长度对C形环的J阻力曲线测试结果影响有限,但C形环试样裂尖具有更高的约束水平,由C形环试样得到的J阻力曲线明显低于CT试样的结果。
