表征小尺寸构件断裂性能的楔入法研究

项目名称： 表征小尺寸构件断裂性能的楔入法研究

项目编号： No.11202174

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 包陈

作者单位： 西南交通大学

项目金额： 26万元

中文摘要： 随着薄板、薄壁管件以及贵重金属零部件在航空航天、核反应堆、化工等工程领域的广泛应用，使得特征尺寸在几毫米的小尺寸构件的断裂性能测试需求日益凸显。然而，传统的紧凑拉伸和三点弯曲试验因其各自的局限而无法直接用于该类含裂纹小尺寸构件的断裂性能测试，目前也无其他的有效技术方案。本申请项目拟开展"表征小尺寸构件断裂性能的楔入法研究"，通过新的试样构形设计并配合楔入式加载达到试样小型化的目的，建立对应于新设计试样构形和楔入式加载的断裂性能表征参量的理论表达式，发展用于构件楔入式断裂加载中的实时裂纹长度预测的柔度法和载荷分离法测试体系，进而实现对毫米级小尺寸构件断裂性能的表征。为验证楔入法的有效性，选用若干典型工程材料开展同传统紧凑拉伸法和三点弯曲法的比对实验。研究成果对于核反应堆、飞机以及化工设备结构部件的断裂性能评定及其寿命评估具有重要意义，有利于推动实验力学在结构完整性评定中应用。

中文关键词： 断裂性能；小尺寸试样；柔度法；约束效应；疲劳裂纹扩展理论模型

英文摘要： WWith widely application of thin plate, thin-walled tube, and the components by made of precious metal in the fields of aeronautics and astronautics, nuclear reactor, and chemical industry, the demand of fracture properties determination for small components in size of a few millimeters has become increasingly prominent. However, due to the limitation of traditional compact tension and three-point bending tests, they can not be directly used for the fracture properties determination of this type of small components. Further, no other effective method can be used at present. This project will carry out a research on the wedge method to represent fracture properties for small components. By designing new specimen configuration in conjunction with wedge loading, the size of specimen may achieve the purpose of miniaturization. The theoretical expressions of the corresponding fracture parameters will be established. The test systems of compliance method and load separation method to determine the instant crack size of small components under wedge loading will be developed, then the representation of fracture properties for the small components in milli-scale is implemented. To certify the validity of the new wedge method, comparative tests on the traditional compact tension and three-point bending will be conducted b

英文关键词： fracture property；small-sized specimen；compliance method；constraint effect；theoretical fatigue crack growth model