The Crack Detection Using Dynamic X-ray Stress Measurement during Fatigue Test

疲劳试验中动态X射线应力测量的裂纹检测

基本信息

批准号：
11650103
负责人：
OHYA Shin-ichi
金额：
$ 1.6万
依托单位：
Musashi Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650103/
关键词：
X-ray stress measurement Single exposure technique Detection of fatigue crack Actual stress distribution Surface crack Internal crack Residual stress distribution 疲労強度片持ち回転曲げ疲労試験ショットピーニング処理圧縮残留応力

项目摘要

The purpose of this investigation is to detect both a surface and an internal fatigue cracks from actual stress distribution in the surface of specimen by using X-ray diffraction technique during fatigue test.In 1999, an apparatus to measure actual stress distribution along circumference of specimen was fabricated by use of a cantilever type rotary bending fatigue machine and a stress analyzer based on single exposure technique with two position sensitive proportional counters. The method to collect separately the diffraction profile at each position along circumference of specimen was developed. Actual stress distributions at the maximum tensile applied stress were measured using an annealed carbon steel S45C specimen during fatigue test.As a result in 1999, the shape of actual stress distribution was keeping stable with increasing number of stress cycles until surface crack initiation. After surface crack initiation, the actual stress at the position of surface crack initiation was d … More ecreased suddenly near 0 MPa, and the distribution was shaped "V" type. The "V" type distribution was appeared when crack length reached greater in size than a width of irradiation area.In 2000, the actual stress distributions on shot-peened S45C specimen were measured during fatigue tests to clarify the behavior of compressive surface residual stress through fatigue process. As a result in 2000, the actual stress at every position on specimen circumference was roughly the same value as the algebraic sum of the compressive residual stress and the maximum tensile applied stress until surface crack initiation. However, after a macro surface crack was appeared, the actual stress distribution was showed V-shape at crack position. The actual stress at the bottom of V-shaped distribution was the same value as the compressive residual stress.In 2001, the actual stress distributions on shot-peened ductile cast iron FCD600 specimens were measured during fatigue tests to clarify a possibility of the internal fatigue crack detection using change in surface actual stresses distribution. As a result in 2001, it was confirmed that the peak position in the actual stress distribution agreed with the internal crack position.The method proposed in this investigation is useful for detecting a position of both a surface and an internal cracks. On the other hand, the residual stress distributions showed no significant change even where the internal crack and the surface cracks existed, whereby the crack could not be detected by change in the residual stress distribution. Less

这项投资的目的是通过在疲劳测试期间使用X射线衍射技术来检测样品表面的实际压力分布的表面和内部疲劳裂纹。在1999年，一种基于悬臂类型的旋转弯曲机和基于单个曝光技术的压力分析来制造一种用于测量样品循环的实际应力分布的设备，从而制造出样品的实际应力分布。开发了沿着试样圆的每个位置分别收集衍射轮廓的方法。在疲劳测试期间，使用退火碳钢S45C样品测量了最大拉伸施加应力的实际应力分布。由于结果，实际应力分布的形状一直保持稳定，并随着压力循环的增加而保持稳定，直到表面裂纹启动。在表面裂纹开始后，表面裂纹启动位置的实际应力是D…突然在0 MPa附近突然诱发，并且分布形状“ V”类型。当裂纹长度达到尺寸大于辐射区域的宽度时，出现“ V”类型分布。在2000年，在疲劳测试期间测量了射击的S45C样品上的实际应力分布，以阐明通过疲劳过程来阐明压缩表面残留应力的行为。结果，在2000年，样品循环的每个位置的实际应力大致相同的值与压缩残留应力的代数和最大拉伸应力，直到表面裂纹启动为止。但是，在出现宏观表面裂纹后，在裂纹位置显示了实际应力分布。 V形分布底部的实际应力与压缩残留应力相同。在2001年，在疲劳测试期间测量了射击的延性粘液铸铁FCD600标本上的实际应力分布，以阐明使用表面实际应力分布的变化使用内部疲劳裂纹检测的可能性。结果，2001年证实，实际应力分布中的峰位置与内部裂纹位置一致。本投资中提出的方法可用于检测表面和内部裂纹的位置。另一方面，即使存在内部裂缝和表面裂纹，残留应力分布也没有显着变化，从而无法通过残留应力分布的变化来检测裂纹。较少的