Development of Ultrascnic Flaw Detection System for Quantitative Evaluation of Fatigue Damage of Existing Steel Structures

现有钢结构疲劳损伤定量评价超声波探伤系统的研制

基本信息

批准号：
15206055
负责人：
MIKI Chitoshi
金额：
$ 28.79万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

This study considered following items and show the possibility of developing UT system for quantitative evaluation.1. Development of a database for the fatigue crack detection in existing steel structures and consultation system based on the database :The database of the location, cause, and retrofit work of the fatigue damage was developed and it was showed that the importance of the detection of cracks from defect for the maintenance.2. Numerical simulation about characteristic of ultrasonic echo :In order to develop linear array flaw detection system, wave propagation simulation was carried out to optimize the arrangement of piezoelectoric device in proves. Then effective arrangement for 2 MHz and 5 MHz were proposed.3. Verification of the characteristics of ultrasonic echo from fatigue crack :It was showed that crack tip opening and closing behavior could be detected as the change of ultrasonic echo intensity non-destructively, and that possibility of fatigue crack identification by visualization using SAFT technique.4. Development of array ultrasonic flaw detection system :Three dimensional flaw detection systems in steel using tandem or two dimensional array probes were developed.5. Improvement of the accuracy of ultrasonic flaw detection systems by signal processing :Three dimensional visualization techniques with high objectivity and accuracy was developed. Accuracy of visualization to detect the location of crack tip by SAFT technique etc was evaluated.6. Verification by experiment using steel structural models :Ability of the weld defects detection was verified by using the model of steel bridge frame piers, which is fatigue problem was found recently, then it was checked that internal weld defects can be detected accurately even if the defect had three dimensional shapes.From the these results, it can be established that ultrasonic flaw detection system to evaluate fatigue damage objectively.

这项研究考虑了以下项目，并显示了开发用于定量评估的UT系统的可能性1。开发了基于数据库的现有钢结构和咨询系统中疲劳裂纹检测的数据库：开发了疲劳损害的位置，原因和改造工作的数据库，并表明从维护中发现裂缝的裂缝的重要性是维护的重要性。2。关于超声波回声特征的数值模拟：为了开发线性阵列漏洞检测系统，进行了波传播模拟，以优化在证明中的压电部设备的排列。然后提出了2 MHz和5 MHz的有效排列3。通过疲劳裂纹验证超声波回声的特征：显示裂纹尖端的开口和闭合行为可以被检测到超声波回声强度的变化无损，并且使用SAFT技术可视化疲劳裂纹识别的可能性。4。阵列超声波检测系统的开发：使用串联或二维阵列探针在钢中的三维缺陷检测系统。5。通过信号处理来提高超声波检测系统的准确性：具有高客观性和精度的三维可视化技术。评估了可视化的准确性以检测通过SAFT技术等检测裂纹尖端的位置。6。 Verification by experiment using steel structural models :Ability of the weld defects detection was verified by using the model of steel bridge frame piers, which is fatigue problem was found recently, then it was checked that internal weld defects can be detected accurately even if the defect had three dimensional shapes.From the these results, it can be established that ultrasonic flaw detection system to evaluate fatigue damage objectively.