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Development of Structural Monitoring and Inspection on Baysian Reliability Analysis

贝叶斯可靠性分析结构监测与检验的发展

基本信息

批准号：
06302062
负责人：
ITAGAKI Hiroshi
金额：
$ 6.66万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06302062/
关键词：
Structural Reliability Monitoring Desing Inspection Baysian Reliability Fracture Mechanics Sampling Method

项目摘要

In the present investigation, the applicability of structural monitoring and inspection on Baysian reliability analysis are discussed. The main results are summarized as follows ;(1) Life of structures which are subject to fatigue failures involves high degree of uncertainty and risk. In order to design such systems it is necessary to take into account several stochastic elements. As the structure ages, the relationship among initial cost, inspections, maintenance and reliability level becomes important, and it has to be studied in order to achieve a good design from the costeffectiveness point of view. This paper analyzes this relationship and proposes a method to take the best decision among a set of alternatives structural regarding structural dimensions using a new class of Baysian loss functions that are based on the concepts of under and over design.(2) Two type of fatigue monitoring methods are experimentally examined for metal structures ; fatigue crack detection and fatigue life prediction.As the detection method, five kinds of crack sensors, i.e., conductive film-sensor, conductive-paint sensor, plastic optical-fiber sensor, glass optical-fiber sensor and carbon-fiber sensor are made on an experimental basis. The sensors are bonded on the surface of a welded joint model and a compact specimen by adhesives or painting, and performances of each sensor are examined through the fatigue tests.As the prediction method, a fatigue coupon indicator of adhesive-type is developed. The main body of the coupon is a center cracked thin plate with 60mm-long, 10mm-width and 0.25mm-thickness, madefrom mild steel. The middle part in length of the plate is coated by Teflon film and the whole is sandwiched in between two thin epoxy resin plates. The coupon is bonded on a smooth specimen by adhesives, and the performance is investigated by pulsating tension and fully reversed fatigue tests.(3) We try to investigate on possibility of strain measurement by optical fiber.

在本研究中，讨论了结构监测和检验在贝叶斯可靠性分析中的适用性。主要研究结果总结如下：(1)结构疲劳失效的寿命具有高度的不确定性和风险。为了设计这样的系统，有必要考虑几个随机因素。随着结构的老化，初始成本、检查、维护和可靠性水平之间的关系变得越来越重要，为了从成本效益的角度实现良好的设计，必须对其进行研究。本文分析了这一关系，并提出了一种利用基于过设计和欠设计概念的贝叶斯损失函数在一组关于结构维数的备选结构中做出最佳决策的方法。(2)对金属结构的两种疲劳监测方法进行了试验研究；疲劳裂纹检测与疲劳寿命预测。作为检测方法，实验制作了导电薄膜传感器、导电涂料传感器、塑料光纤传感器、玻璃光纤传感器和碳纤维传感器五种裂纹传感器。通过胶粘剂或喷漆将传感器粘接在焊接接头模型和压实试样表面，并通过疲劳试验检验每个传感器的性能。作为预测方法，提出了胶粘剂型疲劳副指标。套票主体为一块长60mm，宽10mm，厚0.25mm的中心裂纹薄板，由低碳钢制成。板的中间部分涂有聚四氟乙烯薄膜，整体夹在两块薄环氧树脂板之间。采用胶粘剂将复合材料粘接在光滑试样上，并通过脉动拉伸和完全反向疲劳试验研究了复合材料的性能。(3)尝试探讨光纤应变测量的可能性。