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工程材料与结构的失效及失效分析 总被引:3,自引:1,他引:3
本文简要介绍了工程材料与结构的失效和失效分析的基本概念,阐述了失效分析在现代社会经济生活中的重要地位和作用,综述了失效分析的主要技术及其分析思路.指出了产品失效监测与预防、新型材料的失效机制以及建立和完善失效分析资源共享系统应作为工程材料与结构失效分析的重要发展方向. 相似文献
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根据对现有的压力容器、石油管道腐蚀失效案例和现有失效知识的分析与总结,提出了晶间腐蚀和氢致开裂两种模式的腐蚀失效特征。依据这些失效特征建立相应的两种腐蚀失效模式的失效判断规则,根据这些失效规则运用COM Wizard、数据库技术和可靠性技术建立有效的腐蚀失效模式诊断专家系统。该专家系统根据输入的腐蚀失效特征来识别案例的腐蚀失效模式并给出综合可信度作为诊断结果的评价参数。 相似文献
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疲劳损伤定量分析与失效评估研究进展 总被引:4,自引:2,他引:2
本文对疲劳损伤定量分析的理论和模型、断口定量分析疲劳寿命、疲劳应力以及对工程构件安全使用具有重要意义的基于损伤容限设计思想的原始疲劳质量与失效评估技术的研究现状进行了分析.通过断口定量反推疲劳应力和疲劳寿命应用最多的是Paris公式,疲劳裂纹萌生寿命目前还无法直接从断口上反推出来,一般通过人为设定a0值的方法计算疲劳裂纹萌生寿命.相对而言,国外对在役构件的剩余寿命评估方面开展了较多的工作.本文分析比较了国内外在疲劳损伤定量分析与失效评估研究的侧重点和思路的异同,并指出了加强失效分析在产品设计、生产、使用和维护各个环节的应用力度及开展失效评估技术研究是失效分析领域发展的两个重要方向. 相似文献
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The vulnerability of hearing aid devices to corrosion is critical due to their exposure to various kinds of ionic contaminants from the human body, such as sweat, sebum, and so forth, and harsh climatic conditions such as high temperature, humidity, and atmospheric pollutants. The device failure rate will vary depending upon the type of geographical location at which the device is used and root cause failure analysis is a crucial tool to understand the effect of geographical location on corrosion failures. In this study, field failed hearing aid devices from Europe, the United States, and Japan markets were investigated using a scanning electron microscope and elemental dispersive spectroscopy to locate failure mechanisms and causes. Information from the analysis was used for statistical analysis to compare the performance of the devices in the three markets based on failure percentage and failure probability for different parts and components. Solder terminals, battery contacts, light-emitting diodes, and wireless-link coil showed consistent and high failure probability across all three markets, whereas a higher failure rate for microphones was found in Europe and the United States market as compared to the Japanese market. The majority of the components corrosion failures occurred in the presence of high chloride ions from human sweat and the atmospheric conditions, whereas potassium hydroxide from the leakage of Zn–air battery was found as the additional cause for microphone failure. 相似文献
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主轴是综合传动装置中的核心元件,其可靠性直接影响综合传动装置的正常运行。针对综合传动装置主轴的疲劳失效模式,在有限元仿真的基础上考虑参数不确定性进行可靠性分析。针对疲劳断裂的主轴建立模型进行瞬态动力学仿真,获取承载工况下最大剪切应力。在此基础上考虑参数分散性对主轴强度与所受应力的影响,进行不确定性分析,并基于广义应力-强度干涉理论,运用蒙特卡洛抽样方法进行可靠度计算。在实际使用中,特殊任务下多次发生未预料的断轴故障,主轴的实际使用寿命远低于设计寿命,以该特殊任务为例进行主轴的可靠性分析。研究结果表明:针对疲劳断轴故障,采用考虑不确定性的可靠性分析方法可行。通过案例分析得到了主轴特殊工况下的疲劳寿命。 相似文献
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Xi-ling LIU Ke-bing LUO Xi-bing LI Qi-yue LI Wei-hua WANG Feng-qiang GONG 《中国有色金属学会会刊》2017,27(3):648-655
A laser technique based scanning system was employed to make a comprehensive scanning through borehole for unmapped cavity under open pit bench, then the three-dimensional data will be obtained, and these data were used for theoretical analysis and numerical simulation to analyze the stability of cap rock. Acoustic emission techniques were also adopted to carry out long term real time rupture monitoring in cap rock. Therefore, a complete safety evaluation system for the cap rock was established to ensure safe operation of subsequent blasting processes. The ideal way of eliminating collapse hazard of such cavity is cap rock caving through deep-hole blasting, thus, two deep-hole blasting schemes named as vertical deep-hole blasting scheme and one-time raise driving integrated with deep-hole bench blasting scheme were proposed. The vertical deep-hole blasting scheme has more explosive consumption, but the relatively simple blasting net work structure can greatly reduce workloads. However, the one-time raise driving integrated with deep-hole bench blasting scheme can obviously reduce explosive consumption, but the higher technical requirements on drilling, explosive charging and blasting network will increase workloads. 相似文献
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基于风电场现场数据,根据故障率、故障时间和维修成本等指标确定影响风力机可靠性的主要零部件。利用FTA法分析主要零部件故障的具体原因;采用相关性分析法分析风力机故障率与环境因素(风速、温度及环境湿度)之间的相关性;利用季节指数分析风力机故障率的季节性特征。结果表明:液压系统﹑电气控制系统和偏航系统故障是造成风力机故障率高的主要原因,故障率占比达67.91%;发电机和传动系统虽然故障率较低,但其平均故障时间和维修成本更高;故障率与风速、温度和湿度存在明显相关性,其中故障率与风速存在负相关关系,与温度和环境湿度存在正相关性。 相似文献