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The first part of this paper presented the required statistics and stochastic models for reliability analysis of the fatigue fracture of welded plate joints. This present Part 2 suggests a probabilistic damage tolerance supplement to the design S–N curves for welded joints. The goal is to provide the practising engineer with simple tools that predict the reliability against fatigue fracture during service life. The impact of the chosen fatigue design factors (FDF) and the uncertainty in the applied stresses is revealed. The effect of an in-service inspection programme is also predicted. The results are presented as dimensionless matrices and suggested for use in support of decision-making at the design stage, without any advanced fracture mechanics modelling and stochastic simulation. One important advantage of this format is that the probability levels are presented regardless of actual weld class and target service life (TSL). This is obtained by introducing the FDF as a key parameter to the results. This parameter is defined as the ratio of predicted fatigue life over TSL. FDF is always calculated in the S–N approach which is mandatory in fatigue life prediction. Various welded details (classes) will have the same reliability level for the same FDF. This is true at the end of TSL and at earlier stages, i.e. fractions of TSL. The absolute value of TSL is immaterial for a given FDF. In the case of in-service inspection, the inspection interval is also given without dimensions as a fraction of TSL.
Only the influence of future scheduled inspections is treated. Updating based on actual inspection results is not included as the scope of work is inspection planning at the design stage. Results for some frequent cases occurring in practice are readily derived and presented. 相似文献
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城市轨道交通无缝线路应力放散施工面临有效作业时间不充裕、对供电及信号等轨旁设备影响大、可能影响次日运营等困难。以北京地区某实际工程为例,采用细致筹备、"可视化"现场分工、全方位的专业保障等措施,安全高效地完成全线的无缝线路应力放散。并详细介绍了城市轨道交通运营期的无缝线路应力放散和调整施工组织及供电、信号系统保障措施。 相似文献
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计算比较了钢筋混凝土、方钢管混凝土和带肋方钢管混凝土柱的工程造价,结果表明:带肋方钢管混凝土柱比方钢管混凝土柱节省了约42%左右的钢材费用,降低了35%的工程造价;虽然带肋方钢管混凝土柱的工程造价比钢筋混凝土柱高出了47%,但带肋方钢管混凝土柱的施工方便,且可以缩短一半以上的施工工期;在桥墩中采用带肋方钢管混凝土,不仅使墩身具有较大的强度和刚度,而且使桥墩结构轻巧美观,因而综合经济效果良好。 相似文献
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针对高速动车组焊接构架角焊缝处应力集中无法采用名义应力法识别的问题,基于结构应力法,将角焊缝焊趾处的非线性应力分解为满足外载荷平衡的结构应力和自平衡的缺口应力,然后根据力的平衡方程得到各节点力及其力矩与线力及其线力矩间的对应关系,进而推导出结构应力的计算公式,并给出角焊缝应力集中识别流程;基于所给出的算法和识别流程,采用C/C++以及ANSYS软件提供的APDL语言开发出焊接结构应力识别专用软件WSS,对某高速动车组焊接构架上诸多角焊缝应力集中进行识别,验证了基于结构应力的角焊缝应力集中识别方法不仅能给出应力集中的具体位置,还能给出具体的应力峰值及其对应的疲劳寿命,可用于优化高速动车组焊接构架的抗疲劳设计。 相似文献
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Introduction Welded turnout is a key part for continuouswelded rails (CWRs). Longitudinal force and dis-placement of rails should be considered in the designof welded turnout. When the distance between thewelded turnouts at places like railway stations is… 相似文献
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通过对钢轨焊前激光自动测量方案的分析、论证,提出计算机仿真拟合虚拟钢轨外型,由计算机与标准钢轨参数比对,计算出钢轨外型数据的测量方法。在此基础上,利用多组钢轨外型轮廓进行自动优选配轨的模式,提高配轨精度和效率。 相似文献