According to the stress spectrum of weaking section in fatigue test and s - n curve of classic welding joint in this section , we establish a model of life calculating by the principle of fatigue damage equivalence , then we get the relationship between the cross sustaining device ' s actual utilizing life and the load recycle number in fatigue test 根据疲劳薄弱部位在室内疲劳试验中的应力谱及该部位典型接头的s - n曲线，按照疲劳损伤等效原则建立交叉支撑装置的寿命预测模型，得到了交叉支撑装置实际运用寿命与室内疲劳试验加载循环次数的关系。
On the basis of the experimental studies of low - cycle fatigue , performed on the bhw - 35 power plant boiler drum and 12crmov pressure piping respectively , the fatigue life evaluation methods are established in this paper . all studies can be concluded as follows . p - s - n curves of bhw - 35 steel and of its weld metal are obtained with the total stain controlled low - cycle fatigue test and the probability and statistic method 本文以电厂bhw - 35钢制造的410t / h锅炉汽包和电厂12crmov压力弯管作为研究对象，在获得实验数据的基础上，建立了一套较为完整的低周疲劳寿命分析方法，主要研究内容如下：在bhw - 35钢及焊缝材料总应变控制低周疲劳试验基础上，采用概率统计分析方法对实验数据进行分析，得到母材和焊缝材料的p ? s ? n曲线。
On the basis of finite element numerical simulation technology and s - n curve data base of welded joint , the course of fatigue test of physical prototype was simulated with computer and the fatigue life of welded structure was predicted , so as to let the development of anti - fatigue design becoming possible in the designing stage of product 基于有限元数值仿真技术及焊接接头s - n曲线数据库，在计算机中模拟物理样机的疲劳试验过程，预测焊接结构的疲劳寿命，使产品在设计阶段开展抗疲劳设计成为可能。
These stud " can be concluded as following : on the basis of the bhw - 35 steel p - s - n curve and its da ' dn growth law the method of low - cycle fatigue life evaluation of 401 t / h boiler was proposed . and a mechanics model was suggested for calculating the stress of internal pressure suffering elbow . with the elbow fatigue test , a method of evaluation the fatigue growth life of pressure suffering elbow is recommended ; and the elementary use of damage mechanics on the fatigue life evaluation of the boiler drum 本文创新点为：在bhw - 35钢的p ? s ? n曲线及da / dn扩展规律的试验研究基础上，提出了410t / h锅炉汽包的低周疲劳寿命分析与预测方法；建立了一种椭圆截面变厚度弯管承受内压时的应力计算力学模型，通过压力弯管的疲劳试验，本文推荐其低周疲劳扩展寿命预测方法；将损伤力学应用到锅炉汽包疲劳寿命预测做了初步的探索。
With the typical on - axis fatigue tests to get the relative s - n curves of unidirectional laminates , executed at certain stress ratio , it is possible to predict the fatigue life of multidirectional laminates subjected to cyclic stresses of different stress ratios . this would tremendously reduce test costs for laminate structures 考虑了层压板中单向层面内多轴应力和平均应力的影响，在已知单向板在确定应力比下受典型单轴循环应力的s - n曲线的基础上，预测任意铺叠次序层压结构在不同应力比的循环载荷下的疲劳寿命。
The abilities of resisting the incubation of fatigue crack in ast101a and alti101a were tested with the high - cycle fatigue method . a method combining the maximum likelihood estimation method with the correlation coefficient method was suggested to analyze the fatigue life experimental data some of which were incomplete . the s - n curve and p - s - n curves were presented , and the influence of the loading history and the defects in specimen on fatigue life was discussed 通过高周疲劳测试方法研究了ast101a和alti101a抵抗疲劳裂纹萌生的性能，把最大似然法和相关系数法结合起来处理不完全疲劳寿命数据，给出了ast101a的s ? n曲线、 p ? s ? n曲线和疲劳极限，讨论了加载历史、缺陷等对疲劳寿命的影响。
Second , carried out the fatigue life test of the truck ' s front axles adopted grouping fatigue life test method , calculated the results on theory of probability stats , linear fitted the fatigue life data by means of the basquin equation and least squares method , acquired the mathematical model of s - n and p - s - n curve of the front axles 其次，采用成组试验法，对汽车前桥进行了疲劳寿命试验，借助概率统计方法对试验结果进行了分析计算，得到了各试验载荷下的疲劳寿命的正态分布的均值和标准差，采用basquin关系式和最小二乘法对疲劳寿命数据进行线性拟合，得到了前桥的s - n和p - s - n的关系。
To provide a practical tool for fatigue assessment , this approach is based on the so - called simplified fatigue analysis with the assumption that the long - term stress histogram of the hull structure follows the weibull probability distribution , the s - n curves used in the assessment and evabatbn are the basic design - n curves for non - nodal johts " issued by den ( department of energy of united kingdom ) , combining with computer technology the assessment procedure is programmed , which will indicate the fatigue damage condition and degree of technical status of tanker hulls 在中国船级社( ccs ) 《船体结构疲劳强度指南》和美国船级社( abs ) simplifiedfatigueanalysis的基础上，根据对油轮结构特点和货载特点的分析，讨论了油轮船体疲劳损伤的影响因素，讨论油轮疲劳强度计算方法和计算程序，引入模糊质量评级的方法，建立油轮疲劳损伤评估模型。结合先进的计算机技术，编制出油轮疲劳分析程序，采用典型实船资料，对其疲劳状态进行评估，结果与实际情况比较吻合，表明该程序具有一定的合理性，可作为油轮船公司评价油轮技术状态时在疲劳损伤方面的参考。
