【作者】 马延辉；

【导师】 徐人平；

【作者基本信息】 昆明理工大学 ， 机械设计及理论， 2011， 硕士

【摘要】 随着科技的发展,现在的工程结构和机械装备的工作环境都发生了很大的改变,不单仅仅是在交变载荷下工作,而且需要在高温情况下工作。很多情况下,工程结构和机械装备在高温蠕变和疲劳的作用下,材料损伤产生裂纹并不断扩展,最后引起泄露或爆炸,导致重大经济损失和人员伤亡等。所以研究材料的高温蠕变可靠性对结构的安全评估具有重要的意义。本文对高温合金钢GH36钢进行高温持久强度断裂试验研究,得出三个厂家生产的GH36钢高温持久强度断裂时间数据。然后将这些分散的数据看成是随机变量,利用数理统计的方法来处理这些数据。本文探讨的主要内容如下：首先,对高温蠕变实验发展做了简要的叙述,然后对蠕变试验机的特点和工作原理作了阐述,并根据要求选择合适的实验机和试验件其次,选用了可靠性设计中常用统计分布函数的MATLAB程序,其中包含了正态分布、对数正态分布、威布尔三参数、二参数分布函数的分布特性研究、参数估计及分布拟合检验,并绘制出分布函数的线性回归图,使复杂的统计分析过程简单化。再次,利用MATLAB程序,对得到的GH36高温合金钢的高温持久强度断裂时间数据分布进行正态分布、对数正态分布、威布尔三参数、二参数分布函数的分布特性研究、参数估计及分布拟合检验,并得出各组数据的最佳分布类型。最后,是在得出每组数据最佳的分布类型上进行具有一定置信度水平的置信度区间的研究和对比分析研究,得到三个厂家生产的GH36钢高温持久强度断裂时间的置信区间；通过F检验和t检验的对比分析,认为齐钢生产的GH36钢高温蠕变数据的分散性均显著地大于43厂和二重生产的；认为二重生产的GH36钢高温蠕变和于43厂的方差无显著性差异,但二重生产的均值大于43厂的。更多还原

【Abstract】 With the development of science and technology, now the working environment of engineering structure and mechanical equipment have changed a lot,which is not only worked in alternating load, but also need to work under high temperature conditions. In many cases, when the engineering structure and mechanical equipment experiene high temperature creep and fatigue, Crack propagation is influeneed by material damage, causing leaking out or explosion.All thesestatus will lead to eeonomie losses and people casualty. So we study the material high-temperature creep reliability, it has a important significance when it is used to evaluate the safety of the structure.This paper described research that high temperature alloy steel GH36 has been tested on high temperature enduring strength and fracture experiments, and draw three factories GH36 steel high temperature enduring strength and fracture time data. And then these randomly distributed material properties of the measured datas are regard as random variables, mathematical statistical methods are used to deal with it. This paper are mainly researched on items listed below:First of all, there is a brief narration about the development of high-temperature creep experiments, and then creep test enginery characteristics and working principle are discussed, and according to the requirements of appropriate testing machine and test pieces.Secondly, the distribution characteristics, parameters estimation and hypothesis testing of the commonly used statistical distribution functions, which includes the normal distribution, lognormal distribution, the two-parameter and three-parameter Weibull are program by MATLAB, and the corresponding linear regression are charted.Thirdly, To handle the time data of GH36 steel high temperature enduring strength and fracture with the distribution characteristics, parameters estimation and hypothesis testing of the commonly used statistical distribution functions, which includes the normal distribution, lognormal distribution, the two-parameter and three-parameter Weibull are program by MATLAB, and draw the best distribution types of each data.Finally, in order to get to meet the credibility of the results of statistical analysis based on the best distribution types of each data, and draw the three factories confidence interval of high temperature enduring strength and fracture, and through the F inspection and t-test contrast analysis we can known that, the dispersion of GH36 steel high-temperature creep data of QiGang production is big than others, and there is no significant difference between erchong and 43chang about theirvariance, but erchong’s mean larger.更多还原