论文部分内容阅读
1. 引言持久强度系与时间有关表征材料高温性能的力学量,定义为一定温度下材料至规定时间破断的应力值。通常,时间大多定为十万或十万小时以上。就工业试验而言,不论时间或经费上的考虑,都不能苛求试验室进行这么长的试验,原始数据的外推处理往往不可避免,而最长试验时间和试样总数也应给出合理限度。这样,持久强度的精度,不仅存在材质分散性和试验误差的影响,还必须顾及数据处理过程的可靠性。2. 考核途径持久强度试验获得的一组原始数据,是由试验温度T_i、试样应力σ_i和破断时间τ_i三要素组成。它们间建立的各种关系式,经适当变量变换均可转化为多元线性方程组。其数学模型为y_i=b_0+b_lx_(Ji)+b_2x_(2i)+…+b_px_(pi)+ε_i ε_i是N个相互独立且服从同一正态分布N(0,S)的随机变量。因此,只要估计出b_0、
1. Introduction Persistent strength is a mechanical quantity that characterizes the high temperature properties of a material and is defined as the stress value at which a material breaks at a given time and at a given time. Usually, the time is mostly set at 100,000 or more than 100,000 hours. As far as industrial tests are concerned, regardless of time or financial considerations, it is not possible to demand such long tests in the laboratory. Extrapolation of raw data is often unavoidable, and the longest test time and the total number of specimens should also give reasonable limits. . In this way, the accuracy of the long-term strength not only has the effect of material dispersion and test error, but also must take into account the reliability of the data processing process. 2. A set of raw data obtained by the test method for the persistence strength test consists of three elements: test temperature T_i, sample stress σ_i and breaking time τ_i. The various relationships established between them can be transformed into multiple linear equations by appropriate variables. Its mathematical model is y_i=b_0+b_lx_(Ji)+b_2x_(2i)+...+b_px_(pi)+ε_iε_i are N random variables that are independent and obey the same normal distribution N(0,S). So, as long as b_0,