桥梁结构钢机械性能指标的概率分布  

Probability Distribution of Mechanical Performance Index of Bridge Structural Steel

作　　者：杨帆[1] 刘岑[2] 刘兵[1] 吴元祥[1] 张红卫[1] 刘小宁[1] YANG Fan;LIU Cen;LIU Bing;WU Yuanxiang;ZHANG Hongwei;LIU Xiaoning(School of Mechanical Engineering,Wuhan Polytechnic College of Software and Engineering Wuhan 430205)

机构地区：[1]武汉软件工程职业学院机械工程学院,武汉430205 [2]湖北轻工职业技术学院机电工程学院,武汉430070

出　　处：《工业安全与环保》2018年第9期64-67,75,共5页Industrial Safety and Environmental Protection

基　　金：湖北省教育厅科研项目(B2016545);武汉黄鹤英才(教育)计划资助项目

摘　　要：屈强比、下屈服强度与抗拉强度是桥梁结构钢机械性能的重要指标,其概率分布是桥梁结构强度可靠性设计的基础。应用概率论与数理统计知识,建立了屈强比、下屈服强度与抗拉强度分布规律与分布参数的分析方法。基于室温有效拉伸试验数据,在双侧置信度为99%时,研究了桥梁结构钢Q420NHY中厚板屈强比与下屈服强度的概率分布。显著度为0.05时,屈强比与下屈服强度是基本符合正态分布的随机变量。屈强比的均值不小于0.627 0且不大于0.669 4,标准差不小于0.022 37且不大于0.054 48。屈服强度均值不小于339 MPa且不大于353 MPa,标准差不小于7.87 MPa且不大于19.2 MPa。如果Q420NHY钢室温抗拉强度基本符合正态分布,其均值应不小于507 MPa且不大于563 MPa,标准差不小于11.3 MPa且不大于31.0 MPa。Yield ratio,lower yield strength and tensile strength are important indexes of mechanical properties of structural steel for bridge and the probability distribution is the basis of bridge structure strength reliability design.By applying probability theory and mathematical statistics knowledge,it is established the analysis method for distribution law and distribution parameter of yield ratio and lower yield strength.Based on the steel Q420NHY effective tensile test data at room temperature and when bilateral confidence is 99%,the probability distributions of yield ratio,lower yield strength and tensile strength are studied.Significant at 0.05,the yield ratio and lower yield strength are variables with normal random basically.The yield ratio mean is not less than 0.672 0 and not greater than 0.669 4,and the standard deviation is not less than 0.022 37 and not greater than 0.054 48.The lower yield strength mean is not less than 339 MPa and not greater than 353 MPa,and the standard deviation is not less than 7.87 MPa and not greater than 19.2 MPa.If tensile strength is a random variable with normal distribution,the tensile strength mean should be not less than 507 MPa and not greater than 563 MPa,and the standard deviation should be not less than 11.3 MPa and not greater than 31.0 MPa.

关 键 词：桥梁结构钢 屈强比 下屈服强度 概率分布 

分 类 号：U444[建筑科学—桥梁与隧道工程]