【摘要】 本文所介绍的计算结构可靠指标的几何法既适用于随机变量为正态分布、对数正态分布及极值Ⅰ型等分布情况,也适用于基本随机变量相关的情况.该法将各种分布的随机变量转化成标准正态变量,然后用迭代法求解.几何法与过去常用求可靠指标的一次二阶矩法相比,具有迭代次数少、收敛快、精度高的优点,并在计算出可靠指标的同时,求出设计验算点值.当进一步研究随机有限元和结构系统的可靠度时,需对结构反复进行分析,有时需多次求可靠指标,这时,用几何法求解将更合适.更多还原

【Abstract】 Reliability of a structure is often illustrated by a reliability index in engineering.Geometric for solving reliability index of structures is suita-ble for the cases that random variables are normal distribution,lognor-real distribution,or extremal type I distribution etc..The method can also be used to solve the problems having correlated condition among the variables.The procedure of the method is as follows,first all variables are transformed into standard normal variables,then iteration method is used to solve the problem.The method has the advantage of tess iterative times,faster convergence speed and higher accuracy in making comparison with that of FOSM method.It also has advantages of that the design points can be easily obtained,while reliability index obtained.The method is widely adopted in the random finite element method,especially in solving the problem of reliability of structural system.更多还原