区间参数结构可靠性分析新模型

New model for reliability analysis of structures with interval parameters

针对未确知性信息的区间均布假定盲目保守的缺陷,结合工程参变量的典型特征,运用Chebyshev不等式和"3σ原则",并在遵循工程安全原则的前提下,基于若干保守假定提出并建立了未确知性信息的分段描述模型,给出了分段描述随机数生成策略和非概率可靠度计算的Monte Carlo仿真方法。通过算例进行了模型验证,并与区间均布假定和概率分布假定作了比较。结果表明:分段描述方法相对于区间均布假定能更好地反映工程实际而不引起附加风险,计算结果精确、有效。

In view of defects in the assumption of uniform distribution of uncertain information,an advanced description approach named fragment description model was proposed by using Chebyshev in-equality and ＂3σ＂ principle.The interval bounds were considered as the edge of 3σ of stochastic variable.Based on the Chebyshev inequality,a series of conservative assumptions were made which were equal to assumptions of higher dispersion degree.The conservative probability density function named fragment description was given.The technique of sample data generation was proposed.The Monte Carlo simulation method for non-probabilistic reliability was given.The two examples given prove the feasibility and reasonableness of fragment description model.Comparison with other models shows that the fragment description approach can better reflect the reality of engineering and that the analytical results are more accurate and valid.