可靠指标在非线性极限状态方程下的误差判别

Determination of Error on Reliability Index Arising from Non linear Limiting State

从可靠指标β的本质意义出发，揭示了极限状态非线性引起的误差性质，证明了这种误差非统计意义的结论，提出了判别这种误差性质的一种数学方法，并给出了算例．分析表明，功能函数非线性对结构可靠度计算结果有时影响显著，当其非线性性质为凹向高斯空间的原点时，将偏于不安全．

In this paper,on the basis of the essential meaning of reliability index β ,the essence of error arising from non linear limiting state is revealed ,the conclusion on the error is proved,a mathematic method for determining the character of error is put forward and an example is given.The result of analysis shows that the non linear limiting state has a notable influence upon structural reliability calculation sometimes and,when it is concave to the centre of the Gauss Coordinate,this influence is unfavourable to structural safety.The present method is effective.