空气储罐安全临界裂纹的可靠性分析

通用失效评定图在评定焊接结构安全性方面广为采用。但是,材料力学性能的测试、结构中缺陷大小的测试,客观上存在一定不确定性。因此,不论是对评定参数还是评定结果都需要进行可靠性分析。但可靠性分析需要大量数据,有时难于实现。为此,在对随机变量的实验结果进行统计分析中,采用二维单侧容限方法,从而在不增加工作量的同时,确保了分析结果的高可靠性。在空气储罐安全临界裂纹分析计算中,采用该方法处理后,应用成功-失败法对指定失效概率进行求解,裂纹尺寸变动1mm ,其安全评定的失效概率则变动几个数量级,从而在充分挖掘储罐潜能的同时,大大提高了安全临界裂纹分析的可靠度。

Reliability Analysis of Safe Critical Crack of the Air Tank

General assessment chart has been adopted widely in assessing the integrity of structural welded joint. However, objectively there are some uncertainties such as in material mechanics performances testing, and the scale of structural defects tested. So notwithstanding the parameter or the result assessed, it is necessary to undergo reliability analysis. But it is difficult to realize sometimes because it is very hard to get huge amount of data. Therefore, the way of dual dimensional unilateral allowance is adopted in statistical analysis of the experiment results of variables to ensure high reliability of the results without increasing the working load. In the calculation of the safe critical crack of the air tank after treated by this method, the specified invalidity probability would fluctuate quite a few quantity class tested by the success-fail method even when the variation of crack is only 1 mm. The potentiality of air tank would be fully used while the reliability of safe critical crack is significantly increased.