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作为斜拉桥结构主要承重构件的主梁,其可靠性关系到整个结构体系的安全.有限元可靠度方法对于大型复杂结构的可靠度分析有明显的优势,基于此方法研究珠江黄埔大桥斜拉桥的主梁可靠度并对其进行了敏感性分析.考虑几何非线性的影响,建立了基于有限元方法的斜拉桥主梁可靠度计算模型,通过对有限元列式直接微分的方法获得结构响应的梯度,采用一次可靠度方法计算可靠度指标,并根据计算结果直接对随机变量分布参数进行了敏感性分析.计算结果表明,该桥的主梁是足够安全的;布载方式对主梁可靠度有明显影响;主梁可靠度指标β对主梁的抗弯承载能力的均值和标准差最敏感.
As the main beam of the main load-bearing component of cable-stayed bridge, its reliability is related to the safety of the whole structural system. The finite element reliability method has obvious advantages for the reliability analysis of large and complex structures. Based on this method, The main girder reliability of the bridge is analyzed and the sensitivity of the girder is analyzed.According to the influence of geometrical nonlinearity, the reliability calculation model of the main girder of the cable-stayed bridge based on the finite element method is established. By means of the direct differential finite element method, According to the calculation results, the sensitivity analysis of the random variable distribution parameters is carried out directly. The calculation results show that the main girder of the bridge is safe enough. The reliability of the beam has a significant effect; the reliability index β of the main beam is most sensitive to the mean and standard deviation of the bending load capacity of the main beam.