基于支持向量回归的桥梁抗震动力可靠度计算

发布时间：2018-05-21 15:18

本文选题：桥梁工程 + 可靠度　；参考：《公路交通科技》2017年09期

【摘要】：为了满足桥梁结构基于性能的抗震设计需求,提高桥梁抗震动力可靠度分析计算效率,提出一种基于支持向量回归(SVR)的桥梁抗震动力可靠度分析计算方法。该方法综合考虑了结构参数随机性和地震动激励随机性的影响。在ANSYS有限元分析软件中建立桥梁有限元数值分析模型,进行随机振动分析计算以确定结构在随机地震动激励作用下的响应功率谱;进而通过首次超越破坏准则得到桥梁结构在地震作用下的失效概率。采用均匀设计试验方法(UD)在结构参数样本空间选取合适的试验点,利用支持向量回归建立起结构参数与失效概率的对应关系式,再通过连续型随机变量的全概率公式得到结构在双重随机性下的失效概率。最后以一座主跨180 m的高墩大跨连续刚构桥为工程背景进行抗震可靠度分析计算,结果表明:采用UD-SVR方法拟合关于结构参数与失效概率的响应面函数进行可靠度分析计算,对复合随机系统的动力可靠度计算具有较高的效率,为复杂结构的抗震动力可靠度分析计算提供了一种新的思路。
[Abstract]:In order to meet the requirements of performance-based seismic design and improve the efficiency of seismic dynamic reliability analysis and calculation of bridges, a bridge seismic dynamic reliability analysis and calculation method based on support vector regression (SVR) is proposed. The effect of structural parameters randomness and ground motion excitation randomness is considered in this method. The finite element numerical analysis model of bridge is established in ANSYS finite element analysis software, and the random vibration analysis is carried out to determine the response power spectrum of the structure under random ground motion excitation. Furthermore, the failure probability of bridge structure under earthquake action is obtained by the first time transcending the failure criterion. The uniform design test method (UD) is used to select the appropriate test points in the structural parameter sample space, and the corresponding relationship between the structural parameters and the failure probability is established by using support vector regression. Then the failure probability of the structure under the double randomness is obtained by the full probability formula of the continuous random variable. Finally, the aseismic reliability analysis and calculation of a long-span continuous rigid frame bridge with high piers and large spans with main span of 180m is carried out. The results show that the reliability analysis and calculation are carried out by using UD-SVR method to fit the response surface function of structural parameters and failure probability. The calculation of dynamic reliability of complex stochastic system has a high efficiency and provides a new idea for the seismic dynamic reliability analysis of complex structures.
【作者单位】：长沙理工大学土木与建筑学院;
【基金】：国家重点基础研究发展计划(九七三计划)项目(2015CB057701) 国家自然科学基金项目(51378081,51308073) 桥梁结构安全控制湖南省工程实验室基金项目(14KD16)
【分类号】：U442.55

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