大跨度悬索桥颤振可靠度分析的改进响应面法  

A modified response surface method for flutter reliability analysis of long-span suspension bridges

作　　者：程进[1] 肖汝诚[1] 

机构地区：[1]同济大学,上海200092

出　　处：《土木工程学报》2006年第7期69-73,共5页China Civil Engineering Journal

基　　金：国家自然科学基金(50408037)

摘　　要：介绍一种新的计算悬索桥颤振可靠度方法——改进响应面法。该方法利用传统响应面法将极限状态方程近似表达为简单的多项式形式,有效地解决FORM和SORM无法求解隐式极限状态方程的可靠度问题。另外,改进响应面法的使用还能有效地利用现有的确定性颤振分析软件。通过引入有限元方法,改进响应面法可应用于悬索桥颤振可靠度问题。通过使用重要抽样技术,提高改进响应面法的计算效率和计算精度,有效地解决传统响应面法在结构可靠度较大或失效概率较低时出现的迭代不收敛问题。数值算例验证该方法的效率和精度。最后,用该方法计算江阴长江大桥的颤振可靠度,结果表明基于经验公式的改进响应面法会过高地估计大跨度悬索桥的颤振可靠度。实际的悬索桥颤振可靠度应该采用基于有限元法的改进响应面法进行计算。A modified response surface method is presented for calculating the flutter reliability of suspension bridges through a combination of the advantages of conventional response surface method （RSM） , finite element method （FEM） , first order reliability method （FORM） and sampling updating method. Combing the RSM method with FORM, the modified response surface method can calculate the reliability of complex structures, of which the limit state functions are not explicitly known. Also, it is feasible to use the existing deterministic flutter finite element code without modifications. Using FEM, the modified response surface method is extended to perform flutter reliability analysis of suspension bridges. The efficiency and accuracy of the modified response surface method are improved with the aid of a sampling updating technique. The efficiency and accuracy of the modified response surface method are verified with numerical examples. The flutter reliability of the Jiangyin Bridge is analyzed by using the modified response surface method. The results indicate that the method based on an empirical formula, in which the limit state function is explicitly represented, overestimates the flutter reliability of suspension bridges. The flutter reliability could be more accurately analyzed by using the proposed method based on a deterministic finite element method in which the limit state function is implicitly represented.

关 键 词：悬索桥 可靠度 失效概率 响应面法 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]