建筑结构安全评估模型修正方法研究

Model updating of building structures for safety assessment

很多建筑结构通过安装加固装置来提高安全性能,因此有必要研究这类工程结构的安全评估问题。利用结构安装加固支撑前后的模态信息,建立一种针对安全评估模型的修正新方法。在此基础上,通过考虑结构刚度矩阵元素与层刚度系数的关系,建立结构层刚度系数的识别方法。用该方法能迅速减小识别方程的规模和改进识别方程病态特性。结果表明:采用新模型修正方法可以识别结构的刚度矩阵系数和层刚度系数,无噪声时识别精度可达100%,有噪声时识别精度不低于90%。

Many civil engineering structures are reinforced by using strengthening devices so as to enhance their safety. Therefore,it is essential to investigate the safety assessment of this kind of civil engineering structures. A novel model updating approach was worked out for structural safety evaluation by using the modal information of structures without /with additional stiffness braces. Furthermore,an identification method was worked out for floor stiffness coefficients by considering the relationship between floor stiffness coefficients and coefficients in the stiffness matrix. This approach can substantially reduce the number of unknown parameters of identification equation and at same time improve the ill-conditioning properties of identification process. The observations made in this study indicate that new model updating approach proposed the floor stiffness coefficients and coefficients in the stiffness matrix can be identified accurately by using the approach worked out by the authors,and that detection accuracy is 100% for noise free case and counterpart with noise contamination is no less than 90%.