弹性支承索参数识别方法

为了准确识别索参数,提出了采用有限单元法和系统参数识别技术相结合进行索参数识别的方法。考虑索的垂度、抗弯刚度、弹性嵌固和弹性支承等因素建立有限单元模型,采用反映出索非线性振动特性的轴力的梁单元模拟索。利用索特征值关于模型参数的灵敏度矩阵,建立了参数识别的理论/试验频率差与模型参数之间的关系式。该方法基于实测频率,通过迭代可以同时识别拉索索力和抗弯刚度。数值算例和试验验证了该方法的准确性和实用性。

Parameter Identification for Flexibility Support Cable

Cable parameter identification in a cable structure is very critical in both construction and maintenance of the structure.A new parameter identification method is presented,and it can accurately identify the cable parameters,such as cable tension and flexural stiffness based on finite element model(FEM) and system identification technology.Considering the effects of sagging,flexural stiffness,tension,boundary conditions,and flexibility support,three-node-beam-element FEM is formed to study nonlinear vibration of cables.An eigenvalue sensitivity matrix is obtained from the first-order Taylor series expansion of the non-dimensional eigenvalues with respect to the parameters to be identified.The equations relating the parameters identified to the differences between the analytical and the measured frequencies are established.The parameters can be determined accurately through the proposed equations in a new iterative fashion.The precision of the identified parameters and the convergence are enhanced.The numerical and experimental study is conducted to verify the identification method.