摘要
提出了一种在ANSYS中直接分析大跨桥梁三维全模态颤振的有限元模型和频域方法。该有限元模型采用ANSYS的自定义单元Matrix27来模拟桥面受到的自激气动力,而将单元Ma-trix27的刚度或阻尼矩阵描述成风速和振动频率的函数。通过阻尼特征值分析,确定风-桥耦合系统的各复特征值,其中复特征值的实部为阻尼而其虚部则为振动频率;并给出了求解系统各阶复模态特性随风速变化的迭代算法。最后以一简支梁桥和一悬索桥算例验证了颤振分析模型和方法的正确性和可靠性。该方法能使桥梁设计人员和研究人员可以直接利用ANSYS来分析大跨桥梁的耦合颤振。
Authors presented a finite element (FE) model and frequency analysis method for analyzing 3-D full-mode flutter of long-span bridges using ANSYS software. This model utilized a special kind of element Matrix27 in ANSYS to simulate the aeroelastic forces acting on bridges, wherein the stiffness or damping matrixes of Matrix27 elements were described as function of wind velocity and flutter derivatives. Using this FE model, damped complex eigenvalue analysis was then carried out to determine the complex eigenvalues of wind-bridge coupled system; the real part of complex eigenvalues was damp while the imaginary part was vibration frequency. The iteration algorithm for solving variation of system order was put forward. Validity of the method was verified and a suspension bridge. The proposed method enabl practitioners to analyze flutter instability by using ANS complex mode property vs wind velocity by example of a simple-supported bridge es the bridge designers and engineering YS.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2007年第5期41-47,共7页
China Journal of Highway and Transport
基金
国家自然科学基金项目(50478051)
国家自然科学基金重大项目(59895410)
关键词
桥梁工程
全模态颤振
有限元方法
频域分析
bridge engineering
full-mode flutter
FEM
frequency domain analysis