水工弧形空腔闸门动力特性数值分析

大尺寸弧形钢闸门振动剧烈时可能会引起动力失稳破坏。为了解新型翻转式弧形空腔闸门的动力特性，通过Fortran语言自编用户子程序，利用商业有限元软件ABAQUS二次开发功能将模型试验测定离散的水流脉动压力数据转化为作用在闸门上的水动力荷载，基于随机振动分析方法对该空腔闸门进行结构动力数值仿真:①对不同工况下的闸门自振特性进行计算，得到闸门的自振频率和振型；②根据频谱分析理论，对水流脉动压力时域曲线进行了频谱分析；③计算了不同工况下闸门的随机振动响应；④编写了位移、应力最值处理程序。计算结果表明:闸门结构局部应力较大，超出结构容许应力，需对闸门结构进行修改优化，否则结构局部强度不满足要求。

Numerical analysis of dynamic characteristics of hydraulic radial cavity gate

Severe vibration of large-scale radial steel gates can induce dynamic instability damage. In order to investigate dynamic characteristics of a new type of radial gates, the reversed radial cavity gate, a new FORTRAN subroutine was developed in this study. Using the two development functions of the finite element software ABAQUS, the data of the dispersion flow pressure fluctuation measured by the model tests are transformed into hydrodynamic loads upon the gate. Based on the random vibration analysis method, the dynamic numerical simulation of the cavity gate is carried out. The complete analysis method consists of the following steps: ① estimate the frequency and vibration mode for the gate under different working conditions; ② analyze the spectrum for the time series of fluctuating pressure of the water flow; ③quantify the response of the gate to the random vibration under different working conditions; ④develop the subroutine to analyze the extreme values of displacement and stress for the gate. The analysis results show that the local stress of the gate is larger than the allowable stress of the structure. This requires modifications and optimizations of the gate structure, otherwise the local strength of the structure cannot meet the stability requirements. This numerical analysis method has a potential to be used for improving the dynamic stability of the hydraulic radial gates.