Dynamic Optimization Of Crane Reducer Based On Vibration Response Simulation And Radiated Noise Prediction

With the development of marine trade, there is demanding requirement of craneused in ports all over the word, including large carrying capacity, high reliability, smallvibration, low noise, lightweight and stability character. The overall behavior of a craneis mainly determined by its reducer in it. But the current problems exist on cranereducer are the low efficiency and bad dynamic characters, and this inevitably inhibit itsutility and economy. Therefore, the research on dynamic response simulation, vibrationnoise evaluation and dynamic optimization of crane reducer is of great theoretical andpractical significance.This paper is supported by National Science and Technology Support Program. Inorder to achieve the best dynamic performance of cranes, the dynamic responsesimulation, vibration noise evaluation, structural-acoustic sensitivity and multi-objectiveoptimization are carried out. The main research work in this paper can be summarizedas follows:â‘ In the ANSYS software, The finite element model of coupling system whichconsist of gear-rotor-bearing-housing is established considering the internal excitationincluding stiffness excitation, error exaction, meshing impact exaction and externalexcitation resulted from the variation of motor torque. Employing the method of blockLanczos, the natural frequency and normal mode of crane reducer are obtained. Thetransient response of the reducer is studied using modal superposition method.Subsequently, the vibration displacement, velocity and acceleration of crane reducer areobtained.â‘¡The frequency domain response of the nodes on the surface of housing areobtained after the Fourier transformation of the time domain response. Taking thefrequency domain response as boundary condition, the acoustic boundary elementmodel of the housing is established in SYSNOISE software. Using direct boundaryelement method, the acoustic pressure contour on the housing surface and the radiationnoise at specific field points are obtained.â‘¢Picking structure wall thickness and the elastic modulus of reducer housing asdesign parameters and acoustic pressure of specific field points as acoustic parameters,the structural-acoustic sensitivity model of the reducer is established by solving themode shape sensitivity and acoustic transfer vector (ATV) respectively. Then the value of sensitivity of all field points can be obtained by coupling the structural sensitivity andacoustic sensitivity, and the analysis of structural sensitivity will provide reference forchoosing the design variable of dynamic optimization of crane reducer.â‘£With the purpose of reducing the vibration and preventing sympatheticresonance, a multi-objective optimizer is developed by employing a parametrical designlanguage and the design parameters are chosen based on structural sensitivity analysis.Employing Zero-order and First-order optimization method, the optimal combination ofdesign parameters are obtained after several iterations. Finally, the static strength anddynamic characteristics of crane reducer are re-evaluated using the best designparameters.