Structure Weight Reduction Research Of Ship Unloader Based On Orthogonal Experiment Method

As a bulk cargo handling equipment, Ship unloader plays a very important role in port bulk material handling. As the international bulk cargo ship is becoming increasingly larger, the ship unloader is becoming larger as well. Larger structure means more weight and more materials, which led to a sharp rise in cost. Therefore, the weight reduction design of ship unloader is a very important issue.Based on the 2500h/t bridge type grab ship unloader, this paper built the finite element model of the ship unloader, proposed a structure optimization method based on the orthogonal experimental method and a parametric modeling method, and developed a software based on the two methods introduced above. The research work mainly includes the following aspects:Firstly, this paper proposed a new method to ship unloader's structure optimization based on orthogonal experimental method. That is, searching for the best parameter combination through the continuous iterative orthogonal experiment. The traditional optimization method adopts a large number of finite element analysis when dealing with the optimization problem of ship unloader, while the optimization method based on the orthogonal experimental method adopts much less finite element analysis, so this method can reduce the time needed during the optimization process. This method can effectively achieve the goal of weight reduction for ship unloader and have obvious advantages of reducing the optimization time.Secondly, this paper built the finite element model of the ship unloader. Through the analysis of ship unloader's structural traits, load case and load, this paper described the way to build the finite model of ship unloader and eventually built the finite element model. By comparing the calculated data of the model with the reference data, the result proved the accuracy of the model and proved that the model can be used in the simulation calculation of ship unloader.Thirdly, this paper put forward the parametric modeling method. Parametric modeling is a very important method to improve the model building efficiency. The method can reduce the parameters input when modeling; we can just modify the corresponding parameter to achieve the new model.Finally, this paper developed the parametric modeling and structure optimization software of the ship unloader. The software provides two functions, one is the parametric modeling function, and people can realize the ship unloader's modeling by input parameters on the interface. The other is the structure optimization function, which can realize the weight reduction target of ship unloader by the structure optimization method based on the orthogonal experimental method. Through the case study, the results show that this structure method can reduce the weight of ship unloader for 53.66tons, and reduce 2.8% of the ship unloader's total weight.