| In order to solve the difficulty of obtaining the soil resistance during the excavation process and improve the research on hydraulic excavator’s soil-transferring efficiency,the author used arbitrary Lagrangian-Eulerian algorithm(ALE)to carry out numerical simulation of soil resistance.With the help of Computer Aided Engineering and mathematic methods,the time consumption of excavation process was obtained.The efficiency of excavation process was improved by the optimization of hydraulic excavator bucket through orthogonal experiment and surrogate model technology by taking the bucket capacity and excavation time consumption ratio as a measure.The thesis illustrates the research background and the meaning of the research,introduces some research progress about the thesis.The numerical simulation of soil resistance of typical excavation process based on ALE was carried out.Through the establishment of virtual prototype of hydraulic excavator,the pressure of the cylinders of excavator was obtained and validated correct by comparing with real experimental data.The time consumption calculation of typical excavation process that takes the influence of soil resistance in the excavation process into consideration was carried out based on the hydraulic pressure variation history obtained before and the hydraulic system parameters of the excavator.Through orthogonal experiment,the law of influence of the bucket structure on the excavation efficiency and some buckets with better efficiency than the original one were obtained.Response surface surrogate model which takes the structural parameters of bucket as the design variables and the excavation efficiency as response was established and its accuracy was validated by Latin hypercube sampling method.Through differential evolution algorithm,the optimal bucket was obtained by optimization of the surrogate model,and validated by experiment.The last part of the thesis summarizes the thesis and prospects for the follow-up work. |
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