Structure Optimization Design Of The High Power Fracturing Truck Frame

As the key equipment of oil field fracturing, fracturing truck is used for high pressure and large capacity stimulation operations with great weight of vehicle equipments and poor road conditions. As the main load-bearing component, the frame should bear not only the load of bending, torsion and vibration caused by road irregularities but also the larger impact load produced by fracturing pump during fracturing. To ensure the safety and stability of the whole vehicle, sufficient strength, rigidity and good dynamic performance are required. The frame of fracturing truck is taken as research object, topology and size optimization design and performance analysis are conducted based on the theories and methods of structural optimization. Meanwhile, the structure optimization design system of frame is developed to realize the intelligent of design process.According to the requirements of frame structure design, multi-objective topology optimization is carried out based on SIMP variable density method, with static stiffness under multiple working conditions and low order natural frequencies comprehensively considered.The mathematical model is established with weighted compromise programming method adopted to define multi-stiffness objective and mean frequency method used to define dynamic frequency objective. The optimal topology of frame which meets the multi-stiffness and dynamic characteristics requirements is obtained and the frame structure is preliminarily designed based on the optimization results.On the basis of structure topology and preliminary design, size optimization of the frame is conducted with the application of ANSYS parametric design methods. Parameters with great influence on the performance of frame structure are chosen as design variables of size optimization on account of the sensitivity analysis results. The basic location of optimal solution is obtained by sub-problem approximation method provided by ANSYS and the accurate solution is acquired after first order optimization. Performance comparison demonstrates that the properties of the frame after optimization are significantly improved.To avoid repetitive work and improve design efficiency, the structure optimization design process for fracturing truck frame is standardized and optimization system is developed based on Visual Basic platform. The automation of topology optimization design process and dimensional parametric design as well as finite element analysis are realized respectively through secondary development of HyperMesh and calling ANSYS in the background based on APDL. The application shows that the system is convenient, reproducible and able to achieve rapid optimization design, providing parametric design reference for similar products.The analysis results indicate that structure performance and load capacity of the optimized frame are increased, providing an effective method for structure optimization design of frame.