Study On Optimal Design Of Thermal Barrier Ceramic Coating Piston Based On Topology Optimization

Piston,as the "heart" of engine,works in harsh environment with high temperature and high pressure and its structure and performance will directly affect the engine life and efficiency.Aiming at the problem that the temperature of the diesel engine piston is high,which leads to the decrease of the mechanical properties of the material,the method of applying the ceramic on the top surface of the piston has been carried out to study the temperature and stress analysis of the thermal barrier ceramic coating.Against the problem of the heavy piston is not suited to the development direction of modern engines and leads to the greater inertial force,the method of topology optimization is used to studied the lightweight.Finally,the problem of high temperature and heavy quality is solved.Firstly,the three-dimensional model of the piston is established in Pro/E.The boundary conditions of the steady-state temperature field are obtained by the combination of experiment and theory,at the same time,the temperature and thermal stress distribution of the piston are also obtained.Then,in order to reduce the temperature of the piston substrate,a three-dimensional model of the thermal barrier ceramic coating piston is established and the three-dimensional model of the thermal barrier ceramic-coated piston is established in Pro/E,and the physical parameters of different coatings are determined.The temperature field and stress field of Y-PSZ and Mg-PSZ piston are analyzed and compared.Y-PSZ was determined as the ultimate thermal barrier ceramic coating.Then by analyzing the temperature field and stress field of 0.2mm,0.4mm,0.6mm,0.8mm and 1.0mm five different thickness coated piston,considering the actual work of the piston,the final ceramic coating thickness is fixed to be 0.6mm.After that,the statics analysis of the piston is completed,the skirt deformation is obtained when the piston is subjected to the mechanical load.Then,the deformation is used as the constraint condition,and the topology optimization model of the piston lightweight is established and the software of OptiStruct is used to complete Topological iteration calculation.Considering the assembly and production crafts of the piston,the piston model of the optimized topology is obtained,and the optimized piston mass is reduced by 8.88%.Finally,the finite element analysis of the optimized piston is carried out.Comparing with the original piston temperature,stress and deformation,the stress is still within the material yield strength,and the deformation is very similar to the original piston.The feasibility of piston topology optimization is verified,which lays of a foundation for the optimization topology of other piston.