Thermo-mechanic Coupling Analysis And Experiment For Gasoline Engine Piston

As a key part suffering harsh conditions in the reciprocating engine, the working stateof piston relates directly to the dependability and durability of the engine as well as theeconomy and emission performance. Under operating, on the one hand the piston bears hightemperature due to the high temperature burning gas, which also leads to nonuniformtemperature distribution, heat deformation and heat stress on the piston. On the other hand,the piston suffers mechanical stress and deformation because of the inertial force andperiodic gas pressure. Therefore, it is essential for proposing and evaluating improvementapproach and reinforcing piston to analyze the temperature field and heat stress field,andconduct a thermo-mechanical coupling research.To analyze the stress under thermo-mechanic load, figure out temperature field andevaluate the influence of Anodic Oxidation Coating on thermal load of the piston, hard-plugtemperature-measured experiment and computer simulation method were used in this paper.To gain specified pionts’ temperature value on the piston when the engine is running underrated condition, bench experiment was carried out with piston installed with hard-plugs.These plugs’ hardness were measured after the experiment and converted to temperaturevalue according to the Hardness-temper Temperature Curve (HV-T Curve). The HV-TCurve of the hard-plug which is made of GCr15-bearing steel was drew through hardnessmeasure under different temper temperature.In this paper3D model and mesh model were built with the help of software Pro/E andHypermesh in first. Then a FE model which can describe the real temperature fieldprecisely was built by Abaqus software. This FE model covers mechanic boundaries andheat boundaries verified by experimental data. The simulation results—two piston’stemperature field, heat stress field, coupling stress field, showed that: the simulation resultscoincide with experimental well with a less-than-5%relative error, the overall temperatureand heat stress of the piston with coating decreased substantially compared with the originalone, while the coupling stress decreased slightly. This suggests that Anodic OxidationCoating on piston plays a positive role in lowing heat load of piston.