| 摘要:为更准确进行某型柴油机活塞裙服役过程的仿真分析，提出一种瞬态动力学仿真方法，旨在替代传统静态分析法。该方法通过耦合活塞-活塞销-连杆系统，施加实测缸压曲线，采用显式算法计算0°～720°曲轴转角的全过程。通过定量对比瞬态仿真与静态分析结果发现：活塞裙部最大主应力在瞬态模型中达348 MPa，较静态分析结果提高10%；应变增幅约0.5%。进一步的损伤分析表明：瞬态模型的最小安全因数为1.417，低于静态模型的1.482；预测的疲劳寿命为2.983×109次循环，低于静态模型的3.764×109次循环。结果表明，瞬态分析能够更真实地反映活塞裙在动态载荷及热机耦合效应下的力学行为，可显著提高失效风险评估的精度，为活塞结构优化和可靠性设计提供依据。 |
| 关键词: 活塞仿真 寿命预测 安全因数 瞬态分析 |
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| Piston Fatigue Life Prediction of a Marine Diesel Engine |
| Guo Xiaoyu,Wu Limin,Tang Yihu |
| Shanghai Marine Diesel Engine Research Institute， Shanghai 201108，China |
| Abstract:To achieve more accurate simulation analysis of the piston skirt service process for a specific diesel engine model，a transient dynamic simulation method was proposed to replace traditional static analysis method.By coupling the piston-piston pin-connecting rod system and applying measured cylinder pressure curves，the method employs an explicit algorithm to compute the entire process from 0°to 720° crankshaft rotation angle.Quantitative comparison of transient simulation and static analysis results reveals that the maximum principal stress on the piston skirt reaches 348 MPa in the transient model，representing a 10% increase over static analysis results，with a strain increase of approximately 0.5%.Further damage analysis indicates that the minimum safety factor in the transient model is 1.417，lower than 1.482 of static model.The predicted fatigue life was 2.983×109 cycles，lower than 3.764×109 cycles of static model.These results demonstrate that transient analysis more accurately reflects the piston skirt''s mechanical behavior under dynamic loading and thermo-mechanical coupling effects，significantly enhancing the precision of failure risk assessment.This provides reference for piston structural optimization and reliability design. |
| Key words: piston simulation life prediction safety factor transient analysis |
