以某柴油机气缸盖为研究对象，针对其在试验过程中出现的开裂问题，利用仿真分析手段，从冷却流场、温度场、应力、变形、疲劳安全系数等多个维度对气缸盖的受力状态进行评估，以探寻导致该气缸盖失效的载荷作用机理和疲劳开裂机制。研究结果表明，仿真评估模型中疲劳安全系数最低的区域与实际使用过程中的开裂位置一致，该区域在温度载荷和气体力载荷构成的疲劳循环载荷作用下发生开裂。

For the cracking problem of cylinder head in the test process, the stress state of cylinder head was evaluated from multiple dimensions such as cooling fluid field, temperature field, stress, deformation and fatigue safety factor by means of simulation method in order to explore the load-acting mechanism and fatigue cracking mechanism leading to the failure. The results show that the area with the lowest fatigue safety factor in the simulated assessment model is consistent with the cracking position in the actual using process and it cracks due to the fatigue cyclic cracking load composed of temperature and gas force load.