STRUCTURAL-ANALYSIS OF CYLINDER HEAD CRACKING IN A HEAVY-DUTY DIESEL-ENGINE

There were fatigue cracking problems at the intake ports of a prototyp e heavy-duty six-cylinder head. Several proposals of design change wer e evaluated by finite element and reliability analysis. Constant ampli tude loading and monotonic temperature-dependent properties of the hea d material are assumed. An equivalent stress-strain parameter (ESSP) i s proposed to consider multiaxial stress/strain effect on fatigue crac king. A significant reliability improvement was predicted with cost sa vings and verified by limited engine tests.