8NVD48A-2U柴油机曲轴的断裂力学分析和实验研究

A Fracture Mechanics Analysis and Experimental Investigation on Crankshaft of Model 8NVD48A-2U Marine Diesel Engine

根据断裂力学原理，采用三维力学模型实验和新兴的焦散线法，对8NV－D48A－2U型柴油机曲轴的三维应力状态、断裂为学参数进行了分析和实验研究，以预报曲轴安全可靠性和寿命，为船舶检验周期提供理论和实验依据。并提出曲轴表面裂纹几何因子的表达方法和曲轴裂纹扩展速率的表达式，对Paris经验公式进行修正。

Based on the phinciple of fracture mechanics an analysis and investigation on 3-D stress state and fracture mechanics parameters of the crankshaft of model 8NVD48A-2U diesel engine has been made by using 3-D mechanics experimental model and the caustics method, for purpose of predicting the safety, reliability and working life of the crankshaft and providing the ship examining cycle with theoretical and experimental bases. In this paper, a method for representing geometric factors of the crankshaft surface crack and an expression for the crankshaft crack propagation rate are proposed. The Paris empirical formula is also revised.