Strength analysis of diesel engine block based on multi-body transient dynamics

Abstract

Based on the multi-body transient dynamics calculation method, the strength of a low-speed marine diesel engine block is analyzed. Firstly, UG software is used to simplify the whole machine and obtain the corresponding simplified model. Then, in ANSYS software, the corresponding loads and boundary conditions are applied to each component in the diesel engine model to simulate the normal working process of the diesel engine and calculate the structural strength of the engine block. It is found that the stress on the engine block is not constant, but changes with the rotation of the crankshaft and the explosion of each cylinder. The position of the maximum stress on the engine block appears at the bolt hole on the upper surface of the cylinder block, and is far less than the tensile yield strength of the material. Finally, the fatigue life of the computer block is calculated by importing three elements: stress distribution data, material properties and load spectrum. It is found that the mechanical fatigue life time of the engine block is much longer than the overhaul period of the diesel engine, which can be considered as infinite life.