Abstract

In an internal combustion engine, a piston rod joins a piston to the crosshead and thus to the connecting rod that drives the crankshaft. Thus, the most responsible elements in internal combustion engines are the piston, piston rod and crankshaft group. Within this group, the piston rod is an element of great importance given the high loads it is subjected to. In the process of constructing the piston rod, it is important to accurately determine the distribution of stresses and deformations, defining its optimal shape so that no fracture occurs during operation. In this paper, the fracture conditions of an internal combustion piston engine due to accidental damage were analyzed. Based on the forces acting on the piston rod, a stress distribution is determined throughout the piston rod. The effect of damage on the piston rod beam on fracture occurrence was analyzed considering the principles of linear elastic fracture mechanics. On the basis of the obtained research results, the impact of the crack length was quantified and recommendations for improving the design of the piston rod were made.