Thermomechanical Fracture Failure Analysis of a Heavy-Duty Diesel Engine Cylinder Liner through Performance Analysis and Finite Element Modeling

Diesel engines include systems for cooling, lubrication, and fuel injection and contain a variety of components. A malfunction in any of the engine systems or the presence of any faulty element influences engine performance and deteriorates its components. This research is concerned with the untimely appearance of vital cracks in the liners of a turbocharged heavy-duty Diesel engine. To find the root causes for premature failure, rigorous examinations through visual observations, material characterization, and metallographic investigations are performed. These include Scanning Electron Microscope (SEM) and Energy-Dispersive Spectroscopy (EDS), fracture mechanics analysis, and performance examination, which are also followed by Finite Element Modeling. To find the proper remedy to resolve the problem, drawing a precise and reliable picture of the engine’s operating conditions is required. For this purpose, the engine’s subsystems, including fuel injection, turbocharging, cooling, and power transform system, are simulated by using GT-Suite engineering software. This is accompanied by the analysis of the liner based on fracture mechanics. The simulation output is validated with some measured data from a test cell that is then used in addition to some calculated loads for analyzing the liner through the finite element method (FEM). It is concluded that 95 percent of the total stresses within the cylinder liner structure is due to the thermal loading. Also, fracture mechanics and fatigue safety factor examinations on the cylinder liner revealed that phenomena such as cavitation and corrosion in the presence of design shortcoming provide origins for crack nucleation and propagation that lead to fractures.