Numerical modelling of deep rolling influence over crankshaft bending and correlation with fatigue behaviour

Abstract

The requirements for mechanical reliability of automotive crankshafts are continuously increasing, thus pushing the demand for an optimized processing. Nonetheless, the manufacturing‐induced residual stresses at critical sites for fatigue enhancement are not clarified in the state‐of‐the‐art on the topic. In particular, there is a lack of information on the effect of final manufacturing stages to improve the component life endurance, such as deep rolling, in the overall stress state while the component is under operational loads. This study deepens the validation of a finite element deep rolling model under development with the aid of an in‐house developed crankshaft resonance fatigue test rig. The stress state obtained from the deep rolling simulation was input as a predefined stress field for the simulation of operational conditions experimented at the test rig. Test results produced cracks at the fillet radii of the cast iron crankshafts as anticipated. Overlapping the fractography with the simulation's final stress field yielded interesting correlation with the crack morphology. This contributed with a strong indication of the model correctness. Moreover, it can be further implemented to indicate whether the process parameters such as roller force and angle are fully optimized for each particular crankshaft application.

Crack propagation mapping at component‐level fatigue testing by means of natural frequency tracking control

“…However, the energy input by the test load was not sufficient to surpass the barrier imposed by the compressive residual stress peak exemplified by Figure 5B. More information on crankshaft residual stress data can be found in Fonseca and Faria, 37 Fonseca et al, 33 Faria et al 38 and Fonseca et al 39 The natural frequency shift, therefore, indicates the crack size.…”

“…Dye penetrant inspection and fractography of failed and non‐failed specimens. Adapted from Fonseca et al 33 [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…Crack inspection steps: nondestructive, through dye penetrant following standard ISO 3452‐1; destructive, by opening the crank throw using a hydraulic press and measuring with digital microscope DinoLite AM4013MZT. Adapted from Fonseca et al 33 [Colour figure can be viewed at wileyonlinelibrary.com]…”

Research on the Bending Fatigue Property of Quenched Crankshaft Based on the Multi-Physics Coupling Numerical Simulation Approaches and the KBM Model

“…Fonseca analyzed the influence of the manufacturing process on the residual stress, which was caused by deep rolling with the combination of the finite element analysis and the corresponding fatigue tests. The research results could provide the theoretical basis for the optimization design of the process [17,18]. Antunes analyzed the finite element meshes for optimal modeling of plasticity-induced crack closure and proposed the analytical expression of the most refined region along the crack propagation area.…”

Impact Analysis of Initial Cracks’ Angle on Fatigue Failure of Flange Shafts

“…However, some obstacles remain: first, it needs to be checked whether the S-N curve of various weld details is suitable for new steel; secondly, making S-N curve requires previous load information to predict the fatigue life of the structure details, but the historic information is difficult to acquire, let alone determine the fatigue life; third, this method cannot assess the remaining life with the flange's test data, such as the distribution and size of the crack. In recent years, the method that combines fracture mechanics with finite elements has developed rapidly and become one of the main tools in the research of fatigue crack [2][3][4][5][6][7]. Atanasovska et al carried out finite element analysis of corrosion fatigue crack and turbine shaft damage based on actual turbine shaft failure cases and proposed a new method to calculate the stress concentration coefficient [8].…”