INVESTIGATION OF FINITE ELEMENT THERMAL MODELS FOR WORKPIECE TEMPERATURE IN CYLINDER BORING

摘要

The accuracy and computational efficiency of four finite element thermal models for workpiece temperature in cylinder boring are studied. High temperature in precision cylinder boring of automotive engine block can distort the workpiece, leading to thermally-induced dimensional and geometrical errors. In cylinder boring, the depth of cut is small compared to the bore diameter, so a fine mesh is usually needed to analyze the workpiece temperature distribution; however fine mesh on a relatively large workpiece also takes extensive computational resources. To understand the trade-off between accuracy and computational efficiency, the advection, surface heat, heat carrier, and ring heat finite element thermal models are introduced and compared quantitatively in a boring process. It is found comparable global temperature estimation from all four models. For the temperature near the cutting zone, the advection and surface heat models are more accurate to predict local temperatures but consume more computational resources. The heat carrier model predicts the surface temperature with reasonable accuracy and computational time. The ring heat model is the most computationally efficient but fails to accurately estimate local peak temperatures.