Simulation analysis of the circular sawing process of medium density fiberboard (MDF) based on the Johnson–Cook model

Medium density fiberboard (MDF) is a commonly used engineered wood product. Sawing is a key process in MDF usage. In this study, a Johnson–Cook constitutive model for two types of MDF under high-speed impact was developed, and a simulation model for the circular sawing process that calculates cutting forces under different process parameters was created. The accuracy of the simulation model was verified through sawing experiments and the effects of cutting speed, feed per tooth, and saw blade position on cutting force and surface roughness were analyzed. The results indicate that MDF prepared with poly 4,4′-diphenylmethane diisocyanate (pMDI) has better mechanical properties than MDF made with urea–formaldehyde (UF) resin, leading to greater cutting force and surface roughness during processing. The cutting surface roughness and cutting force are positively correlated with the cutting speed and feed per tooth, and the excessive cutting speed leads to the cutting system’s vibration, which makes them increase more obviously. Increase the distance between the rotation axis of the saw blade and the workpiece results in more sawteeth participating in the cutting process, which increases the cutting force but also reduces the axial force fluctuation and the surface roughness.