This study establishes a kinematics model, elastic deformation model, and plastic accumulation model of a single grinding wheel, simulates the grain distribution on the surface of the common grinding wheel by using the grain vibration method, and examines the effect of different grinding parameters on the surface topography of the workpiece. Results show that the peaks and valleys on the profile curve of the workpiece surface increase, and the corresponding Ra and Rz heights decrease, as the peripheral velocity of the grinding wheel increases. The peaks and valleys on the profile curve of the workpiece surface decrease, and the corresponding Ra and Rz heights increase as the feed speed of the workpiece increases. Experiments are conducted to verify the simulation results. The results show that the simulation method can predict the surface roughness of the workpiece, which is a factor in selecting the grinding parameters.
Top16.1 Introduction
There are mainly two researches method on formation process of surface morphology: experimental method and modeling and simulation method Ekberg et al. (2019) and Shi et al. (2019). A great number of machining experiments are needed in the experimental method, and this method can only be used to study the finally generated workpiece surface morphology and it’s difficult to reflect material removal mechanism in the machining process; modeling and simulation method realizes modeling of the machining process, comprehensively analyzes influences of various parameters on machining process, reveals removal mechanism and shorten experimental time. Surface roughness is an important parameter evaluating workpiece surface morphology. Establishing the relationship between grinding parameter and surface roughness will be of certain guiding effect on optimization of grinding parameters.
Domestic scholars and institutions have conducted certain theoretical and experimental research work for predicting workpiece surface morphology generation and surface roughness.
Onishi et al. (2014) from Suhzou University and his team conducted computer simulation of workpiece surface morphology generation in the grinding process, established a related mathematical grinding model and completed simulation of morphology generation process of workpiece surface in the surface grinding using MATLAB software. Material parameters and grinding parameters were considered in the simulation, but randomness of abrasive grains on grinding wheel surface was not fully taken into consideration in the simulation of grinding wheel.
Hong (2000) from Hongkong Polytechnic University established a 3D workpiece surface morphology model related to precision machining simulation. This model considered influence factors of workpiece surface morphology like geometric shape of tool, interference between tool and workpiece and cutting parameters, morphology generation of workpiece surface was simulated and experimental verification was implemented. Results showed that workpiece surface morphology generated by this model was consistent with that obtained through the experiment.
Chen (2010) from Tianjin University generated grinding wheel surface morphology using Johnson transform and linear filter technique, realizes simulation of generation process of workpiece surface morphology through precision grinding under different morphologies of grinding wheel and different machining conditions and verified correctness of surface morphology generation algorithm.
Hao et al. (2013) from Jilin University established relating grinding models based on time response, including grinding force model, grinding heat model and surface roughness model, through which generation process simulation of workpiece surface morphology was simulated and workpiece surface roughness was predicted. The model could be of a certain guiding effect on selection of grinding parameters and prediction of grinding quality.
Gong et al. (2002) from Northeastern University used virtual simulation technology, C++ programming language and OpenGL graphical tool to realize generation process simulation of workpiece surface morphology under surface grinding and built a simulation platform for surface morphology generation. Spherical abrasive grains were used on grinding wheel surface in this method, and influences of grinding wheel parameters and grinding parameters on surface morphology generation were considered. Su et al. 2008) used the same method to realize generation process simulation of surface morphology and investigated the relationship between different grinding parameters and workpiece surface roughness, and the only different was that abrasive grains used on grinding wheel surface in this simulation were cubes with different arrangement directions.
Foreign scholars have carried out a large quantity of theoretical and experimental studies on prediction of morphology generation and roughness of workpiece surface.
Sakakura et al. (2008) measured section profiles of 50 abrasive grains as standard abrasive grains which are randomly distributed on the surface of grinding wheel, and implemented digital simulation of grinding wheel morphology. In consideration of elastic deformation of abrasive grains, this grinding wheel was used to complete simulation of generation process of workpiece surface morphology in the cylindrical grinding process, and surface roughness of sampling area was calculated.