Design analysis of machine tool structure with artificial granite material

Artificial granite material has been used for construction of the high-precision machine due to superior damping ability. However, its lower material stiffness also lessens the application in fabrication of the machine tool. The purpose of this study was therefore aimed to verify the structure performance of the machine tool reformed with artificial granite material, instead of the casting iron. To gain insight into the optimized configuration of the vertical columns and spindle head stock, the static and dynamic characteristics of the machine models with cast iron and granite composites were predicted for comparison. With this, evaluations of the machine with different design were made to examine the experimental measurements on the prototype machine. According to the simulation results and experimental measurements, the static stiffness of the machine tool reformed with granite material is comparable to the original casting machine, differed by 8% approximately. However, granite machine shows superior dynamic stiffness, about 0.5-1.3 times of the conventional casting machine. This study verifies the feasibility and effectiveness in fabrication of the machine tool with the artificial composite material and provides the improvements for further fabrications.