Simulation of Kinematic Supports of Surfaces Plates for Optimum Flatness Tolerance

摘要

In the precise and accurate metrological activities, there are various types of surface plates (SPs) used in mounting or calibration purposes. It is essential to install surface plate in the laboratory with a minimum self-deformation and resultant least strain due to its own weight and mounting mechanism. Reference datum of the measuring machines, say in case of a pressure balance, requires flatness tolerance of the order of few microns to fraction of an mm. In another example, in case of Coordinate Measuring Machines, a large bed is used as flat surface plate mounting on air bearing. Traditionally, manufacturers use 3 or 4 pods supports in the base of such SPs. The Federal specification standards of SPs describe the location of the support pods (Federal Specification GGG-P-463c Amendment-1, 'Federal Specification: Plate, Surface, (Granite) (Inch and Metric)', June 1977). However, the optimization of the location of these support systems, number of pods used and self-weights of the SPs are still unexplored. In the present investigation, authors have made focused efforts to design, simulate and analyze the SPs using design and simulation tools such as SolidWorks and Ansys for the range of thickness under the self-weight conditions. Various configurations of kinematics support on the different materials such as granite and stainless steel plates have been studied and analyzed. The computational FEA studies carried out on the SPs show that the behavior of the deformation pattern over the SP changes significantly as a function of thickness of the plate. The results thus obtained are discussed in details.