Towards the Development of a Novel Smart Work-holding Fixture for Advanced Manufacturing

This work highlights the initial development phase of a smart fixture that can monitor the workpiece temperature to mitigate thermal errors contributed through the work holding fixture. In machining processes, the friction generated heat by the tool-workpiece interface gets transferred to the fixture which causes thermal expansion in both the workpiece and the fixture. It has been identified that the thermal expansion of the workpiece holding fixture also contributes to further exacerbate the overall thermal accuracy of the workpiece. A Finite Element Analysis (FEA) based modelling technique was utilised for the determination of workpiece thermal deformation whilst in a work-holding system. To replicate cutting trials, controlled heat experiment was conducted where an aluminium workpiece has been considered constrained in the work holding fixture. The results from experiments were used to calculate input parameters for FEA simulations. Temperature flow directions and gradients were considered to ensure experimental gradients match simulated gradients which led to further validate both experimental and simulated thermal deformation results. The results suggested a good quantitative agreement with averaged temperature accuracy of 94.28% and thermal deformation accuracy of 89.27% in the X-axis direction and 94.98% in the Y-axis direction.