Iterative surface warping to shape craters in micro‐EDM simulation

This paper introduces a new method for simulat- ing the micro-EDM process in order to predict both the tool’s wear and the workpiece’s roughness. The tool and workpiece are de ned by NURBS patches whose shapes result from an iterative crater-by-crater deformation technique driven by physical parameters. Through hundreds of thousands of local surface warping, the method is able to compute the global as well as the local shapes of the tool and workpiece. At each step, the warping vector and function are computed so as to be able to generate a spherical crater whose volume is also controlled. While acting very locally to simulate the real physical phenomenon, not only the method can evaluate the tool’s wear from the overall nal shape at a low resolu- tion level, but it can also estimate the workpiece’s roughness from the high resolution level. The simulation method is validated through a comparison with experimental data. Dif- ferent simulations are presented with an increase in compu- tation accuracy in order to study its in uence on the results and their deviation from expected values

Computer-aided Micro-EDM die-sinking tool design optimisation

This paper describes a new efficient method for computer aided optimisations of micro EDM die sinking tools, which can be used for design optimisation and performance verification in the digital domain. This would facilitate the integration and re-configurability of the micro EDM die sinking process in high value products manufacturing chains. An EDM simulation tool which makes use of voxels embedded in a voxel octree to represent the geometries is introduced and its application to a new Micro-EDM die-sinking tool shape optimisation is then described. Simulation results obtained with simple shapes are then discussed highlighting the capabilities of the new optimisation method and potential areas of improvement are proposed

Iterative surface warping to shape craters in micro-EDM simulation

This paper introduces a new method for simulating the micro-EDM process in order to predict both the tool’s wear and the workpiece’s roughness. The tool and workpiece are defined by NURBS patches whose shapes result from an iterative crater-by-crater deformation technique driven by physical parameters. Through hundreds of thousands of local surface warping, the method is able to compute the global as well as the local shapes of the tool and workpiece. At each step, the warping vector and function are computed so as to be able to generate a spherical crater whose volume is also controlled. While acting very locally to simulate the real physical phenomenon, not only the method can evaluate the tool’s wear from the overall final shape at a low resolution level, but it can also estimate the workpiece’s roughness from the high resolution level. The simulation method is validated through a comparison with experimental data. Different simulations are presented with an increase in computation accuracy in order to study its influence on the results and their deviation from expected values

Estimating the exchanged energy distribution in micro-EDM

This paper presents a new approach for the recording of the total quantity of energy exchanged during the micro Electro Discharge Machining (EDM) process. In particular, this approach allows for the estimation of the percentage of energy absorbed by the two electrodes (tool and workpiece) using a combination of theoretical models and experimental results, thanks to an advanced discharges measuring approach. The validity of several theoretical crater models was then assessed. Using this approach, the process was analysed for two electrode shapes and two sets of machining parameters. The preliminary results appears to fit those presented in the literature

Computer-aided Micro-EDM die-sinking tool design optimisation

This paper describes a new efficient method for computer aided optimisations of micro EDM die sinking tools, which can be used for design optimisation and performance verification in the digital domain. This would facilitate the integration and re-configurability of the micro EDM die sinking process in high value products manufacturing chains. An EDM simulation tool which makes use of voxels embedded in a voxel octree to represent the geometries is introduced and its application to a new Micro-EDM die-sinking tool shape optimisation is then described. Simulation results obtained with simple shapes are then discussed highlighting the capabilities of the new optimisation method and potential areas of improvement are proposed

Micro-EDM numerical simulation and experimental validation

This paper introduces a new method for simulating the micro-EDM process in order to predict tool wear. The tool and workpiece are defined by NURBS surfaces whose shapes result from an iterative crater-by-crater deformation technique driven by physical parameters. The simulation method is validated through a comparison with experimental data. Different simulations are presented with an increase in computation accuracy in order to study its influence on the results and their deviation from expected values

Using voxels in the simulation of manufacturing processes

The present paper introduces the use of voxels embedded in an octree structure in order to numerically simulate manufacturing processes. In particular, micro electrical discharge machining (μEDM) is used here as a case study. The involved elements (tool and workpiece) are modelized in a volumetric manner using voxels and the process is simulated on a step-by step basis. Comparisons using the Hausdorff metric with experimental results are included and discussed

Estimating the energy repartition in micro electrical discharge machining

This paper presents a new approach for the recording of the total quantity of energy exchanged during the micro electrical discharge machining (EDM) process. In particular, this approach allows for the estimation of the percentage of energy absorbed by the two electrodes (tool and workpiece) using a combination of theoretical models and experimental results, thanks to an advanced discharges measuring approach. An experimental campaign was executed on a Sarix SX200 micro-EDM machine with a tungsten carbide tool electrode. In particular, the process was analyzed for two different electrode shapes, a triangular and a rectangular based parallelepipeds, and two sets of machining parameters. After the execution of the experimental campaign it estimate the total amount of energy that occurred during the entire die sinking process. The energy effectively lost into the tool, into the workpiece and into the dielectric was estimated from the measurement of the volume of material actually removed both from the tool and from the workpiece. The preliminary results appears to fit those presented in the literature and the validity of several theoretical crater models was then assessed. The validation of the presented acquisition method could enable the use of information related to energy repartition in the simulation of the micro-EDM process.The reported research was partly funded by the Engineering and Physical Sciences Research Council (EPSRC) under the grant EP/J004901/1