Computer simulations for burr formation study

Burrs are one of the most serious obstacles to precision manufacturing and manufacturing process automation. No satisfactory model exists for burr formation prediction. A computer simulation method is proposed for burr formation study.; An Eulerian/Lagrangian finite element model (the Eulerian FE model) was developed for the burr formation simulations. This model uses Eulerian elements to model the workpiece and Lagrangian elements to model the cutting tool. The explicit time integration scheme is the solution procedure used. Because the characteristic length of the workpiece and burrs are several orders of magnitude apart, high mesh density is required and large computing resources are needed. Guidelines are given regarding finding reasonable element number of the model so the simulations can be run with limited computing resources.; The orthogonal cutting model is a well studied and well known metal cutting model and is an ideal test case for the model. An orthogonal cutting model was simulated using the Eulerian FE model. The simulation results are reasonably good in both the stable cutting stage and burr formation stage.; A face milling simulation was run using the Eulerian FE model. The concept of exit order sequence (EOS) has been proposed to assess the burr formation mechanism. This simulation was able to predict the burr formation according to the EOS categories.; The complex drill bit geometry has been an obstacle for the finite element simulation of the drill processes. A geometry model of conventional type drill bit with chisel edge was developed. A finite element mesh generation algorithm based on the drill bit geometry was developed. A sample implementation of the algorithms was written.; A drilling process simulation was run using the Eulerian FE model. The finite element meshes of the drill bit generated by the algorithms developed were used in this simulation. The crown type burr observed experimentally was predicted by this simulation.