Optimization of drilling process on corrugated core sandwich panels

The objective of this work is to investigate the influence of cutting speed (rpm), feed rate (mm/min) and tool diameter (mm) on the uncut fiber and delamination damage of a type of composite sandwich structures including PVC foam, Trapezoidal corrugated sheets and faces made of E-Glass/polyester. VARTM method has been used for manufacturing of samples. A design of experiments (full factorial) was used to assess the importance of the drilling parameters. The drilling operation was assessed based on two introduced factors including the delamination factor (DF) and uncut fiber factor (UCFF). Minitab software has been used for obtaining the role of each parameter on output factor. Analysis of the experimental results for DF indicated that the feed rate and drill diameter were the most significant and insignificant parameters, respectively. But, experimental results for UCFF showed that the tool diameter has greatest influence where UCFF increased with increasing diameter, too. Also, the results revealed that the both factors increase with the increase of feed rate. There is an optimum point for cutting speed and tool diameter in evaluation of UCFF. Whereas, increasing tool diameter leads to decrease of DF and generally there is a maximum point in variation of cutting speed for UCFF.