Statistical analysis and modeling of temperature distribution during various milling operations of thin walled aircraft parts

Skin panels are one of the most important components constituting the aircraft structures such as wing and fuselage sections. These thin-walled components were produced from 2024-T3 aluminum alloys and many pockets were usually created in these panels by chemical milling process for weight reduction purpose. However, this process is time consuming due to its slow metal removal rate, its health hazard and its severe significant environmental impact. End-milling could provide an excellent base for creating the panel pockets and maintain the required precision. Nevertheless, maintaining a comparable quality between the two processes is quite challenging due to the dynamic nature of the cutting process and the heat generating during machining. Furthermore, an overheating in the cutting zone generally induces structural variations of the material texture, involving residual stresses and reduces stiffness which leads to damages in the machined panels. In this paper, the effect of cutting conditions on heat generation was investigated experimentally based on Taguchi and full factorial design techniques. A quantitative and qualitative statistical analysis is used to identify relationships among heat generation and process parameters, heat generation and cutting region and finally, heat generation and machining operation. The results showed that the proposed approach can successfully detects the significance or non-significance of the temperature variation between different cutting zones and machining operations.