The Prediction Of Multidirectional Carbon Fiber Reinforced Polymer Composites Milling Forces

Due to the excellent properties of high specific stiffness, high specific strength, fatigue resistance and corrosion resistance, carbon fiber reinforced plastic composites (CFRP) have been widely applied to the industries of aerospace etc. in recent years. Because the flexible machining trajectory and high efficiency of milling, it has been widely used in the processes of CRPP manufacturing. Due to the CFRP is the representative material of anisotropic, the induced damages are sensitive to the milling forces, and the overlarge forces are easy to induce damages such as delamination and edge breakage, so is the key problem to predict and control CFRP milling forces.This paper researches the milling process of CFRP by the methods of theoretical analysis and experiment research, first, an BP neutral network model to predict the unidirectional CFRP (UDCFRP) milling forces are established, and then analysis the relationships between the multidirectional CFRP milling forces and the single layers, and established a model to predict the milling forces of multidirectional CFRP by the method of superposition, the main contents are described below:First, the unidirectional CFRP milling experiments are conducted and the milling forces signals are acquired and analyzed. Based on the relations of milling forces signals and the milling processes, the milling forces coefficients data and the relations with the fiber cutting angles, uncut chip thickness and cutting speed are acquired. Then the BP neutral network is established to predict the milling force coefficients, and the validation experiments results show the prediction accuracy is over 85%.Secondly, by considering the lamination of MDCFRP, the method to superpose the UDCFRP milling forces to calculate the MDCFRP milling forces is optimized. By observe the subsurface damages and the machined surface, it can be concluded that the strong support make the cutting state of 90° and 135°single layer change, which milling forces decrease. So, the support of 90° and 135°single layer can be divided into two cases:one side incongruous support and two sides incongruous support, and the corresponding optimized coefficients are acquired by the MDCFRP milling experiments.In the end, based on the BP neutral network and the optimized superposition method, the model to predict the MDCFRP milling forces are established. The validation experiments results show that the model can accurately predict the MDCFRP milling forces.