A subjective-objective evaluation method of hole surface quality in drilling CFRP-Ti stacks

Abstract

Hole surface quality in drilling carbon fiber-reinforced plastics and titanium alloy (CFRP-Ti) stacks is a key factor affecting high-quality assembly and reliable usage of the structure so it need be reasonably evaluated. However, there is no standardized evaluation system of hole surface quality in drilling CFRP-Ti stacks. The existing evaluation indexes cannot meet the evaluation requirements on the surface quality of the hole. This paper proposes a subjective-objective evaluation method to evaluate the surface quality of the hole in drilling CFRP-Ti stacks. Firstly, the evaluation factors are determined by experiments, including CFRP delamination, CFRP hole entrance tears, surface roughness of CFRP and Ti, and the evaluation system is established according to defect characteristics and industry standards. Secondly, the subjective evaluation model is established based on the improved analytic hierarchy process, the objective evaluation model is established based on the entropy weight method and the subjective and objective combination weight calculation method is obtained based on the principle of minimum discriminant information. Finally, the surface quality of the hole is evaluated by subjective, objective, subjective-objective evaluation methods respectively. The result shows that subjective-objective evaluation method is more reasonable and effective.

Synthesize evaluation method of characteristic defects in hole drilling of carbon fiber reinforced polymer

“…The judgment matrix (JM) can determine the weights of multiple factors overall by comparing the factors in pairs. This is crucial in the multi-factor decision-making and comparison problems in various fields [15,16]. Commonly used JMs include a complimentary judgment matrix (CJM) and reciprocal judgment matrix.…”

Application of ANN for Analysis of Hole Accuracy and Drilling Temperature When Drilling CFRP/Ti Alloy Stacks

“…To ensure the proper service life of joints, the drilled holes in FRP/metal stacks must satisfy certain quality parameters [ 6 , 7 ]. These quality parameters are hole diameter [ 8 , 9 , 10 , 11 ], roundness and cylindricity [ 12 , 13 ], surface roughness [ 14 , 15 , 16 ], delamination factor ( F d ) [ 8 , 14 , 17 , 18 ], thermal destruction [ 19 ] and damage value ( Q d ) [ 20 ], and burr height for Ti alloy [ 21 , 22 , 23 ]. Milentiev et al reported the connection between tool geometry and process parameters on delamination factor in CFRP [ 24 ].…”