The mechanism of the reduction of tapping torque by low-frequency torsional vibration tapping is analyzed. The experiments are carried out to compare the tapping torque and the service life of vibration tapping with that of continuous tapping without cutting fl uid. And the effect of cutting fl uids on vibration tapping is studied by experiments, too. It is indicated that not only the tapping torque could be reduced greatly, but also the service life of tap is extended remarkable by vibration tapping.
A supplier evaluation model with incomplete information is presented based on ameliorated analytical hierarchy process (AHP). Weight of each rule is figured out according to the algorithm of AHP in the evaluating system. Weights of the rules which cannot be quantitated are determined by the experts’ mark. The group decision-making of incomplete information can be solved through LRM (latent root method). Then an example of the problem is given.
Based on the establishment of evaluation index used in CBT aircraft maintenance system, the conversion of qualitative index to quantitative index is realized by using Fuzzy AHP synthesize evaluation method. The evaluation analytical model of aircraft maintenance system is built up to overcome the subjectivity and randomness of evaluation and to realize the scientifi c evaluation for the aircraft maintenance system. The CBT evaluation system is designed to solve the problem that there are a great deal of artifi cial mathematics in the evaluation process. The experiment shows that this kind of evaluation system can solve the evaluation problem of CBT aircraft maintenance system.
