Corrosion Fatigue Life and Reliability Analysis of Blade Root Bolt of Ship Controllable Pitch Propeller
The blade root bolt,as a key component in the controllable pitch propeller device,plays a very important role in the safe and reliable operation of the controllable pitch propeller.Due to the harsh working environment and complex loads,a large number of stress corrosion fatigue fractures occur in blade root bolts during operation,which poses a serious challenge to the safe and reliable operation of the adjustable pitch propeller device.An evaluation method for the corrosion fatigue life of blade root bolts is established based on the existing load spectrum of blade root bolts,combined with the initial crack and crack propagation models.The input variables are selected and quantified,and a blade root bolt corrosion fatigue life analysis model based on Monte Carlo(MC)method and Adaptive Kriging-based Monte Carlo(AK-MCS)method is proposed.The fatigue reliability and sensitivity analysis are carried out,and the global sensitivity of reliability and random variables is calculated.The results show that under the condition of 100％maximum continuous rating(MCR)pitch ratio,the corrosion fatigue life of the blade root bolt is 4.84 years when the pitch control propeller remains in working condition.The corrosion fatigue reliability of the blade root bolt calculated by the AK-MCS method is 0.954 1,which has a smaller error compared to the MC method.Compared with the calculation amount,the MC method calls the functional function 105 times,while the AK-MCS method calls it only 73 times,resulting in an increase in calculation efficiency of 1,368.9％.The top three factors affecting the corrosion fatigue reliability of blade root bolts in the input variables are hydrogen concentration,bolt preload force and bolt root stress concentration factor.
万方数据
维普
