Study On Service Mechanical Damage Mechanism Of Glass Fiber Reinforced Plastics With Wind Blades

This thesis analyzed the service performance of glass fiber composite wind turbine blade propellers.Since propellers were subjected to different forms of damage in long-term service in harsh environments,specific studies on strength,modal analysis,structural static analysis and buckling analysis of propellers were required.This thesis focused on the following research:(1)Analyzed the related literature at home and abroad,study the crack damage condition of the propeller in service,and established the finite element model of the propeller.The finite element simulation analysis of the propeller was carried out by using Solid Works 2022 software,mainly including the variation of equivalent force,equivalent elastic strain and total deformation.(2)The design radius R of 37.5m of the propeller,the allowable stress[σ]was 170MPa,the rated wind speed was 12m/s,the maximum wind speed is 25m/s,the tower height H was 70m,the tip ratioλis 7,the cut-in speed is 3m/s,the cut-out wind speed v was 25m/s,the number of the blades B was 3,the air densityρis 1.225kg/m~3,the limit wind speed was50m/s and the rated speed was 12r/min.The wind pressure formula obtained by Bernoulli equation was P=0.5ρv~2,and the wind pressure characteristics of the blade could be obtained.According to the calculation,the wind pressure P=1531.25Pa at the ultimate wind speed of 50m/s.The finite element analysis could be divided into two categories,one was modal analysis and the other was structural static analysis,and this method could provide new ideas for twisted blade propeller modeling.(3)By using ANSYS Workbench 2020 R2 software,the numerical simulation was performed by applying the corresponding boundary conditions of wind load,rotational speed,ground support force and fixed constraints to the propeller model,which provided an important reference for the subsequent simulation analysis.(4)Static finite element analysis of the propeller structure,by using ANSYS Workbench 2020 R2 software,structural static simulation analysis was carried out for the propeller with and without prefabricated cracks,including the cases of equivalent force,equivalent elastic strain and total deformation,and the strength and stiffness of the propeller were strictly checked according to the relevant regulations to ensure that the strength and stiffness of the propeller conform to the relevant standards and thus meet the design requirements.(5)The safety of the blade propeller was studied by using Abaqus CAE software to perform buckling analysis to assess its reliability and operational stability,and to better predict and control instability in the event of adverse loads.