Research On Detecting And Simulating Technology Of Plate And Shell Structure Based On FBG Sensor

The variable curvature shell structure is one of the main components of aircraft.The safety performance of the aircraft is affected by deformation during assembly.It's necessary to use effective technology to predict the deformation of plate and shell in the assembly process.The shape and size of the structural compensator is used to fill the assembly gap according to the prediction model.This completes the assembly task.In order to solve the problems of time consuming,low assembly and low precision in the assembly process of work piece with large curvature such as plate and shell.In this paper,FBG sensors are applied to monitor the deformation of plate and shell structures in a certain range of curvature.Moreover,a surface reconstruction algorithm is established to reconstruct the deformed shell.The ANSYS simulation method for predicting plate and shell assembly deformation is established by combining FBG sensing technology and ANSYS simulation technology.Firstly,the strain sensing characteristic formula and temperature sensing characteristic formula are derived by the working principle of FBG sensor.Based on the above research,we design an encapsulation method(stainless steel foil encapsulation)suitable for the strain detection of variable curvature plate structural parts.We set up a cantilever beam experimental system to calibrate the strain sensitivity coefficient of the encapsulated sensor,and verify the strain detection accuracy.The experimental results show that the method can not only improve the sensitivity of the strain detection,but also completely fit with the variable curvature structure to improve the deception accuracy.Secondly,through the study of finite element analysis,the simulation analysis of the deformed structure is carried out with ANSYS,then a simulation method for predicting the deformation of plate and shell structural structures with a certain range of curvature is established.We also built a strain detection system for plate and shell structure based on FBG sensor.The strain results of experimental detection and ANSYS deformation analysis obtained from every measured points are analyzed and compared.According to the above process,the feasibility and accuracy of ANSYS deformation simulation analysis method are evaluated.Then,the relationship between strain and curvature conversion of FBG sensor array is analyzed.The principle of surface reinstruction algorithms based on curvature information are studied.At last,a coordinate conversion method and interpolating scattered data with the B-spline surface reconstruction method are selected.Fiber optic sensing technology and surface reconstruction method are combined.The three-dimensional structure of the deformed plate and shell was reconstructed based on the physical quantities such as the strain measured by the fiber optic sensor network.It provides a comparison object for evaluating the deformation surface obtained by the above ANSYS deformation simulation method.Finally,based on the above findings,the ANSYS method for simulation and prediction of plate and shell structure deformation within a certain range of curvature is established.Then,the error analysis is performed between the above simulation results and the experimental results of the strain detection of the plate and shell structure based on the FBG sensor,and the errors are compensated.It is the best way to build the simulation and monitoring for deformation of plates and shells curative of fitting within a certain range.According to the ANSYS simulation deformation results,seals and filling compensators for the assembly of plate and shell structures are designed,the above mentioned process can ensure the effectiveness of plate and shell structure assembly.In conclusion,this study designs and establishes a deformation simulation and prediction method for assembly deformation of variable curvature shell.This method can be used to accurately design structural compensation components for actual assembly,and the studied method can ensure the effectiveness of aircraft structural component assemble.The method solves the problems of long time consuming,low accuracy of the traditional assembly process of plate and shell structural parts,and relying heavily on the experience of practical experience to estimate the design of seal compensating parts to fill the assembly gap.The studied method can reduce assembly time and improve the quality of assembly.