Research On Load Monitoring Of Composite Elastic Components Based On Self-Sensitive Properties

Carbon fiber composites are used in a wider range of applications,and the high plasticity of carbon fiber composites makes them suitable for use in more complex environmental scenarios.Carbon fiber composite springs have higher specific strength,specific modulus and other mechanical properties than traditional metal springs,and carbon fiber materials themselves have resistance-resistance characteristics to deformation,and scholars for non-destructive testing of composite materials under regular shapes are becoming more and more There are many researches on non-destructive testing of composite materials compared with irregular or complex structures.Therefore,it is necessary to study the application of carbon fiber composite springs in the field of load monitoring while carrying loads.In this paper,the composite spring made of carbon fiber prepreg is studied under the quasi-static compression.Through the combination of finite element analysis,numerical calculation and experiment,the feasibility of carbon fiber composite spring in the field of load monitoring is studied and the related factors of resistance change are analyzed.The relevant research steps consist of the following parts.(1)Quasi-static compression test.The research on the load monitoring of carbon fiber composite springs is based on the quasi-static compression of carbon fiber composite springs.First,consider the manufacturing process of composite springs,design related molds,and select suitable materials to complete the fabrication of composite springs.Secondly,the prepared carbon fiber composite spring was subjected to quasi-static compression test.The resistance change of the carbon fiber composite spring was measured in real time by the four-end test method during the compression process,and recorded and stored.To verify the effect of compression rate on resistance changes,quasi-static compression is performed at different rates.(2)Coefficient determination test.In order to measure the influence coefficient of strain on the change of the resistance of the carbon fiber composite spring.Carbon fiber composite slats were fabricated,and tensile tests were performed on composite slats.In the stretching process,high-speed camera digital image processing technology(DIC)was used for auxiliary measurement of strain,and acoustic emission(AE)was used to monitor composite in real time.The damage condition of the material slab during the stretching process is brought into the simulation numerical analysis by the coefficient measured by the experiment,and the relationship of the simulated resistance change is obtained.(3)Finite element simulation and numerical calculation analysis.Secondary development of Abaqus,creating a graphical user interface to facilitate solid modeling and meshing of springs with different specifications.On the premise of quasi-static compression simulation of composite springs,the thermo-electric coupling module and numerical calculation in Abaqus are used to analyze the resistance change factors of carbon fiber composite springs during quasi-static compression,and the strain pairs are obtained by experimental and numerical calculations.The resistivity change influence coefficient is corrected for the measured strain-resistance coefficient.