The Research On Grinding Temperature Of Carbon Fiber Reinforced Plastics In Ultrasonic Vibration Assisted Grinding

Carbon fiber reinforced plastic(CFRP)is a new type of materials with excellent mechanical performance,which makes it widely used in aerospace,transportation,machinery manufacturing and various industrial fields.However,because of its outstanding anisotropic mechanical properties,high hardness,high strength and other characteristics,conventional processing methods make it difficult to efficiently produce various parts that meet the requirements of use.Therefore,the ultrasonic vibration assisted grinding(UVAG)arises as the processing requirements and the CFRP could be high-quality,high-precision and high-efficiency processed.What’s more,due to the poor thermal conductivity of CFRP,high heat production and without grinding fluid,the heat generated during grinding can be easily accumulated in the processing area of the workpiece and impact the surface quality seriously.Therefore,it is a meaningful work to study the distribution of temperature field of the workpiece during UVAG of CFRP and explore ways to reduce the grinding temperature.In order to solve the above problems,the fiber Bragg grating(FBG)sensors were selected as the monitoring tool for the grinding temperature.An embedded multi-gradient annular temperature measurement method was designed to cover the grinding area of the workpiece for real-time monitoring.Then the finite element simulation and UVAG experiments were carried out for various processing parameters(grinding parameters,material parameters,tool parameters,amplitude of ultrasonic vibration)which would affect the grinding temperature.Finally,the simulation and experimental results were compared and analyzed,and various processing parameters were fed back and optimized to obtain the setting methods of various processing parameters for reducing the grinding temperature.The main research contents of this thesis are as follows:(1)According to the structural characteristics of CFRP and processing characteristics of UVAG,the propagation mechanism of grinding temperature was studied.What’s more,the model of grinding temperature suitable for this thesis was established and the related processing parameters which influence grinding temperature were analyzed.(2)A grinding model was established for finite element simulation to verify the correctness of the grinding temperature propagation model and study the influence of various machining parameters on the grinding temperature based on the grinding temperature propagation model of UVAG of CFRP.(3)The grinding experimental platform of UVAG of CFRP was set up and the embedded temperature measurement system based on FBG sensors was designed to carry out the grinding experiments for temperature monitoring.Firstly,the problems of cross-sensitivity of FBG sensors were researched and solved to improve the accuracy of temperature measurement system;besides,a series of single-factor experiments affecting the temperature of grinding were set up to study various processing parameters on the grinding temperature;finally,the simulation and experimental data were comparative analyzed and the ideal setting method of processing parameters were obtained to reduce the grinding temperature during processing and improve the surface quality of the workpiece after processing.