Research On Drilling Force And Surface Defect Of Carbon Fiber Composites Under Low Frequency Vibration Drilling

Carbon fiber composite materials are widely used in aircraft industry,automobile manufacturing,equipment manufacturing,sporting goods and other fields due to their excellent physical and mechanical properties.The use of carbon fiber composite materials to make structural parts usually requires the processing of connecting holes to meet the assembly requirements.However,as a difficult-to-machine material with a special structure,defects and quality problems are easily generated during processing,which affects the use of parts.In this paper,it is of great theoretical significance and application value to study the low-frequency vibration drilling force and surface defects of carbon fiber composite materials.Starting from the cutting mechanism of carbon fiber composite materials,the paper analyzes the relationship between the cutting form,chip formation method and surface quality in different fiber directions,and obtains the change rule of the cutting thickness durin g the low-frequency vibration drilling process,successfully explaining the low-frequency vibration The reason for the formation of drilling force during drilling is based on this,and a critical axial force model of twist is established.The stress-strain relationship and damage model based on the Hashin failure criterion of carbon fiber composite materials were established.Through ABAQUS simulation analysis,the Mises stress variation characteristics of carbon fiber composite laminates in different stages during drilling were obtained.Through simulation of the drilling process and tests The results of comparative analysis show that the error between the maximum axial force and the average axial force is within 15%,which verifies the effectiveness of the simulation model.Taking unidirectional and woven carbon fiber composite laminates as the object,using single-factor and multi-factor orthogonal test methods,the effects of amplitude,feed rate and cutting speed on drilling axial force and torque were studied,and the shaft was established.The empirical regression model of directional force and torque shows that the instantaneous axial force of carbon fiber composite materials when drilling at low frequency is greater than that of traditional drilling methods,but the average axial force is much smaller than that of conventional drilling.A method for calculating the orifice delamination defect area based on image processing is proposed.By calculating the delamination factor,a delamination factor prediction model is established,and the effect of amplitude on the hole circularity and hole wall roughness is obtained.It shows that it is an effective method to solve the hole processing of carbon fiber composite materials during low frequency vibration drilling.