Research On The State Of Mechanical Interface Based On Laser Ultrasonic Technology

The mechanical interface is widely found in high-end equipment such as aerospace vehicles,high-precision machine tools,shield machines,and deep submersibles.Due to the characteristics of convenient installation and high bearing capacity,it is often used in key parts of the system and plays a very important role in ensuring the safe and efficient operation of parts.With the increasing precision and reliability requirements of high-end equipment,the detection of the contact state of the mechanical joint surface is particularly important.The contact state of the mechanical joint surface has a great influence on the normal operation of the parts,but there is currently very little research on the contact state of the mechanical joint surface.As an emerging detection technology,laser ultrasound has the characteristics of non-contact,long distance and high space-time resolution,etc.,has a very wide reference value in industrial detection.As a kind of laser ultrasonic wave,the laser ultrasonic guided wave has the characteristics of long propagation distance and sensitivity to micro-structural damage,and is especially suitable for research on the contact state of the mechanical joint surface.In order to develop the excitation ultrasonic detection method,this article selects the two most common mechanical joint surfaces of interference fit and bolt connection for research.Aiming at the research on the contact state of the mechanical joint surface of the interference fit,firstly,the research route is designed,the detection method of the laser ultrasonic detection of the contact state of the mechanical joint surface of the interference fit is proposed;secondly the sample is designed and prepared for experimental exploration,the experimental exploration is conducted and the experimental data is subjected to amplitude analysis and power spectral density(PSD)analysis;finally,based on the power spectral density(PSD)analysis results,the power spectral density is integrated at the corresponding frequency to construct the relationship between the guided wave power and the interference,combining with the theory of micro-convex contact of rough joint surface,the experimental results are analyzed.Aiming at the research of the contact state of the mechanical joint surface of the bolt connection,the research route is firstly designed,the detection method of the laser ultrasonic detection of the contact state of the mechanical joint surface of the bolt connection is proposed,and the sample is designed and prepared;secondly,a research on the relationship between the bolt clamping force and torque is carried out,a calibration experiment on the conversion coefficient K of the bolt torque and bolt clamping force is performed,and the value of the conversion coefficient K in the experiment is obtained;then,the contact state detection experiment of the mechanical joint surface of the bolt connection is performed,and the amplitude analysis and power spectral density(PSD)analysis of the experimental data are performed;finally,based on the analysis result of the power spectral density(PSD),the power spectral density is integrated at the corresponding frequency,the relationship between the guided wave power and the bolt clamping force is constructed,combining with the theory of micro-convex contact of rough joint surface,the experimental results are analyzed.In order to achieve the purpose of rapid analysis of experimental data,a set of software based on laser ultrasound technology suitable for the study of the contact state of the mechanical joint surface is developed.