Torque Measurement Technology For The Drill Based On Fiber Bragg Grating Sensor

Torque is one of the important mechanical parameters in the process of drilling work.It is important to ensure the safe operation of the entire system by using appropriatesensors and measurement methods for the real-time monitoring of torque of the drillingsystem. In practical engineering, the forces of the drill pipe are very complex, which issubject to composite loads of the Moment, torque and axial force. How to separate thevarious mechanical parameters in the composite load has become the key technologyof torque detection.In this thesis, a new method that separates pressure, moment and torque on externalspiral drill which could get approximate analytic solution was presented based on theANSYS finite element simulation in theory. The torque of the drill during drilling workwas measured in the experimental by FBG sensors, which verify the feasibility of thismethod. The main contents include the following aspects:1. This thesis analyzed synthetically and compared the advantages anddisadvantages of different methods about torque measurement, described thecharacteristics and application status of FBG sensor, and analyzed theoretically how touse the FBG sensors for the torque measurement.2. The tangential force conductions of the cylindrical rod, different thread profiles ofsingle thread and double thread under the same torque were analyzed comparatively,which provided theoretical basis for selecting monitoring points.3. Based on the theoretical analysis of cylindrical rod with pressure, moment andtorque. The diameter and the material of the threaded drill and cylindrical rod were thesame. Approximate analytical solution of pressure, moment and torque are achievedunder the same loads through fitting and correcting. The maximum difference value ofpressure, moments and torques obtained using this correction method compared withthe loading value were0.47%,1.70%,0.60%separately. The influence of thread drillpipe structure, size and applied pressure to the correction factor of pressure, momentand torque were also analyzed.4. Measuring system of bending twist were designed and built, the pure torque andsimple bending and torsion torque and hollow cylindrical drill with it had beenmeasured, and the error was between0.70%and6.91%. In the process of onlinedetecting mechanical parameters when drilling, the separation of pressure, moment, and torque were achieved. The curves changing with time of the three parameters weregiven and the errors of the measured results were analyzed.This thesis provided a theoretical basis for torque measurements of threaded drilland verifies the feasibility of pressure, moment and torque online separation anddetection method based on fiber Bragg Grating.