Detection Method For Parameters Of Tubing And Casing Thread Premium Connection Based On Reverse Engineering With CMM

In order to obtain the precise geometrical parameters of tubing and casing thread premium connection,the precise three-dimensional model of the tubing and casing joint can be established according to the physical product,and then the computer finite element mechanical simulation calculation in the joint strength failure analysis,or the optimization design of the product can be carried out in the reverse engineering.The detection method for parameters of tubing and casing thread premium connection was studied.In this paper,the measurement space coordinate system is established by analyzing the structure of the tubing and casing joint,the route and number of measurement points are planned according to the thread structure,and the data of the measurement points on the thread surface is obtained by using a coordinate measuring machine.Drawing on the idea of "from point to line" in reverse engineering,using the data points of a measuring point route,combined with the distance algorithm between straight lines,straight line fitting algorithm and straight line equation algorithm to establish the detection method of each thread parameter,and using MATLAB software realizes the computer programming of intersection point calculation and straight line fitting calculation,thus obtaining a detection method for parameters of tubing and casing thread premium connection.Taking a premium connection joint of a tubing and casing as an example,the thread parameter detection test was carried out.The detection value and the actual value of the method in this paper were compared.The results confirmed that the method in this paper has small error,high precision,convenient detection process Practicality.Combined with the data points and reverse engineering technology of all the measuring points,the reverse modeling of the thread was carried out by UG software.The parameters of the three-dimensional model were tested,and the results confirmed that the model had high accuracy,and at the same time confirmed that the route planning and number of measuring points in this paper were designed reasonably and suitable for partial trapezoidal threads.The detection method in this paper can obtain the specific values of the thread parameters,and then can be based on the actual situation of three-dimensional modeling and optimal design of the thread,thereby enhancing the connection strength and applicability of tubing andcasing connection.At the same time,it can absorb advanced technology and improve the existing thread structure,which has certain theoretical significance for improving the performance of the tubing and casing connection.