Multi-scale Simulation Of Drilling Rig Derrick Considering Local Details Features

Drilling rig derrick as an important tool to complete the drilling task,its safety performance of the entire rig system has a very important significance.In the past,the calculation of the drill derrick is based on the linear model of the beam element.This model is too simple to make the analysis result more restrictive and more surfaces,it is difficult to reflect some of the key parts of the node damage,flange contact and other issues.Therefore,this paper builds a multi-scale model to carry on the analysis of its bearing capacity based on the local detail of drilling rig derrick.The main contents and results are as follows:Firstly,the modeling strategy of multi-scale model of drilling rig derive is proposed based on multi-scale finite element theory.The multi-scale model of drilling rig derivation is established by using MPC multi-point constraint method,while the traditional "large-scale" beam element is adopted in the whole derrick,and the "small scale" solid element is used for local detail.And use the MPC contact wizard to solve the interface connection problem,to achieve the effective transmission of force between the cross-scale.At the same time,compared with the traditional model and multi-scale model under the same conditions,which showed the multi-scale method applied in the rig derrick rationality.Taking the ZJ70 DB rig derrick laboratory model as the research object,the multi-scale model experiment was carried out.A full beam model test and a multi-scale model test were carried out,two different test scheme designs and measuring points were arranged by using two different sensing elements.Comparison analysis test results,which proved that the multi-scale model tests can more fully reflect the stress distribution of the local details,and the necessity of the multi-scale model is determined.Based on the rationality and necessity of the multi-scale model of the drilling rig derrick,the "TK" node area,the pin connection structure and the bottom large bearing structure of the rig derrick are selected to have the typical position for multi-scale simulation analysis.And for "TK" local position,the damage analysis is carried out,which prove that the multi-scale model can reflect the local stress gradient of stress concentration.The multi-scale simulation of the drilling rig derrick is used for engineering application,based on the above theory.According to the static load test data of the 7000 m drilling rig derrick,the whole beam model is modified and the benchmark numerical model is established.On this basis,the multi-scale model of the drilling rig derrick is established.According to the design standard of load conditions,the multi-scale analysis of the derrickderrick is carried out for the working conditions and the expected storm.The two directions of the wind direction and the lateral direction are also considered,and the displacement,axial force,bending moment,strength stress and a few parameters to do a comparative analysis.The results show that the multi-scale simulation can reflect the stress distribution of the local bar under the condition load,and realize the popularization and application of the multi-scale simulation method in the load bearing performance of the drilling rig.