The Structural Strength And Reliability Analysis Of K Type Derrick And Substructure

K type derrick is the most widely-used type of rig derrick,so its structural strength and reliability directly affect the safety of the entire rig system.In order to solve the problem of stress concentration and low reliability under K type derrick and matched substructure,the dissertation mainly uses the stochastic finite element method to analyze the strength and reliability of K type derrick and substructure.Based on a large number of domestic and overseas literatures and field researches,the stochastic finite element method is put forward,and the finite element method and extended finite element method are used as contrast and supplement.The study focuses on JJ170/41-K,JJ250/45-K,JJ225/45-K,JJ315/45-K,JJ450/45-K5 derrick,5000m slide type substructure,5000m marching type substructure,7000m slide type substructure and 7000m marching type substructure.The main research results include the reliability calculation model of derrick and substructure,a large number of finite element databases,the reliability evaluation software of K type derrick and matched substructure on the database,the application of the software for a variety of condition analysis,modified derrick and substructure operating manual.On the basis of the research results,the following main conclusions and suggestions are extracted:(1)Based on the reliability theory of distribution parameter estimation,Monte Carlo simulation and stress-intensity distribution interference,this dissertation proposes a stochastic finite element method as the basic process and method of strength analysis and reliability evaluation of K-type derrick and matched substructure,which can effectively analyze and evaluate derrick and substructure reliability on a variety of models and conditions(2)The simulation results show that the stress distribution and displacement distribution of the derrick and substructure on a variety of conditions,such as hook load,derrick raising,derrick tilting,and the main stress concentration is analyzed emphatically.(3)The statistical results of the simulation database are analyzed,then a series of characteristic parameter of random variable and the reliability of the derrick and substructure are obtained.The curve of distribution function is drawn.The correlation coefficient between all the input parameters and the output parameters is obtained by using the correlation coefficient formula,and the sensitivity analysis is carried out.(4)The reliability evaluation software of K type derrick and substructure uses APDL language for parametric modeling,and it is very convenient to modify the model.Software uses powerful database function of VB language and visual design platform,which greatly reduces the threshold of use.It can also improve the scalability of the software.(5)Based on the the developed software,the derrick operation manual and substructure operation manual used in the field are modified and perfected,and the corresponding scoring mechanism is established.The corresponding index items of reliability evaluation are also added.