The Design And Research Of Fatigue Tester For The Mast Of Rotary Drilling Rig

Fatigue tester is an important equipment of contemporary engineering simulations,which is possible to reflect the real performance of the product at lower cost and providesa reliable basis for the design and improvement of products.With the rise of domesticRotary Drilling Rig and the increasingly fierce market competition, the reliability of theproduct also get the more and more attention of the domestic manufacturers and customers.Under this background, this paper designed a fatigue test system for the rotary drilling rigmast, whose function is to simulate the actual load conditions of the mast under laboratoryconditions.The purpose is to find the dangerous parts of the mast stress to improvestructural design and reduce mast cracking or open welding faults.Therefore, this researchhas important application and its economic value.To mast fatigue tester machine as the research object, this paper completed thefollowing work:Firstly, after researching and analysing on the mast under different conditions ofloading conditions and according to the technical requirements,the final design scheme isdetermined.And key mechanical structure of testing machine is designed and analysed toensure the safety of the test machine and convenience of specimen installation operation.Secondly, according to the functional requirements of the test machine,this machineis designed to include hydraulic system schematic diagram,completed the selectioncalculation of hydraulic components and accessories.720kN servo actuator is alsodesigned and checked.Thirdly, in order to meet control accuracy requirement under different test inputsignals,mathematical model of the testing machine hydraulic system is established. Bycomparing dynamic control simulation results under two control strategies and differenttest signals, the control strategy based on PIDF is determined finally.And to meet theperformance of the entire control system coordination load requirements, differentcompensators were designed.Finally, aiming at the overall functional requirements of the fatigue tester, a new type of three-level distributed servo control systems is designed. And the main hardware andsoftware design are described. Eventually,the debugging experiment furtherly shows thefeasibility of the control strategy based on PIDF and the accuracy of the simulation model.