Study On Design Of Large Deformation Extensometer For Tensile Tester

With the increase in the kind of engineering materials,expansion of application fields,the importance of the study of the mechanical properties of the material has become increasingly prominent.Extensometer is an indispensable tool in stress and strain testing,while the mechanical and electronic extensions have a small range of measurement.At the same time,traditional photoelectric encoder extensometers can easily cause signal acquisition errors,which results in large-scale extensometers that do not conform to countries.Verification procedure requirements.In order to more accurately and quickly measure the performance parameters of non-metallic materials,this paper studies and designs a non-contact magnetic grid large deformation extensometer.The paper takes the physical product of Xinguang Testing Machine Co.,Ltd.as the research object firstly,and establishes the mechanical structure of the large deformation extensometer.Through theoretical calculations and finite element analysis of the drive elements,the 2T gate type electronic universal testing machine was identified as the supporting equipment;the actual surveying and mapping test space was calculated and the four components of the sample holder,transmission system,counterweight device and fixing device were calculated.Structure size;Using SolidWorks interference detection and appearance rendering function,get a large-scale extensometer mechanical structure with accurate size and reasonable structure.Extensometer for large deformation finite element analysis and motion simulation.Using Simulation's section trimming and detection functions,static analysis was performed on key components such as gauge clamps to optimize the parts structure.Through the linear buckling analysis of ANSYS workbench,a complete machine model that meets the work strength requirements was obtained;using SolidWorks Motion The module generates a clear demo video.Research and design of signal acquisition systems and interface devices.According to the characteristics of various types of signal acquisition systems,a non-contact magnetic scale acquisition system was determined.The selection of the system determines the components of the acquisition system;the acquisition system components are matched to the host of the extensometer,and the final large-extensometer extensometer is determined.The whole structure;through the signal shaping of the components,frequency multiplication,direction identification,digital-analog conversion processing,developed a stable and reliable interface device.Set up an experimental platform and perform extensometer test and analysis.Using the dial indicator tool,the displacement calibration of the mainframe,holder and extensometer of the testing machine was completed,and the commissioning process was standardized;the tensile test of the vulcanized rubber and hard plastic materials was consistent with the standard value of the dial indicator.The results of the data and the generation of the experimental report data table verify that the prototype can meet the requirements of the material experiment with a large elongation rate,and more effectively illustrate the feasibility of the large-extensometer extensometer prototype.