Study On Mechanical Properties And Selection Methods Of ?3.5x8.75mm Standard Copper Columns

Copper cylinders play an important role in the chamber pressure testing of arms due to its characteristics of easy operation,stable result and low cost.But our existing pressure-measuring copper cylinder series had problems of narrow coverage,various equipment specification and backward calibration specifications.3.5x8.75mm quasi-dynamic calibrating copper cylinder system built to solve these problems was not yet mature,the design of plastic pressure-measuring elements needs to be optimized and there is no standard in grading method of quasi-dynamic calibrating copper cylinder.Based on the present situation,the mechanical properties of ?3.5x8.75mm copper cylinder pressure measurement system and the grading method of standard pressure-measuring copper cylinder was studied in this paper.By analyzing the basic principle of copper cylinder pressure measurement,the mechanical properties of ?3.5x8.75mm cylindrical and conical copper cylinders were studied with the help of numerical simulation and static calibration experiment.The optimal design scheme of copper cylinders was also put forward.Simulation was used to research and optimize the tolerance clearance between the piston and cylinder liner in current crusher gauge,and experiment was carried out to verify the feasibility of optimal design.The mathematical model of copper cylinder pressure measurement was established by theoretical analysis.The dynamic constitutive relation of the copper cylinder was studied experimentally.Based on the analysis,the deformation law of the column was simulated and analyzed,and the reliability of the mathematical model was verified by comparing the quasi-dynamic calibration experimental data and simulation results.According to the method of using standard copper cylinder,the factors influencing the measuring uncertainty of standard copper cylinders were analyzed,the model of uncertainty evaluation is given and the uncertainty control method of standard copper column uncertainty is studied.Combining the characteristics of quasi-dynamic calibration and grading selection of copper cylinders in existing static calibration system,the grading method and the criterion of quasi-dynamic calibrating standard copper cylinders are studied.Study on the grading method of mechanical properties for the standard copper in this paper had certain reference value for perfecting the ?3.5x8.75mm copper cylinder system.