Research On Experimental Device Test Systems Of Dynamic Mechanical Properties Of Materials

With the rapid development of science and technology, study on dynamicmechanical properties of materials all involve in engineering application of machining,explosive forming, armor penetration and so on. Dynamic mechanical properties ofmaterials significantly different under dynamic load and static loads, it can accuratelymeasure by constructing dynamic mechanics of material experiment and using theexperimental method of dynamic mechanics, but the effect of stress wave, strain rateeffect and measuring element accuracy influence the stability of experimental devicetesting system, therefore, research and development of dynamic mechanicalexperiment platform of high precision, high reliability has important practicalengineering significance.According to dynamic mechanical properties of materials and Johnson-Cookviscoplastic constitutive equations, analysising the effect on the solution of dynamicstress constitutive relation under coupling stress wave effects and strain rate, studyingon the mechanism of two effects of decoupling pressure bar of experimental technique;the mechanical properties mathematical model of material dynamic were establishedby reflection wave and transmission wave strain that based on one-dimensionalassumption, uniform stress assumption and wave equation, to provide theoretical basisfor the construction of dynamic mechanical experiment device.Experimental platform of dynamic mechanical properties of materials weredesigned and constructed that constituting of mechanical system, power system,operating system and measurement system, test systems were set up by speedometer,infrared thermometer, dynamic strain gauge and octagonal ring type dynamometermeasuring element and so on, improving the traditional testing technology of dynamicmechanical experiment device, and measuring of physical parameters of bullet velocity,specimen temperature, stress and strain of the material and specimen impact force in the experiment, to provide hardware support for developing dynamic mechanicalmaterials testing.Finite element model of a high-speed of plane contact and surface contact form ofmetal specimen were constructed base on dynamic mechanics of material experimentplatform and plastic constitutive equations, to analysis the interaction relationshipbetween the forming tools and test process of stress wave propagation, to study on thedynamic mechanical behavior of different impact contact form, to reveals the influencelaw of stress wave effect on the simulation results.40Cr quenched and tempered steel was selected for high speed impact test, tomeasure dynamic stress-strain data of material, and to correct test date and smoothprocessing, to comparative analysis the results of test and simulation, to research thehigh-speed impact process of force, velocity, stress and dynamic mechanical propertiesof multi field coupling wave of dynamic mechanical properties of materials, to discussthe differences between experimental results and simulation results, and to reveal theinfluence mechanism of dynamic mechanical properties by the dispersion effect andtemperature effect.The experimental platform of dynamic mechanical properties of materials weredesigned and constructed base on the one-dimensional stress wave theory, to improvethe test systems, and for the numerical simulation and high-speed impact test, and tocomparative analysis the results of test and simulation, and to research the dynamicmechanical properties of multi field coupling effect of high-speed impact process, andto reveal the influence mechanism of dynamic mechanical properties by the dispersioneffect and temperature effect and to verify the reliability of dynamic mechanicalexperiment.