Study On Dynamic Mechanical Properties Of 304 Austenitic Stainless Steel Considering The Effect Of High Temperature

304 austenitic stainless steel presents good mechanical property,beautiful structure and easy maintenance,which is widely used in industrial and building structures.In addition to the single working condition such as dynamic load and high temperature,it is inevitable that buildings will suffer the coupling effects of multiple disasters during their service life,such as impact,explosion and high temperature.Under the coupling loads,structures will show obviously different mechanical properties,in which the dynamic constitutive relationship of materials is essential to analyze the dynamic response of building structures.At present,the investigations on 304 austenitic stainless steel mainly focuses on the single static,dynamic and high-temperature,and the dynamic mechanical properties of 304 austenitic stainless steel under different temperature and strain rate coupling have been found,The corresponding dynamic constitutive model is established.The main research contents are as follows:（1）The quasi-static compression test under the temperature of 20℃～600℃ was completed by electronic universal material testing machine,and the basic mechanical properties were obtained.The results show that the yield strength of the material decreases significantly with the increase of temperature.（2）The dynamic compression tests of 304 stainless steel under the action of temperature 20℃～600℃ and strain rate 1000s^-1～3000s^-1 were carried out by using a high temperature Hopkinson pressure bar with synchronous assembly heating system.The stress-strain curves of 304 stainless steel under different strain rates and temperatures were obtained,and the effects of strain rate and temperature on the dynamic mechanical properties of 304 stainless steel were given.（3）Based on the experimental data,Johnson cook model was used to fit the dynamic constitutive model of 304 stainless steel,and the relevant parameters of Johnson cook model were determined.The results show that the stress-strain curve fitted by J-C model is in good agreement with the experimental results,which indicates that the J-C model used in this paper can effectively describe the plastic flow characteristics of 304 stainless steel under the action of temperature from 20℃ to 600℃ and strain rate from 0.001s^-1 to 3000s^-1,which can provide reference for the dynamic analysis of building stainless steel under high temperature and high strain rate.