Compressive mechanical properties of 10^# lowcarbon steel with normalizing heat treatment are studied. A Gleeble system is adopted to analyze the quasi-static properties and thermal softening effects of heat treated 1...Compressive mechanical properties of 10^# lowcarbon steel with normalizing heat treatment are studied. A Gleeble system is adopted to analyze the quasi-static properties and thermal softening effects of heat treated 10^# steel,while a Hopkinson bar apparatus is used to investigate its dynamic characteristics under different strain rates. The results showthat yield stress of heat treated 10^# steel is more than that of untreated one at room temperature. When the specimens are tested at different temperatures,yield stresses decrease with increasing temperature except 573 K. Moreover,the influence of strain rate on yield stress are verified,which shows that the yield stress increases sharply from 500 s^-1 to 1 890 s^-1,while it changes a little from 1 890 s^-1 to 4 850 s^-1. The results indicate that yield stress is mainly influenced by hardening effect at lowstrain rate and controlled by both thermal softening effect and strain rate hardening effect at high strain rate.展开更多
Impact compression experiments for the steel fiber-reinforced high-strength concrete(SFRHSC)at medium strain rate were conducted using the split Hopkinson press bar(SHPB)testing method.The volume fractions of steel fi...Impact compression experiments for the steel fiber-reinforced high-strength concrete(SFRHSC)at medium strain rate were conducted using the split Hopkinson press bar(SHPB)testing method.The volume fractions of steel fibers of SFRHSC were between 0 and 3%.The experimental results showed that,when the strain rate increased from threshold value to 90 s^(-1),the maximum stress of SFRHSC increased about 30%,the elastic modulus of SFRHSC increased about 50%,and the increase in the peak strain of SFRHSC was 2-3 times of that in the matrix specimen.The strength and toughness of the matrix were improved remarkably because of the superposition effect of the aggregate high-strength matrix and steel fiber high-strength matrix.As a result,under impact loading,cracks developed in the SFRHSC specimen,but the overall shape of the specimen remained virtually unchanged.However,under similar impact loading,the matrix specimens were almost broken into small pieces.展开更多
基金Supported by the Key Laboratory of Forensic Marks,Ministry of Public Security(2014FM KFKT03)
文摘Compressive mechanical properties of 10^# lowcarbon steel with normalizing heat treatment are studied. A Gleeble system is adopted to analyze the quasi-static properties and thermal softening effects of heat treated 10^# steel,while a Hopkinson bar apparatus is used to investigate its dynamic characteristics under different strain rates. The results showthat yield stress of heat treated 10^# steel is more than that of untreated one at room temperature. When the specimens are tested at different temperatures,yield stresses decrease with increasing temperature except 573 K. Moreover,the influence of strain rate on yield stress are verified,which shows that the yield stress increases sharply from 500 s^-1 to 1 890 s^-1,while it changes a little from 1 890 s^-1 to 4 850 s^-1. The results indicate that yield stress is mainly influenced by hardening effect at lowstrain rate and controlled by both thermal softening effect and strain rate hardening effect at high strain rate.
基金The authors would like to gratefully acknowledge the National Natural Science Foundation of China(Grant No.50708022)the Natural Science Foundation of Guangdong Province(No.06301038).
文摘Impact compression experiments for the steel fiber-reinforced high-strength concrete(SFRHSC)at medium strain rate were conducted using the split Hopkinson press bar(SHPB)testing method.The volume fractions of steel fibers of SFRHSC were between 0 and 3%.The experimental results showed that,when the strain rate increased from threshold value to 90 s^(-1),the maximum stress of SFRHSC increased about 30%,the elastic modulus of SFRHSC increased about 50%,and the increase in the peak strain of SFRHSC was 2-3 times of that in the matrix specimen.The strength and toughness of the matrix were improved remarkably because of the superposition effect of the aggregate high-strength matrix and steel fiber high-strength matrix.As a result,under impact loading,cracks developed in the SFRHSC specimen,but the overall shape of the specimen remained virtually unchanged.However,under similar impact loading,the matrix specimens were almost broken into small pieces.
