Stress-Strain Relationship of Steel Bars at Super-low Temperature

Abstract:

Mechanical properties of three kinds of 84 steel bars (HRB335, HRB400, and HRBF400) were studied through tests under low temperature ranging from -180℃ to -80℃.Tensile specimens were prepared according to national code of GB/T 3239—2006.Through tensile tests,the mechanical behaviors of these rebars under low temperature were studied.Analysis of the test results reveals that the shape of the stress-strain curve and the ultimate strain for steel bars may not be changed by the temperature，but the yield plateau,the yield strength,the ultimate strength,and the hardening strain of steel bars will increase with the decrease of the temperature.Based on the test results,regression equations of the characteristic values reflecting mechanical properties of rebars in super-low temperature environment were established,and then the stress-strain relationship of steel bars at super-low temperature was proposed.

Key words:super-low temperature; rebar; stress-strain relationship; mechanical characteristic value