Method for determining tensile elasticity modulus of fragile material in SHPB (split Hopkinson pressure bar) split tension test

Abstract

The invention discloses a method for determining the tensile elasticity modulus of a fragile material in an SHPB (split Hopkinson pressure bar) split tension test, which comprises the following steps: placing a cylindrical sample on an SHPB split tension test machine; exerting an impact load on the sample along the radial direction of the sample; measuring the displacement of the sample in a stress-loading process; and calculating the dynamic tensile elasticity modulus Edt of the material by utilizing the formula disclosed in the specification, wherein P(t)max is the maximum value of the dynamic load, L is the length of the sample, D is the diameter of the sample, mu is the Poisson ratio of the sample material, and Delta ut is the damage displacement of the central diameter length of the sample along the vertical loading direction when the sample is damaged. The method for determining the tensile elasticity modulus of a fragile material in an SHPB split tension test can be easily implemented and can acquire accurate measurement result.

Description

technical field The invention relates to a method for measuring the tensile elastic modulus of brittle materials in the SHPB splitting tensile test. technical background The tensile modulus of brittle materials is an important test parameter. At present, it has been used to determine the static or quasi-static (10 -1 ~10 1 MPa / s) method for tensile modulus of brittle materials. At medium to high load rates (10 5 ~10 6 MPa / s), the SHPB (Split Hopkinson Pressure Bar, Hopkinson pressure bar, referred to as SHPB) device can be used to perform impact splitting test on the sample, and the dynamic splitting strength can be calculated. But for that load rate (10 5 ~10 6 MPa / s) dynamic tensile modulus, due to the limitation of current testing methods, there is no relatively standardized method at present. In order to determine the tensile modulus of the sample in the SHPB splitting test, many researchers use the method of sticking the strain gauge at the center of the disc c...