SHPB (Split Hopkinson Pressure Bar) experimental method for concrete material

Abstract

The invention discloses an SHPB (Split Hopkinson Pressure Bar) experimental method for a concrete material. The experimental method is used for testing a Poisson's ratio of a concrete sample and reducing the error of a concrete SHPB experiment. The method comprises the following steps: preparing a cylindrical concrete sample of an SHPB experiment; pretreating the concrete sample, symmetrically attaching two 45-degree strain rosettes on side walls of the pretreated concrete sample, wherein the 45-degree strain rosettes are connected with an oscilloscope through a strain gage; fixing the concrete sample between an incident bar and a transmission bar through a clamp and a protective cover, and connecting the strain gauge with the oscilloscope through a strain gage; finally, shooting shots, and carrying out the SHPB experiment. According to the method disclosed by the invention, the Poisson's ratio of the concrete sample can be measured by adopting the 45-degree strain rosettes attached to the concrete sample, and compared with the past Poisson's ratio measurement method, the method disclosed by the invention is simple and easy to operate; due to pretreatment of the concrete sample, the error in the experimental process can be reduced, and the experimental accuracy is improved.

Description

technical field [0001] The invention belongs to the field of material characteristic testing, and in particular relates to a SHPB experimental method for concrete materials. Background technique [0002] The separated Hopkinson compression bar is one of the main experimental devices for measuring the dynamic mechanical properties (stress-strain curve) of materials. It uses strain gauges attached to the incident bar and the transmitting bar to measure the loading waveform, and uses the one-dimensional wave theory The one-dimensional strain assumption and the internal stress or strain homogenization assumption of the specimen calculate the dynamic stress-strain relationship of the specimen sandwiched between the two rods, avoiding the difficulty of directly measuring the stress-strain of the specimen under impact. Since it was proposed, it has obtained Wide range of applications. [0003] To obtain accurate dynamic stress-strain curves of experimental materials, the above two...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a kind of SHPB experiment method that is used for concrete material, has solved the problem of lateral inertia effect because of the excessive roughness of concrete specimen end face in SHPB experiment; And the small failure strain of the concrete material causes the uneven internal stress of the concrete specimen

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