One-dimensional lamination crack tension test method based on Hopkinson principle

Abstract

The invention discloses an one-dimensional lamination crack drawing test method based on the Hopkinson principle, Advantages: because the incident rod and the rod shaped test piece completely or approximately satisfies the impedance match condition, the one-dimensional lamination crack drawing test of large size test piece can be performed based on the Hopkinson compressed rod; in the polyphase brittle material (such as concrete) impact characteristic experiment research field, the method can be applied for the dynamic experiment and research to the concrete containing large sized aggregate accordance with engineering reality, in order to cause the test result to have macroscopic validity; and the length of the rod shape test piece satisfies the condition: Ls=2L(impact rod)C(impact rod)Cs, the lamination drawing crack approximately occurs in the middle of the test piece, thereby, the stress adequation on the section of the test piece is ensured.

Description

technical field [0001] The invention relates to a test method for mechanical properties of materials, in particular to a one-dimensional spalling tensile test method based on Hopkinson's principle. Background technique [0002] The research on the dynamic constitutive characteristics of heterogeneous, multiphase brittle materials (such as concrete, rock and engineering ceramic composites, etc.) Discipline frontier research hotspots. Represented by the most widely used concrete in the engineering field, in its working process, in addition to bearing static loads, it also bears dynamic loads, such as the effects of earthquakes, wind loads and explosions on buildings, and the impact of waves on coasts and seas. The impact of the oil production platform, the impact of the barge on the wharf, the impact of the vehicle on the road facilities, etc., will cause the concrete to deform at a strain rate that is many orders of magnitude higher than the static state, and show different ...

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Problems solved by technology

[0003] As we all know, the experimental research on the impact characteristics of multiphase brittle materials such as concrete, whether abroad or at home, is the first choice to use the Hopkinson compression bar test technology. However, concrete is a heterogeneous material containing aggregates of different sizes in the microscopic view. When studying its macroscopic constitutive properties, the size of the specimen is required to be at least an order of magnitude larger than the size of the aggregate to ensure the validity of the test results in the macro sense. In recent years, although many researchers have used the stress in the long specimen The spalling tensile fracture or disc splitting test method caused by wave reflection is used to study the dynamic tensile strength of concrete experimentally, but limited by the size of the Hopkinson compression bar, it is limited to the case where the aggregate size is ≤12mm. The large concrete containing large-sized aggregates that conforms to the engineering reality cannot be used for corresponding dynamic experimental research, so the validity of the experimental results in the macroscopic sense cannot be guaranteed.

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