Method for testing dynamic shearing of composite material

Abstract

The invention discloses a method for testing dynamic shearing of a composite material, and belongs to the technical field of materials. The method comprises the following steps of (1) processing the composite material into a convex-shaped specimen according to the main direction of each material; (2) arranging the specimen on a Hopkinson press rod, dynamically loading, and calculating the anti-shear strength and strain rate of the specimen according to the recorded incidence strain signal, reflection strain signal and transmittance strain signal in the experiment process. The method has the advantages that the additional processing clamp is not needed, and the shearing mechanical property of the composite material in each direction can be measured by the existing Hopkinson press rod, so that the testing cost is reduced, and the influence of the mechanical connection to the measuring accuracy of the Hopkinson press rod can be effectively avoided; in addition, the convex-shaped specimenof the composite material is of a symmetric type, and the bottom part is provided with a connecting area, so as to ensure the occurrence of the shearing damage to the specimen in the loading process.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a composite material dynamic shear test method. Background technique [0002] Composite materials are widely used in the field of aerospace, and aircraft structures have been in service in dynamic environments for a long time. According to research, composite materials have obvious strain rate effects, that is, the strength and stiffness of materials change with the change of strain rate. [0003] Therefore, it is particularly important to study the mechanical properties of composite materials under dynamic loading conditions for the design of aircraft structures, and the dynamic shear mechanical properties of composite materials are an important part of it. [0004] CN203643279U discloses "a measurement device for dynamic shear performance of materials", which loads the test device through the Hopkinson pressure bar, and then performs shear loading on the sample. ...

AI Technical Summary

Problems solved by technology

Due to the contact relationship between the sample and the tooling, and between the tooling and the Hopkinson pressure bar, the stress wave is incident, transmitted and reflected on the contact surface, which eventually leads to a decrease in the accuracy of the test results

CN107063892A discloses "a method for calculating the dynamic shear strength of concrete by using the Hopkinson compression bar". The concrete sample mentioned is cylindrical. Step design is adopted. This method uses asymmetric single-sided shear loading. During the loading process, the sample has composite failure on the shear plane, resulting in large errors in the test results.

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