Method for inverting elastic constant of composite material with anisotropic characteristics

Abstract

The invention discloses a method for inverting an elastic constant of a composite material with anisotropic characteristics, which comprises the following steps of: 1, solving frequency dispersion equations of a symmetric mode and an antisymmetric mode in an orthotropic plate by adopting a numerical method, and listing frequency dispersion curves of corresponding modes; 2, the excitation frequency of the ultrasonic guided wave test is selected by analyzing the influence of the elastic constant on the frequency dispersion curve; establishing a corresponding relation graph between the elastic constant and the guided wave propagation speed; 3, measuring the propagation speeds of the symmetric mode and the antisymmetric mode in the composite material structure by using an ultrasonic guided wave detection method; and 4, performing inversion by using the relation graph of the elastic constants and the guided wave propagation velocity to obtain the corresponding elastic constants. The method has the technical effects that the anisotropic composite material can be subjected to nondestructive testing, and the elastic modulus and the shear modulus of the composite material component in each main shaft direction can be accurately and quickly obtained.

Description

technical field [0001] The invention belongs to the field of mechanical performance testing of composite materials, and in particular relates to a method for determining the elastic constant of composite materials by means of ultrasonic guided wave detection. Background technique [0002] Composite materials have high specific strength, high specific modulus, corrosion resistance, fatigue resistance and other excellent properties, and have been widely used in aerospace, automobiles, ships and daily life. In the field of aerospace, the size of composite material components is large, and there is a specific need for testing methods related to elastic modulus for such large components. Existing ultrasonic testing methods use body waves or surface waves for measurement, but for composite materials, their elastic properties are anisotropic, and it is impossible to obtain reliable results in each axis direction on large components by body wave methods. [0003] The measurement of...

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Problems solved by technology

[0005] The invention of this method obtains the elastic modulus of the material to be tested by solving the theoretical dispersion curve of the guided wave and comparing and analyzing it with the measured dispersion curve, but the measurement and calculation process of the method is complicated, and the method is based on isotropic materials (such as: The guided wave theory in homogeneous materials such as metals and resins) can measure the elastic modulus and Poisson’s ratio, but for materials and structures with anisotropic characteristics (at least 5 independent elastic constants) such as composite materials not applicable

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