A Simple and Effective Method for Determining the Shear Moduli of Structural Materials

Determining interlayer shear modulus of composite materials by the method of three-point transverse bending is considered, and Timoshenko approaches to estimating the shear strains in this type of loading are assessed. It is shown that these approaches make it possible to determine the shear component of beam deflection with an accuracy acceptable for practice in testing them in three-point transverse bending, but only for isotropic materials. For anisotropic materials, they are unacceptable. These approaches are also unacceptable for determining the shear modulus of isotropic and anisotropic materials. Based on the data obtained as a result of the study, a simple and economical method for determining the shear moduli in the three-point transverse bending is proposed. This method was tested on both isotropic and composite materials with different reinforcement structures. Results showed a good agreement between the calculated and experimental values of the shear moduli for all the materials considered, which confirmed that the method proposed method can be used in practice.