An experimental study of the disc-jaw relative displacement along the contact length in a standardized Brazilian disc test using 3D DIC

Introduction: A recently introduced theory [1] for the determination of frictional stresses developed at the disc-jaw interface during the standardized execution of the Brazilian disc test is here assessed experimentally using the 3D Digital Image Correlation technique. According to this theory the frictional stresses T(τ), at any point τ of the common contact length, are related to the mismatch U(τ) between the disc’s and jaw’s tangential displacements as Τ(τ)=fU(τ)P(τ). Here f is a constant related to the coefficient of friction and P(τ) is the distribution of radial pressure at point τ [2]. A typical variation of T(τ) along the contact arc is shown in Fig.1 for various f-values.