Question

Chapter 16, Problem 16.17 Compute the longitudinal tensile strength of an aligned glass fiber-epoxy matrix composite in which the average fiber diameter and length are 0.0135 mm (0.53 x 10-4 in.) and 1.58 mm (0.062 in.), respectively, and the volume fraction of fibers is 0.33. Assume that (1) the fiber-matrix bond strength is 100 MPa (14,500 psi), (2) the fracture strength of the fibers is 3500 MPa (5 x 105 psi), and (3) the matrix stress at composite failure is 5.5 MPa (800 psi). MPa

Answer 1

sol! - Given data Diameter da 0.0 135 mm Length 1.58 mm Volume fraction of fiber v=0.33 Fiber - matrix bond strength apa 100 MPG fracture strength of fiber F = 3500 MPa Matrix stress of composite failure am =5.5 MPa ord critical fiber Length Le = 2T 3500 X 0.0135 2 (100) 47.25 200 0.236 mm the fiber length of 0.236 mm is much Less the 1.58 mm SO we use since critical than provided Length in the problem 0% can the following Ervation for solving Longitudinal Tensile strength co =fu (i tm Cr-Vf) (0.33) (- + 5.5 2(1.58) (0.9253) - 3500 01236 1155 + 1.815 1068.7215 + 1.815 - 1070.53 MPG *. oed 1070.53 MPa