Contribution to the problem of tensile and bending-test method for SiC-fibre-reinforced glass

The Young's moduli of SiC-fiber-reinforced DURAN glass composites with different fiber concentrations obtained from tensile and three-point-bending tests were shown to be in good agreement, while the values of strength and bendover stress and strain were larger in the bending test than in the tensile test. It is assumed that this difference is mainly a consequence of the larger effectively stressed sample volume in the tensile-stress test, compared to the bending test, and it is a consequence of the shift of the neutral line in the bending test toward the compressive-stress region during the fracture process. The second consequence is the reason why the samples behave in a much more ductile way in the bending test and are brittle in the tensile test. The advantages and disadvantages of the two methods are discussed and demonstrated with special regard to the composites mentioned.