Failure behavior of composite laminates under four-point bending

Abstract

In this study, failure behavior of fiber-reinforced composites under four-point bending is investigated. First, the tests are modeled analytically using the classical lamination theory (CLT). The maximum allowable moment resultants of [ 12 ] T offaxis laminate as well as balanced and symmetric angle-ply [ 3 /À 3 ] s composite laminates as a function of fiber orientation angle, , are obtained using Tsai-Wu, maximum stress, maximum strain, Hashin, Tsai-Hill, Hoffman, quadric surfaces, modified quadric surfaces, and Norris failure criteria. Second, the same tests are simulated using the finite element method (FEM). Thermal residual stresses are calculated and accounted for in the failure analysis. An analysis is conducted for optimal positioning of the supports so as to ensure that intralaminar failure modes dominate interlaminar (delamination) failure mode. A test setup is then constructed accordingly and experiments are conducted. The correlation of the predicted failure loads and the experimental results is discussed. The quadric surfaces criterion is found to correlate better with the experimental results among the chosen failure criteria for the selected configurations.

Co-cured manufacturing of multi-cell composite box beam using vacuum assisted resin transfer molding

“…Essentially, this was often reported in the previous studies for composite structures. 37,38 Subsequently, the second cracks were initiated on the right side-web at the upper loading region, which was similar to the development of the first crack (Figure 7(b), status B) and occurred at 35 ± 1 kN of loading with a peak in the strain measurement (Figure S2). In Experiment 1, 2, and 3, these two cracks propagated through the thickness predominantly in tensile fracture mode (Mode I) as the travel of the load head increased and caused damages on the side webs, which weakened the section under the load head.…”

Effect of Fibre Orientation and Hostile Solutions on Stress Relaxation of Glass/Polyamide Composites

“…For laminates with 0 • oriented fibres, the fibre breakage is the main failure mode identified, and the posterior data zigzag corresponds to the initiation of delamination's propagation. For the other orientations, the failure mode is essentially based on matrix and/or fibre/matrix interface degradations that are evidenced by smoother curves [51]. However, the high stress concentration in the pin load contact region should not be neglected in all failure mechanisms [52].…”

Failure analysis of delaminated carbon/epoxy composite under pure bending: validation with numerical analysis

“…In fact, this bending moment induces both tensile and compressive stresses across the beam section. Hence, Hashin criterion may be valid for bending problems (Koc et al , 2016). The failure takes place under the conditions of plane stress case when one of the expressions given below is satisfied.…”