Fracture of Random Short-Fiber SMC Composite

Abstract

The fracture behavior of random chopped-strand, glass-fiber reinforced SMC composites was studied. Experiments were conducted on notched SMC-R50 composite plates subjected to inplane loading. Fracture mechanics analyses based on recently developed conservation laws of solid mechanics were performed to evaluate notch-tip stress intensities in the specimens. Fracture toughnesses, K IQ and K IIQ , of this material under individual mode-I and mode-II loading were determined. Fracture tests and subsequent analyses were also conducted on the notched SMC-R50 subjected to combined-mode loading. Mixed-mode fracture criteria were investigated for the random short-fiber composite. The suitability of the Whitney-Nuismer two-parameter model was also examined for determination of notched SMC composite strength.

Analysis of pure mode III and mixed mode (III+II) interlaminar crack growth in polymeric woven fabrics

“…1). In the last four decades the attention of researchers was focused mostly on the mode I fracture of short fiber composites [1], glass/epoxy laminate [2] and woven composite materials [3]. Mode II delamination has received some attention with the development of some well established tests [4,5].…”

Fracture of knitted randomly oriented short-fiber composite

“…The use of the mode-II fracture specimens has been attempted by Wang et al [10] for studying general anisotropic composites using an anisotropic elasticity solution with the aid of a numerical method. The proper specimen geometry (e.g.…”

“…the angle of the V-notch and the ratio of notch depth to specimen width) has been determined for various cases with different degrees of composite anisotropy [15]. The mixed-mode fracture specimens used in this study are of the same type as those in [10]. Since no explicit mathematical relationship is currently available for determining the macroscopic critical stress intensity factors in finite-dimensional composite panels under mixed-mode loading, an approach with combined fracture experiments and the anisotropic elasticity solution aided by a suitable numerical scheme developed in [16] is used to analyze the mode-II and mixed-mode fracture problems in the composite.…”

“…Approximate analytical solutions, the compliance method and the R-curve concept have also been used for this purpose. For example, a series of studies on sheet molding compounds (SMC) of various short glass fiber reinforced polyesters have been conducted in the framework of this concept, and the validity and limitations of this approach have been discussed [7][8][9][10]. Furthermore, fracture of the random short fiber composites under different loading modes, i.e., the opening-mode, mode-II and mixed-mode fracture, has been studied [10] in conjunction with an M-integral crack analysis.…”

Shear Fatigue Degradation and Fracture of Random Short-Fiber SMC Composite

“…Concluding remarks derived from the study are presented in Section 4. Extension and modification of this kind of specimen and test for studying shear fracture toughness of the random short-fiber SMC material are reported in [15].…”