Applications of the Average Stress Failure Criterion: Part II — Compression

Abstract

Results are presented for the compressive fracture strength of several Gr/Ep (AS/3501-5) laminates containing countersunk holes with both loaded and unloaded fasteners in place. Finite element stress analyses are presented which approximate the countersink geometry and the elastic contact problem. The average stress failure criterion is successfully used to predict the observed strengths in all cases considered. SCOPE N A NUMBER of recent papers [1, 2, 3, 4, 5] , the average stress failure criterion was found to result in reasonably accurate strength predictions for composite laminates containing cutouts and subjected to uniaxial tensile loads. Despite the fact that the rationale behind the average stress failure criterion would appear to be equally applicable to compressive failure, it appears that no attempts at predicting compressive fracture strengths of laminates containing cutouts have been made using this criterion.In the present paper, the results of a series of uniaxial compressive tests are presented for graphite/epoxy laminates containing countersunk fastener holes in

Interactive effect between warp and weft of a woven ramie fabric under biaxial loadings

“…The biaxial relationship of stress-strain behaviors of orthotropic woven composites as well as their uniaxial engineering failure criteria have been investigated (Nuismer, 1979;Surya, Kazuaki, & Ignaas, 2003;Whiteny & Nuismer, 1974). Kawabata, Niwa, and Kawal (1973) further presented the nonlinear behavior and failure mechanism of woven fabrics under biaxial loading.…”

An investigation of graphite PEEK composite under compression with a centrally located circular discontinuity

“…In 1979 Nuismer and Labor attempted to apply the Whitney and Nuismer point stress criterion to compressive responses in a composite to predict a composite's strength and state of stress [18]. In 1986, S.C. Tan utilized a complex variable analysis in order to compute the stress around a hole when a composite is under compression [19].…”

“…Timeshenko and Gere determined a total energy criterion based on the Fourier series formulation of fiber waviness. Frost [20] modified equation (18) to determine the approximate fiber shape at any time during the loading procedure until failure starts to occur. The difference between the initial fiber displacement and subsequent fiber displacements gives us the amount of change in fiber displacement:…”

“…Since w i is similar to V in equation (18), then V will be. used from now on in the place of w i The strain energy due to matrix extension is the tension in the matrix res, iting from the relative lateral displacement of the adjacent fibers.…”

The Failure Characterization of Composite Pinned Joints

“…However, the joints often required for fitting composite parts usually constitute a region of weakness, which can lead to premature failure of structures. Based on the fact that the structural efficiency of a composite structure depends on its joints rather than the component members, the stresses associated with mechanical joining of composites has received much attention in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Mechanical joining includes bolted, riveted, and pinned joints; these joints are prone to high stress concentration, which occurs in the vicinity of the hole, and are often the source of premature failure in composite structures containing joints.…”