Flexure of simply curved composite shapes

Kedward, Keith T.; Wilson, R; McLean, S.K.

doi:10.1016/0010-4361(89)90911-7

Cited by 97 publications

(36 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second case is bending of curved laminates, which generates interlaminar normal stresses [3]. These will be tensile if the moment is tending to reduce the curvature as shown in the figure, and become more significant as the ratio of thickness to radius increases.…”

Section: (B) Overall Interlaminar Stresses Owing To Geometrymentioning

confidence: 99%

The role of delamination in failure of fibre-reinforced composites

Wisnom

2012

Phil. Trans. R. Soc. A.

228

119

View full text Add to dashboard Cite

The mechanisms by which delamination contributes to the failure of fibre-reinforced composites are reviewed. Through-thickness failure owing to interlaminar stresses is considered first, and the effect of delamination in impact and compression after impact. The way in which in-plane failure can occur by delamination and matrix cracks joining up to produce a fracture surface without the need to break fibres is considered next. Examples of quasi-isotropic laminates loaded at different off-axis angles, and with different numbers and thicknesses of ply blocks show large differences in unnotched tensile strength controlled by delamination from the free edge. Similar mechanisms determine the strength of notched specimens and give rise to the hole size effect, whereby tensile strength increases with decreasing hole diameter owing to increased delamination and splitting. Open hole tension and over-height compact tension tests with constant inplane dimensions show a transition in failure mode with increasing ply block thickness from fibre-dominated fracture to complete delamination. In all these cases, the critical factor controlling strength is the relative propensity to delaminate.

show abstract

Section: (B) Overall Interlaminar Stresses Owing To Geometrymentioning

confidence: 99%

The role of delamination in failure of fibre-reinforced composites

Wisnom

2012

Phil. Trans. R. Soc. A.

228

119

View full text Add to dashboard Cite

show abstract

“…However, all the tested examples converged for n ≤ 5. Figure 15 shows a comparison between the HellingerReissner models with n = 1 and n = 5, the FE solution and two first-order shear deformation theory models, namely the Timoshenko curved beam model [17] and a Lekhnitskii-type curved beam model by Kedward et al [18]. The first-order Timoshenko and a Lekhnitskii-type curved beam models match very well with the Hellinger-Reissner model for n = 1.…”

Section: Convergence Analysismentioning

confidence: 79%

“…However, these models are much less accurate than the HellingerReissner model for n = 5. Figure 15: Hellinger-Reissner model results for σ ϕ at ϕ = ψ 0 /2 with modeling order n = 1 and n = 5 compared to 3D FE, Timoshenko curved beam [17] and Lekhnitskii-type curved beam results [18].…”

Section: Convergence Analysismentioning

confidence: 99%

“…The results of the new model are compared with a high fidelity 3D FE model in section 3. Further, the results are compared with closedform first-order models by Timoshenko [17] and Kedward et al [18]. A convergence study is presented to obtain the modeling order required to calculate accurate stress fields for the laminations and geometries studied herein.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Higher-order beam model for stress predictions in curved beams made from anisotropic materials

Thurnherr

Groh

Ermanni

2016

International Journal of Solids and Structures

View full text Add to dashboard Cite

A higher-order beam model for analyzing the flexural response of curved multilayered beams with constant curvature and arbitrary constant thickness is developed. The new model is derived from the Hellinger-Reissner mixed variational statement and predicts inherently equilibrated 3D stresses from an equivalent single-layer model. As a starting assumption, the hoop stress is formulated as a series of higher-order stress resultants multiplied by Legendre polynomials. The governing equations are derived in a generalized manner such that the modeling order can be adjusted and is not defined a priori. Hence, the highest order Legendre polynomial determines the modeling order. The through-thickness shear and normal stresses are derived by integrating the generalized hoop stress in Cauchy's polar equilibrium equations. As a result, all stress fields are based on the same set of variables, thereby considerably reducing the computational effort. The three stress fields, and two displacements in the radial and hoop directions are used in the Hellinger-Reissner functional to derive a new set of stress-displacement relations. The enforcement of the classical membrane and bending equilibrium equations of curved beams in the Hellinger-Reissner functional guarantees that all interlaminar and surface traction equilibrium conditions are satisfied exactly. A validation study of a composite laminate using a high-fidelity 3D finite element model shows that the stresses are captured very accurately by the present model, but with much less computational effort than the finite element model. As a result, the developed model can provide rapid and accurate insights into the expected damage onset behavior of curved laminates.

show abstract

“…The two basic methods for interlaminar tensile/compressive testing include various versions of waisted coupons for axial loading, Figure 9a, and coupons achieving interlaminar tensile stresses through flexure of curved beams, Figure 9b [17]. [17] © Elsevier.…”

Section: Tensile and Compressive Testingmentioning

confidence: 99%

A survey of test methods for multiaxial and out-of-plane strength of composite laminates

Olsson¹

2011

Composites Science and Technology

View full text Add to dashboard Cite

To cite this version:Robin Olsson. A survey of test methods for multiaxial and out-of-plane strength of composite laminates.Composites Science and Technology, Elsevier, 2011, 71 (6) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and other textile systems. Tubular and cruciform specimens can provide arbitrary inplane loading, while off-axis and angle-ply specimens provide specific biaxial loadings.Tensile and compressive out-of-plane strength may be determined by axial loading of specimens with a waisted gauge section, while bending of curved specimens allow determination of the out-of-plane tensile strength. Tests suited for out-of-plane shear strength include the short beam shear test, the inclined double notch test and the inclined waisted specimen. Testing of arbitrary tri-axial stress states using tubular or cruciform specimens with superimposed through-the-thickness loading is highly complex and significant problems have been reported in achieving the intended stress states and failure modes. Specific tri-axial stress states can be obtained by uniaxial loading of specimens with constrained expansion, as in the die channel test.

show abstract

Flexure of simply curved composite shapes

Cited by 97 publications

References 2 publications

The role of delamination in failure of fibre-reinforced composites

The role of delamination in failure of fibre-reinforced composites

Higher-order beam model for stress predictions in curved beams made from anisotropic materials

A survey of test methods for multiaxial and out-of-plane strength of composite laminates

Contact Info

Product

Resources

About