Testing of angle-ply laminates to obtain unidirectional composite compression strengths

Welsh, Jeffry S.; Adams, Donald F.

doi:10.1016/s1359-835x(96)00138-8

Cited by 21 publications

(25 citation statements)

References 1 publication

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“…The specimen configurations, shown in Figure 2, were (a) a simple unclamped cuboid (CP Cub) similar to the UD Cub design in Figure 1 (a), and (b) a clamped dog-bone specimen (CP DBC) similar to the UD DBC design in Figure 1 (c). Longitudinal material, or ply properties were extracted from the overall axial response using classical lamination theory (CLT) as described in [11].…”

Section: Methodology and Experimental Set-up 21 Specimen Configurationmentioning

confidence: 99%

“…Because of these issues, the extraction of longitudinal ply properties from multidirectional (MD) or cross-ply (CP) laminates, using classical lamination theory (CLT) has been suggested as a more viable alternative [6,10,11]. However, previous experimental studies have always shown significant differences between the strength measurements obtained from UD and MD laminates.…”

Section: Introductionmentioning

confidence: 99%

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A study on the longitudinal compression strength of fibre reinforced composites under uniaxial and off-axis loads using cross-ply laminate specimens

Thomson

Cui

Erice

et al. 2019

Composites Part A: Applied Science and Manufacturing

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Longitudinal compression testing of unidirectional FRP laminates remains a challenge due to the difficulty in applying high compressive loads without stress concentrations and boundary effects leading to premature failure. This work aims to critically evaluate different specimen designs and laminate configurations, cross-ply in particular, for the determination of longitudinal compression properties of unidirectional plies. To this end, a comprehensive experimental campaign has been carried out, comparing strength, stiffness, and failure modes across different specimen designs and laminate configurations. The investigated cross-ply specimens produced comparable results without many of the issues observed in the testing unidirectional material and, therefore, are strongly recommended for the determination of longitudinal compressive strength. Finally, the cross-ply material was tested under off-axis compression to study the effects of shear on the longitudinal compression strength using a series of compression specimens cut at different angles between 0 and 15° to the direction of the laminate.

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Section: Methodology and Experimental Set-up 21 Specimen Configurationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A study on the longitudinal compression strength of fibre reinforced composites under uniaxial and off-axis loads using cross-ply laminate specimens

Thomson

Cui

Erice

et al. 2019

Composites Part A: Applied Science and Manufacturing

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“…The brooming failure was frequently observed in our cross-ply and angle-ply specimens. Welsh and Adams indicated that this failure mode is probably a post-failure phenomenon and that a true compressive failure was achieved prior to the brooming effect [3]. The conventional 0° unidirectional composite specimens, typically fail in a fibre micro-buckling mode before the compressive strength of individual fibres is achieved.…”

Section: Resultsmentioning

confidence: 99%

“…The main advantages of this method are [1]: -the combined load allows to test untabbed straight-sided specimens avoiding high stress concentrations; -the simple test method allows to obtain repeatable results; -the test fixture is small and simple to use (especially not room-temperature ones). The direct experimental determination of compressive strength of a carbon/epoxy unidirectional lamina, through mechanical test of 0° composite laminates, leads to an underestimation due to fibre micro-buckling failure [3]. Then, in this paper, the indirect determination of the compressive strength by testing cross-ply and angle-ply laminates is used.…”

Section: Introductionmentioning

confidence: 99%

Estimate of compressive strength of an unidirectional composite lamina using cross-ply and angle-ply laminates

Scafè¹,

Brentari²,

Dlacic³

et al. 2014

Frattura Ed Integrità Strutturale

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In this work has been estimated the compressive strength of a unidirectional lamina of a carbon/epoxy composite material, using the cross-ply and angle-ply laminates. Over the years various methods have been developed to deduce compressive properties of composite materials reinforced with long fibres. Each of these methods is characterized by a specific way of applying load to the specimen. The method chosen to perform the compression tests is the Wyoming Combined Loading Compression (CLC) Test Method, described in ASTM D 6641 / D 6641M-09. This method presents many advantages, especially: the load application on the specimen (end load combined with shear load), the reproducibility of measurements and the experimental equipment quite simplified. Six different laminates were tested in compressive tests. They were realized by the same unidirectional prepreg, but with different stacking sequences: two cross-ply [0/90]ns, two angle-ply [0/90/±45]ns and two unidirectional laminates [0]ns and [90]ns. The estimate of the compressive strength of the unidirectional laminates at 0°, was done by an indirect analytical method, developed from the classical lamination theory, and which uses a multiplicative parameter known as Back-out Factor (BF). The BF is determined by using the experimental values obtained from compression tests.Finally, extrapolated data were compared with prepreg manufacturer datasheet. SOMMARIO.In questo lavoro è stata stimata la resistenza a compressione di una lamina unidirezionale di un composito a fibre di carbonio e matrice epossidica, utilizzando dei laminati cross-ply ed angle-ply. Negli anni sono stati sviluppati vari metodi per la caratterizzazione a compressione di materiali compositi rinforzati a fibre lunghe, ognuno dei quali contraddistinto da una specifica modalità di applicazione del carico al provino. Il metodo scelto per eseguire le prove di compressione è il Wyoming Combined Loading Compression (CLC) Test Method, descritto nella normativa ASTM D 6641/D 6641M-09. Tale metodo presenta molti vantaggi, tra i quali: la modalità di applicazione del carico sul provino (combinazione di carico di taglio e di estremità), la riproducibilità delle misure e la facilità di utilizzo del telaio Wyoming. Sono stati testati a compressione sei laminati, realizzati a partire da uno stesso prepreg unidirezionale: due crossply [0/90]ns ognuno con una diversa sequenza di laminazione, due angle-ply [0/90/±45]ns ognuno con una diversa sequenza di laminazione e due laminati con fibre solo a 0° od a 90°. Il calcolo della resistenza a compressione della lamina unidirezionale a 0°, è stato fatto utilizzando un metodo analitico indiretto, sviluppato a partire dalla teoria classica della laminazione e che fa uso di un parametro moltiplicativo noto come Back-out Factor (BF). Il BF viene determinato utilizzando i valori sperimentali ricavati dalle prove di compressione. Infine i valori di resistenza così ottenuti sono stati comparati con quelli presenti nella scheda tecnica fornita dal produttore del prepreg.

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“…In general, unidirectional laminates give low compressive strengths due to instability during failure. There has been significant interest (Camponeschi and Hoyns 1991;Wilson et al 1994;Welsh and Adams 1996;Welsh and Adams 1997) in testing angleply or cross-ply composite laminates and Òbacking-outÓ the unidirectional strength of the material. The use of the back-out factor to calculate unidirectional strength assumes that the compressive failure is controlled solely by the axial stress in the 0 ¡ ply.…”

Section: Introductionmentioning

confidence: 99%

Effect of an Angle-Ply Orientation on Compression Strength of Composite Laminates

Hoppel¹,

Teresa²

1999

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March 1999This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. PREPRINT Effect of Angle-Ply Orientation on Compression Strength of Composite LaminatesChristopher P. R. Hoppel This work has implications in the selection of composite failure criterion for compression performance, design of test coupons for acceptance testing, and the selection of laminate architectures for optimum combinations of compressive and shear behavior. Two commonly used composite failure criteria, the maximum stress and the Tsai-Wu, predict significantly different laminate strengths depending on the PoissonÕs ratio of the laminate. This implies that the biaxial stress state in the laminate needs to be carefully considered before backing out unidirectional properties.

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Testing of angle-ply laminates to obtain unidirectional composite compression strengths

Cited by 21 publications

References 1 publication

A study on the longitudinal compression strength of fibre reinforced composites under uniaxial and off-axis loads using cross-ply laminate specimens

A study on the longitudinal compression strength of fibre reinforced composites under uniaxial and off-axis loads using cross-ply laminate specimens

Estimate of compressive strength of an unidirectional composite lamina using cross-ply and angle-ply laminates

Effect of an Angle-Ply Orientation on Compression Strength of Composite Laminates

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