... Two different finite element models have been applied to the analysis of delamination growth in a multidirectional graphite/epoxy ENF specimen, which has previously been investigated experimentally. For a more accurate computation of energy release rates along the delamination front...

... and/or the manufacturing process, additional testing should be performed on panels manufactured from different sources. composite materials graphite/epoxy transverse tensile strength flexural fatigue Weibull statistics Ann W. P e c k I An Experimental Investigation of Transverse Tension Fatigue...

... tube design. An understanding of the damage mechanisms involved is critical in the determination of composite structural integrity and for the development of damage models and design codes. To this end, a test program was conducted to characterize the impact response of graphite/epoxy structures...

... The characterization of interlaminar fracture—with the goal to obtain a database that can be used in design—is demonstrated for a first generation graphite/epoxy composite widely used by European aircraft manufacturers. Critical energy release rates for Mode I and Mode II failure have been...

... The effect of the stress ratio on the propagation behavior of Mode II interlaminar fatigue cracks was studied with unidirectional graphite/epoxy laminates, Toray T800H/#3631. End-notched flexure (ENF) specimens were used for fatigue tests under the stress ratios of R = 0.2, 0.5, and 0.6...

...°, +15/−15°, +15/+15°, +30/−30°, and +30/+30° plies in a typical graphite/epoxy. A previously developed “ENF test design procedure” is used to aid in the determination of specimen stacking sequences and test geometries, such that delamination growth occurs at the interface of interest, yet...

... on composite tensile and compressive strength. Both tensile and compressive strength were unaffected by the mat interleaf. polymer matrix composites interleaved composites graphite/epoxy end notch flexure ENF Eileen Armstrong- Carrolll and Roland Cochran 1 Improvement of Delamination Resistance...

... delamination energy release rate crack tip element fracture graphite/epoxy Barry D. Davidson I Prediction of Energy Release Rate for Edge Delamination Using a Crack Tip Element Approach REFERENCE: Davidson, B. D., "Prediction of Energy Release Rate for Edge Delamination Using a Crack Tip Element...

... The effect of free-edge stresses on the fatigue of graphite/epoxy laminates was evaluated numerically and experimentally. Reported are results of static and compression-dominated ( R = -3.75) fatigue tests on AS4/3501-6 and IM6/5245C using unnotched specimens. Two different stacking sequences...

... An investigation of the damage tolerance and damage arrest characteristics of internally pressurized graphite/epoxy tape cylinders with axial notches was conducted. An existing failure prediction methodology, developed and verified for quasi-isotropic graphite/epoxy fabric cylinders...

... with experimental data for graphite/epoxy systems also. The shear deformation model can also be applied to other laminate configurations, for example, (±25/90 n ) s type. transverse cracking graphite/epoxy glass/epoxy shear deformation fracture mechanics P. Sriram 1 and Erian A. Armanios 2 Shear...

... Surface preparations of graphite/epoxy composites for adhesive bonding were mechanically tested and fractographically examined. Two adhesives (FM73 and FM300), two peel plies (porous teflon and Release E), and three surface preparations (peel ply, sanding, and an application of a release agent...

... Stitched uniwoven graphite/epoxy laminates show great promise as a damage-tolerant composite material which is easily fabricated into large net-shaped parts and structures. They also offer the potential of being less costly than other damage-tolerant systems such as toughened matrix composites...

... A test program was conducted to compare the tensile behavior of laminates made with graphite fibers and a low strain-to-failure matrix system (epoxy) versus a high strain-to-failure matrix system (PEEK), in the presence of notches. Graphite/epoxy (AS4/3501-6) and graphite/PEEK (AS4/APC-2...

... Crack growth from notched unidirectional graphite/epoxy tubes subjected to axial, torsional, and combined loading conditions was studied experimentally and theoretically. Tubes with fiber orientations of 2.5, 15, 45, and 87.5° were notched with slots 0.5 cm long, parallel to the tube axis...

... The environmental effects of water and jet fuel absorption on AS4/3501-6 graphite/epoxy were measured in terms of the changes in the interlaminar fracture toughness. Saturated double cantilever beam (DCB) and end notched flexure (ENF) specimens were tested to determine the environmental effects...

... The effects of stress ratio on delamination onset behavior under cyclic loading was investigated in AS4/3502 [+/-25 2 /90] s graphite/epoxy laminates. For the purpose of this study, delamination onset was defined as a delamination 5% of the laminate width. The resulting data showed definite...

... The influence of material volume on the transverse tensile strength of AS4/3501-6 graphite/epoxy composites was investigated. Tension tests of 90° laminates with three different widths and five different thicknesses were conducted. A finite element analysis was performed to determine...

... Graphite/epoxy specimens with two different quasi-isotropic layups ([0/45/90/ - 45] s and [0/±60] s ) were tested in axial compression in an IITRI test fixture using both miniature sandwich specimens and all-laminate coupons. Fractographic examinations of the tested specimens' cross-sections...

... This paper describes recent work in which improved nondestructive evaluation (NDE) techniques for impact damage in graphite/epoxy composites have been used in conjunction with two different approaches to damage modelling to improve prediction of structural response under compressive loading...