Failure Mechanisms of Composite Plates with a Circular Hole under Remote Static Biaxial Planar Compressive Loading

We report the results of an experimental investigation carried out for the analysis of failure mechanisms in fibrous laminated composite plates containing stress raisers, in the form of circular cutouts, under static biaxial planar compressive loading (i.e., compression in the two inplane orthogonal directions). A series of biaxial tests were carried out with 48 ply graphite/epoxy composites of varying fiber orientation. In all cases, the hole diameter to plate width aspect ratio remained in a range suitable for infinite plate assumptions. Fiber microbuckling, fiber kink banding, and fiber/matrix debonding are identified as the dominant failure mechanisms.

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Failure Mechanisms of Notched Laminates Under Biaxial Compression at Elevated Temperature

10.1115/imece2000-2157 ◽

2000 ◽

Author(s):

Junghyun Ahn ◽

Anthony M. Waas

Keyword(s):

Elevated Temperature ◽

Failure Mechanisms ◽

Compressive Loading ◽

Stress Raiser ◽

Laminated Composite ◽

Composite Plates ◽

Biaxial Compression ◽

Laminated Composite Plates ◽

Final Failure ◽

Circular Cutout

Abstract A compression test at elevated temperature was performed to investigate the notch sensitivity and failure mechanisms of fibrous laminated composite plates containing a stress raiser, in the form of a circular cutout, under equi-biaxial and uniaxial compressive loading. Strains measured at various locations on the specimen surface and cutout edge were used to monitor the initiation of failure. Unloading the specimen before global failure made it possible to understand the failure mechanism associated with the final failure mode.

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Stress Concentrations in Cylindrically Orthotropic Composite Plates With a Circular Hole

Journal of Applied Mechanics ◽

10.1115/1.3157675 ◽

1981 ◽

Vol 48 (3) ◽

pp. 563-569 ◽

Cited By ~ 4

Author(s):

N. J. Hoff

Keyword(s):

Closed Form ◽

Circular Hole ◽

Orthotropic Plate ◽

Composite Plates ◽

Stress Concentrations ◽

Orthotropic Composite ◽

Closed Form Solutions ◽

Cylindrically Orthotropic

The equations governing the distribution of the stresses in a cylindrically orthotropic plate with a circular hole are solved for the case when the plate is subjected to uniform uniaxial traction. Closed-form solutions are given for the circumferential stresses along the edge of the hole.

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Investigating the Effect of Stepped Scarf Repair Ratio in Repaired CFRP Laminates under Compressive Loading

Journal of Composites Science ◽

10.3390/jcs4040153 ◽

2020 ◽

Vol 4 (4) ◽

pp. 153

Author(s):

Spyridon Psarras ◽

Theodoros Loutas ◽

Magdalini Papanaoum ◽

Orestis Konstantinos Triantopoulos ◽

Vasilis Kostopoulos

Keyword(s):

Numerical Models ◽

Compressive Loading ◽

Composite Plates ◽

Step Length ◽

Critical Threshold ◽

Cfrp Laminates ◽

Threshold Size ◽

Repair Patch ◽

Parametric Studies ◽

Strength And Stiffness

In this work the effectiveness of stepped repairs to damaged fiber reinforced composite materials is investigated by using previously validated numerical models which were compared with tested repaired composite plates. Parametric studies were carried out in order to assess the scarf ratio (i.e., step length to ply thickness ratio) influence on ultimate forces, displacements, stresses and stiffnesses. FE models with repair scarf ratios varying from the value of 20 to the value 60 with a step increase of 10 were developed. The numerical models allowed a direct comparison of the influence that the scarf ratio had to the strength and stiffness restoration of the repaired composite structure. The study verifies that the restoration of the strength of a damaged laminate depends largely on the size of the repair patch. Generally, the bigger the size of a patch, the stronger the repaired structure is, up to a critical threshold size. To maximize the strength restoration, it is advised that the number of steps in each patch are no less than the number of plies on the base laminate.

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