Biaxial Testing and Failure Mechanisms in Tubular G-10 Composite Laminates

AbstractThis paper reviews findings on the type, morphology and constitutive behaviour of impact damage zones during loading after impact and their effect on the laminate strength and stability. The paper is limited to tape prepreg based monolithic laminates, although some similarities exist with impact damage in textile based laminates. Damage zones have a complex geometry with several damage types, which results in an interaction and competition between different failure mechanisms, e.g. local and global buckling, compressive failure, and delamination growth. Hence, simplified damage models may provide incorrect predictions of the failure load and failure mechanisms after impact. The constitutive behaviour of damage zones has been studied experimentally in tension and compression using an inverse method, and the results have been compared with detailed FE models of a generic impact damage. The paper is concluded with a discussion on analytical and computational models to predict the resulting strength of impacted laminates.

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Deformation and Failure Behavior of Woven Composite Laminates

Journal of Engineering Materials and Technology ◽

10.1115/1.2904277 ◽

1994 ◽

Vol 116 (2) ◽

pp. 222-232 ◽

Cited By ~ 69

Author(s):

M. Karayaka ◽

P. Kurath

Keyword(s):

Composite Laminates ◽

Failure Mechanisms ◽

Elastic Stiffness ◽

Experimental Program ◽

Internal Stresses ◽

Failure Behavior ◽

Deformation Model ◽

Deformation And Failure ◽

Linear Elastic ◽

Proposed Model

Conceptually, fabric composites have some structural advantages over conventional laminates. However, deformation and failure analyses become more complex with the additional anisotropy introduced by the weaving geometry. A micromechanistic deformation model, that could realistically be incorporated into structural finite element codes, is proposed where loading direction and weave parameters are allowed to vary. Comparisons are made to previous models and experimental results for woven materials, indicating that the proposed model provides improved estimates for the linear elastic stiffness. The model further provides predictions for internal stresses in the longitudinal, transverse, and interlace regions of the woven laminate which qualitatively correspond to the experimentally observed failure mechanisms. The experimental program investigates deformations behavior and failure mechanisms of 5-harness 0/90 weave Graphite/Epoxy laminates under tension, compression, and 3-point and 4-point bending loading. Under these conditions the woven laminates exhibit orientation dependent mechanical properties and strength.

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Design of a cruciform specimen for biaxial testing of fibre reinforced composite laminates

Composites Science and Technology ◽

10.1016/j.compscitech.2005.08.011 ◽

2006 ◽

Vol 66 (7-8) ◽

pp. 964-975 ◽

Cited By ~ 109

Author(s):

A. Smits ◽

D. Van Hemelrijck ◽

T.P. Philippidis ◽

A. Cardon

Keyword(s):

Composite Laminates ◽

Biaxial Testing ◽

Cruciform Specimen ◽

Reinforced Composite

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A micromechanics-based damage model for compressive behavior analysis of impacted composite laminates

International Journal of Damage Mechanics ◽

10.1177/1056789519843622 ◽

2019 ◽

Vol 29 (3) ◽

pp. 369-387 ◽

Cited By ~ 1

Author(s):

Xiaofei Lou ◽

Xuecheng Han ◽

Hongneng Cai

Keyword(s):

Compressive Strength ◽

Impact Loading ◽

Composite Laminates ◽

Failure Mechanisms ◽

Damage Model ◽

Failure Criteria ◽

Matrix Cracking ◽

Compressive Behavior ◽

Isotropic Composite ◽

The Matrix

The compressive strength of composite laminates decreases seriously after being subjected to impact loading, which is an important item to be considered in the usage of composite material. In this paper, a micromechanics-based damage model is proposed to study the compressive behavior of impacted composite laminates. The micro stresses of fiber and matrix are calculated by stress amplification factors and then used to judge the failure mechanisms according to corresponding physical failure criteria. A progressive damage model based on different failure statuses of constituents is established to study the degradation of material properties. The bi-linear cohesive model is used in the research of delamination onset and propagation. The compressive behaviors of quasi-isotropic composite laminates subjected to different impact energies are investigated by this proposed method. Good agreements in terms of structure responses, failure mechanisms, and residual compressive strengths are obtained between numerical results and experimental data. The matrix cracking and delamination caused by impact loading are responsible for the initiation and propagation of buckling, which leads to the final collapse of entire laminates. Based on the numerical investigations of material parameters, the increment of mode II interlaminar fracture toughness is capable of improving the residual compressive strength significantly.

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A Study on the Failure Mechanisms of Composite Laminates Simultaneously Impacted by Two Projectiles

Advanced Composites Letters ◽

10.1177/096369351802700302 ◽

2018 ◽

Vol 27 (3) ◽

pp. 096369351802700

Author(s):

Sun Xiao-Yu ◽

Teng Jian-Xin ◽

He Zheng ◽

Gu Xuan

Keyword(s):

Composite Laminates ◽

Damage Mechanics ◽

Single Point ◽

Failure Mechanisms ◽

Damage Model ◽

Continuum Damage Mechanics ◽

Interface Elements ◽

Model Combining ◽

Low Energies ◽

The Impact

With most studies concentrated on the single point isolated impact events, this work mainly investigates the failure mechanisms of composite laminates simultaneously impacted by two projectiles over low energies. A 3D intralaminar damage model combining continuum damage mechanics to analyze the in-ply damage and cohesive interface elements to simulate the delamination are applied to model the damage evolution of E-glass/epoxy composites simultaneously impacted by two projectiles. The damage model is incorporated into the Abaqus/Explicit by the subroutine VUMAT. A comparison between the simulated predictions and the experimental observations of laminates impacted by one projectile is made to verify the reasonability of the damage model applied. The simulation results indicate that the delamination initiation is not largely affected by the impact energy and the number of the projectiles. As the combined effects of the two projectiles on the laminate, the intersection of matrix damage areas in plies and the connection of delamination regions at interfaces, largely decrease the overall stiffness of the laminate and result in more serious damage.

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