Fracture Mechanics of Matrix Cracking and Delamination in Glass/epoxy Laminates

Fracture Mechanics of Matrix Cracking and Delamination in Glass/epoxy Laminates PDF Author: M. Caslini
Publisher:
ISBN:
Category :
Languages : en
Pages : 46

Get Book Here

Book Description
This study focused on characterizing matrix cracking and delamination behavior in multidirectional laminates. Static tension and tension-tension fatigue tests were conducted on two different layups. Damage onset, accumulation, and residual properties were measured. Matrix cracking was shown to have a considerable influence on residual stiffness of glass epoxy laminates, and could be predicted reasonably well for cracks in 90 deg plies using a simple shear lag analysis. A fracture mechanics analysis for the strain energy release rate associated with 90 deg ply matrix crack formation was developed and was shown to correlate the onset of 90 deg ply cracks in different laminates. The linear degradation of laminate modulus with delamination area, previously observed for graphite epoxy laminates, was predicted for glass epoxy laminates using a simple rule of mixtures analysis. The strain energy release rate associated with edge delamination formation under static and cyclic loading was difficult to analyze because of the presence of several contemporary damage phenomena. Keywords: Fatigue(Mechanics), and Stiffness loss.

Fracture Mechanics of Matrix Cracking and Delamination in Glass/epoxy Laminates

Fracture Mechanics of Matrix Cracking and Delamination in Glass/epoxy Laminates PDF Author: M. Caslini
Publisher:
ISBN:
Category :
Languages : en
Pages : 46

Get Book Here

Book Description
This study focused on characterizing matrix cracking and delamination behavior in multidirectional laminates. Static tension and tension-tension fatigue tests were conducted on two different layups. Damage onset, accumulation, and residual properties were measured. Matrix cracking was shown to have a considerable influence on residual stiffness of glass epoxy laminates, and could be predicted reasonably well for cracks in 90 deg plies using a simple shear lag analysis. A fracture mechanics analysis for the strain energy release rate associated with 90 deg ply matrix crack formation was developed and was shown to correlate the onset of 90 deg ply cracks in different laminates. The linear degradation of laminate modulus with delamination area, previously observed for graphite epoxy laminates, was predicted for glass epoxy laminates using a simple rule of mixtures analysis. The strain energy release rate associated with edge delamination formation under static and cyclic loading was difficult to analyze because of the presence of several contemporary damage phenomena. Keywords: Fatigue(Mechanics), and Stiffness loss.

Study of Matrix Cracking and Delamination in Glass/Epoxy Laminates

Study of Matrix Cracking and Delamination in Glass/Epoxy Laminates PDF Author: M. Caslini
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 10

Get Book Here

Book Description
This study focused on characterizing matrix cracking and delamination behavior in multidirectional laminates. Static tension and tension-tension fatigue tests were conducted on two different layups. Damage onset, accumulation, and residual properties were measured. Matrix cracking was shown to have a considerable influence on residual stiffness of glass epoxy laminates and could be predicted reasonably well for cracks in 90° plies using a simple shear lag analysis. A fracture mechanics analysis for the strain energy release rate associated with 90° ply matrix crack formation was developed and was shown to correlate the onset of 90° ply cracks in different laminates. The linear degradation of laminate modulus with delamination area, previously observed for graphite epoxy laminates, was predicted for glass epoxy laminates using a simple rule of mixtures analysis. The strain energy release rate associated with edge delamination formation under static and cyclic loading was difficult to analyze because of the presence of several contemporary damage phenomena.

Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking

Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36

Get Book Here

Book Description


Delamination Fracture Toughness and Acoustic Emission in Fiber-reinforced Epoxy Laminates

Delamination Fracture Toughness and Acoustic Emission in Fiber-reinforced Epoxy Laminates PDF Author: Hamid Saghizadeh
Publisher:
ISBN:
Category :
Languages : en
Pages : 270

Get Book Here

Book Description


Combined Effect of Matrix Cracking and Stress-free Edge on Delamination

Combined Effect of Matrix Cracking and Stress-free Edge on Delamination PDF Author: Satish Annaji Salpekar
Publisher: DIANE Publishing
ISBN: 1428916741
Category : Composite materials
Languages : en
Pages : 68

Get Book Here

Book Description


Fracture Mechanics of Transverse Cracks and Edge Delamination in Graphite-Epoxy Composite Laminates

Fracture Mechanics of Transverse Cracks and Edge Delamination in Graphite-Epoxy Composite Laminates PDF Author: A. S. D. Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 167

Get Book Here

Book Description
The fracture mechanics of matrix-dominated cracks--multiple transverse cracks and edge delamination--has been presented in this report. Analytical models are developed which describe the initiation, growth and the growth stability of these two types of cracking mechanisms. A finite element crack-closure method is used to simulate the crack growth numerically; and an extensive experimental case study is conducted to correlate with the analytical models. (Author).

Damage and Fracture of Composite Materials and Structures

Damage and Fracture of Composite Materials and Structures PDF Author: Mohd Nasir Tamin
Publisher: Springer Science & Business Media
ISBN: 3642236596
Category : Science
Languages : en
Pages : 244

Get Book Here

Book Description
This monograph presents recent research findings on fracture properties and behavior of the composites, and their damage and cracking process under both quasi-static and impact loading conditions. Theoretical treatment, experimental investigation and numerical simulation aspects of the mechanics of composites, including sandwich structures are included.

Matrix Cracking-Induced Delamination Propagation in Graphite/Epoxy Laminated Composites Due to a Transverse Concentrated Load

Matrix Cracking-Induced Delamination Propagation in Graphite/Epoxy Laminated Composites Due to a Transverse Concentrated Load PDF Author: S. Liu
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 16

Get Book Here

Book Description
An investigation was performed to study the delamination propagation induced by matrix cracking in graphite/epoxy laminated composite beams subjected to transverse concentrated loading. The major focus of the study was to fundamentally understand the interaction between matrix cracking and delamination propagation in laminated composites resulting from transverse loadings. A nonlinear finite element analysis combined with a failure criterion and fracture mechanics was developed for modeling the damage initiation and propagation in composite beams subjected to a concentrated line load. A contact analysis based on the Lagrange multiplier technique was also adopted for modeling the contactslip condition of delamination and matrix crack surfaces during loading. Results of the calculations based on the analysis were compared favorably with the existing data and the data generated during the investigation.

Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking

Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722082970
Category :
Languages : en
Pages : 34

Get Book Here

Book Description
Several two dimensional finite element analyses of (0 sub 2/90 sub 8/0 sub 2) glass/epoxy and graphite-epoxy composite laminates were performed to study some of the characteristics of damage development due to an impact load. A cross section through the thickness of the laminate with fixed ends, and carrying a transverse load in the center was analyzed. Inclined matrix cracks such as those produced by low velocity impact were modeled in the 90 deg ply group. The introduction of the matrix cracks caused large interlaminar tension and shear stresses in the vicinity of both crack tips in the 0/90 and 90/0 interfaces. The large interlaminar stresses at the ends of the matrix cracks indicate that matrix cracking may give rise to delamination. The ratio of mode I to total strain energy release rate at the beginning of delamination calculated at the two matrix crack tips was 60 and 28 pct., respectively, in the glass/epoxy laminate. The corresponding ratio was 97 and 77 pct. in the graphite-epoxy laminate. Thus, a significant mode I component of strain energy release rate may be present at the delamination initiation due to an impact load. Salpekar, S. A. Unspecified Center NAS1-19399; NAS1-18599; RTOP 505-63-50-04...

Combined Effect of Matrix Cracking and Stress-Free Edge on Delamination

Combined Effect of Matrix Cracking and Stress-Free Edge on Delamination PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722304362
Category :
Languages : en
Pages : 68

Get Book Here

Book Description
The effect of the stress-free edge on the growth of local delaminations initiating from a matrix crack in (0 sub 2/90 sub 4) sub s and (+ or - 45.90 sub 4) sub s glass epoxy laminates is investigated using 3-D finite element analysis. The presence of high interlaminar normal stresses at the intersection (corner) of the matrix crack with the stress-free edge, suggests that a mode I delamination may initiate at the corners. The strain energy release rates (G) were calculated by modeling a uniform through-width delamination and two inclined delaminations at 10.6 deg and 45 deg to the matrix crack. All components of G have high values near the free edges. The mode I component of G is high at small delamination length and becomes zero for a delamination length of one-ply thickness. The total G values near the free edge agreed well with previously derived closed form solution. The quasi-3D solutions agreed well with the 3-D interior solutions. Salpekar, S. A. and Obrien, T. K. Langley Research Center...