Download or read book Fracture Mechanics of Matrix Cracking and Delamination in Glass epoxy Laminates written by M. Caslini and published by . This book was released on 1986 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Study of Matrix Cracking and Delamination in Glass Epoxy Laminates written by M. Caslini and published by . This book was released on 1987 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking written by and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Delamination Fracture Toughness and Acoustic Emission in Fiber reinforced Epoxy Laminates written by Hamid Saghizadeh and published by . This book was released on 1987 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Effect of Matrix Cracking and Stress free Edge on Delamination written by Satish Annaji Salpekar and published by DIANE Publishing. This book was released on 1990 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Mechanics of Transverse Cracks and Edge Delamination in Graphite Epoxy Composite Laminates written by A. S. D. Wang and published by . This book was released on 1982 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).

Download or read book Matrix Cracking Induced Delamination Propagation in Graphite Epoxy Laminated Composites Due to a Transverse Concentrated Load written by S. Liu and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Damage and Fracture of Composite Materials and Structures written by Mohd Nasir Tamin and published by Springer Science & Business Media. This book was released on 2012-01-05 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Combined Effect of Matrix Cracking and Free Edge on Delamination written by TK. O'Brien and published by . This book was released on 1991 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of the stress-free edge on the growth of local delaminations initiating from a matrix crack in a composite laminate is investigated using a three-dimensional finite element analysis. Two glass epoxy layups, (02/904)s and (±45/904)s, were modeled with a matrix crack in the central group of eight 90° plies, and delaminations initiating from the matrix cracks in the 0/90 and -45/90 interfaces, respectively. The analysis indicated that high tensile interlaminar normal stresses were present at the intersection (corner) of the matrix crack with the stress-free edge, suggesting that an opening (Mode I) delamination may initiate at these intersections.

Download or read book Mixed Mode Failure Based Fracture Mechanics Analysis of Glass epoxy Laminates with a Local Delamination Under Tension torsion Loading written by James Arthur Knittel and published by . This book was released on 1995 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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...

Download or read book Stress Analysis in Cross ply Laminates Damaged by Transverse Matrix Cracks written by Jung Ki Lee and published by . This book was released on 1989 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Effect of Matrix Cracking and Stress Free Edge on Delamination written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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...

Download or read book Hygrothermal Influence on Delamination Behavior of Graphite epoxy Laminates written by and published by . This book was released on 1984 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Delamination in Cross Ply Laminates Initiating from Impact Induced Matrix Cracking written by SA. Salpekar and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several two-dimensional finite element analyses of (02/908/02) glass/epoxy and graphite/epoxy composite laminates were performed to investigate 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 a low-velocity impact, were modeled in the 90° ply group. The introduction of the matrix cracks caused large interlaminar tensile 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, GI/Gtotal, at the beginning of delamination, calculated at the two (top and bottom) matrix crack tips was 60 and 28%, respectively, in the glass/epoxy laminate. The corresponding ratio was 97 and 77% 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. The value of strain energy release rate at either crack tip increased due to an increase in the delamination length at the other crack tip and may give rise to an unstable delamination growth under constant load.

Download or read book Free Edge Stress Analysis of Glass Epoxy Laminates with Matrix Cracks written by JC. Fish and published by . This book was released on 1992 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and analytical study was conducted on the influence of matrix cracking on delamination in (+ 15/90n/-15)s glass-epoxy laminates subjected to monotonically increasing tension loads. Four different layups are examined with the number of symmetric 90° layers varying from 0 to 3 (n = 0, 1, 2, 3). Experimental results show that local delaminations form at the intersection of matrix cracks in the + 15° plies and the free edge. A quasi-three-dimensional (Q3D) finite-element analysis is used to examine free-edge stresses in undamaged laminates. Q3D results show that: (1) in-plane transverse tensile stresses exist in the +15° plies near the free edges of all of the laminates and (2) only the interlaminar shear stress is high at the + 15/? interface. Three-dimensional (3D) finite-element analyses are used to model a + 15° ply crack near the laminate free edge. The 3D analysis results indicate that large tensile interlaminar normal, as well as shear, stresses develop at the intersection of the matrix crack and the free edge. This suggests that the interlaminar normal stress plays a significant role in the failure of these laminates and emphasizes the importance of modeling matrix cracking in delamination analyses of composite structures.

Download or read book Composites Engineering Handbook written by P.K. Mallick and published by CRC Press. This book was released on 1997-03-19 with total page 1270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers information on the fundamental principles, processes, methods and procedures related to fibre-reinforced composites. The book presents a comparative view, and provides design properties of polymeric, metal, ceramic and cement matrix composites. It also gives current test methods, joining techniques and design methodologies.