PSI - Issue 14

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com Procedia Structural Integrity 14 (2019) 907–914

www.elsevier.com/locate/procedia

www.elsevier.com/locate/procedia

2 nd International Conference on Structural Integrity and Exhibition 2018 A Comparative Study of the Behavior of CFRP and GFRP Laminates in a Plate Specimen Using Modified Virtual Crack Closure Technique (MVCCT) Shubha Javagal a* , Raju J. b , Katta Venkataramana a a Department of Civil Engineering, National Institute of Technology Karnataka, Surathkal, 573201, India b Principal Scientist, STTD, CSIR- National Aerospace Laboratories, Bangalore 560008, India. 2 nd International Conference on Structural Integrity and Exhibition 2018 A Comparative Study of the Beh vior of CFRP a d GFRP Laminates in a Plate Specimen Using Modified Virtual Crack Closure Technique (MVCCT) Shubha Javagal a* , Raju J. b , Katta Venkataramana a a Department of Civil Engineering, National Institute of Technology Karnataka, Surathkal, 573201, India b Principal Scientist, STTD, CSIR- National Aerospace Laboratories, Bangalore 560008, India. The applications of polymer composites in aircraft industry have exponentially increased in the recent years due to their high strength to weight ratio. Presence of delaminations in composites is inevitable which affects the structural stability due to reduction in structural stiffness and strength. The degradation of a structural component depends on the geometric characteristics of delam n , nature of loading and material characteristics. Damage tolerance study is thus ss ntial to determine extent of de radation of he structure du t th presence of dela ination. The present paper brings about a comparision be ween the b hav ur of a s andard plate specim made up of C rbon Fibre Reinforced Polymer (CFRP) and Glass Fibre Reinforced Polymer (GFRP) l minates with circular delaminations of varying diam ters and subject to compre sive load. A constan compressive load in terms of initial displace en s was ap lied on a quasi-i otropic square plate sp cime of dimensions 200 mm x 200 mm with a thickn ss of 2.88 mm of oth CFRP an GFRP configuratio s. A circular delamination was int oduced at the centre of the plate and ts diameter and position along the thi kness dir ction were varied and studied. Using ABAQUS codes of pr ct ce, Strain Energy Release Rat (SERR) was computed. The princi les of Modified Virtual Crack Closure Technique (MVCCT) was used to compute SERR. Delamination propagates whe the computed mixed mode e ergy release ate exceeds the critical value, G C . Depending on the external l ading and material properties, Total str in energy release rate, G T (G T =G I +G II +G III ) w s used to predict growth of delamination. The onset of delaminat on growth was determined by pl tting th values of (G T /G C ) acro s various delamination sizes along the thickness of the plate and re or . © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. Abstract The applications of polymer composites in aircraft industry have exponentially increased in the recent years due to their high strength to weight ratio. Presence of delaminations in composites is inevitable which affects the structural stability due to reduction in structural stiffness and strength. The degradation of a structural component depends on the geometric characteristics of delamination, nature of loading and material characteristics. Damage tolerance study is thus essential to determine the extent of degradation of the structure due to the presence of delamination. The present paper brings about a comparision between the behaviour of a standard plate specimen made up of Carbon Fibre Reinforced Polymer (CFRP) and Glass Fibre Reinforced Polymer (GFRP) laminates with circular delaminations of varying diameters and subject to compressive load. A constant compressive load in terms of initial displacements was applied on a quasi-isotropic square plate specimen of dimensions 200 mm x 200 mm with a thickness of 2.88 mm of both CFRP and GFRP configurations. A circular delamination was introduced at the centre of the plate and its diameter and position along the thickness direction were varied and studied. Using ABAQUS codes of practice, Strain Energy Release Rate (SERR) was computed. The principles of Modified Virtual Crack Closure Technique (MVCCT) was used to compute SERR. Delamination propagates when the computed mixed mode energy release rate exceeds the critical value, G C . Depending on the external loading and material properties, Total strain energy release rate, G T (G T =G I +G II +G III ) was used to predict growth of delamination. The onset of delamination growth was determined by plotting the values of (G T /G C ) across various delamination sizes along the thickness of the plate and reported. Keywords: Virtual Crack Closure Technique, Strain Energy Release R te, CFRP, GFRP, Delamination. Abstract

Keywords: Virtual Crack Closure Technique, Strain Energy Release Rate, CFRP, GFRP, Delamination.

*Corresponding author. Tel.: +91-8105176460 E-mail address: shubha.javagal@gmail.com *Corresponding author. Tel.: +91-8105176460 E-mail address: shubha.javagal@gmail.com

2452-3216  2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 10.1016/j.prostr.2019.07.070 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers. 2452-3216 © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of Peer-review under responsibility of the SICE 2018 organizers.