Interfacial Fracture Toughness of Unconventional Specimens: Some Key Issues

• Autorzy: Tsokanas Panayiotis , Fisicaro Paolo , Loutas Theodoros , Valvo Paolo Sebastiano

Identyfikatory

DOI

10.35784/jteme.3361

• Języki publikacji: EN

Abstrakty

EN

Laboratory specimens used to assess the interfacial fracture toughness of layered materials can be classified as either conventional or unconventional. We call conventional a specimen cut from a unidirectional composite laminate or an adhesive joint between two identical adherents. Assessing fracture toughness using conventional specimens is a common practice guided by international test standards. In contrast, we term unconventional a specimen resulting from, for instance, bimaterial joints, fiber metal laminates, or laminates with an elastically coupled behavior or residual stresses. This paper deals with unconventional specimens and highlights the key issues in determining their interfacial fracture toughness(es) based on fracture tests. Firstly, the mode decoupling and mode partitioning approaches are briefly discussed as tools to extract the pure-mode fracture toughnesses of an unconventional specimen that experiences mixed-mode fracture during testing. Next, we elaborate on the effects of bending-extension coupling and residual thermal stresses often appearing in unconventional specimens by reviewing major mechanical models that consider those effects. Lastly, the paper reviews two of our previous analytical models that surpass the state-of-the-art in that they consider the effects of bending-extension coupling and residual thermal stresses while they also offer mode partitioning.

Słowa kluczowe

EN

residual thermal stresses; analytical modeling; interlaminar cracking; non-standard specimen; laminated material; bending-extension couplin

• Wydawca: Polskie Towarzystwo Promocji Wiedzy ; Wydawnictwo Politechniki Lubelskiej
• Czasopismo: Journal of Technology and Exploitation in Mechanical Engineering
• Rocznik: 2023
• Tom: Vol. 9, nr 1
• Strony: 1--10
• Opis fizyczny: Bibliogr. 21 poz., fig.

Twórcy

autor

Tsokanas Panayiotis

• Department of Mechanical Engineering and Aeronautics, University of Patras, Patras University Campus, GR-26504, Patras, Greece (Greece)

• https://orcid.org/0000-0001-5110-0632

autor

Fisicaro Paolo

• University of Pisa, Department of Civil and Industrial Engineering, Largo Lucio Lazzarino 1, I-56122 Pisa, Italy (Italy)

• https://orcid.org/0000-0002-9931-6149

autor

Loutas Theodoros

• University of Patras, Department of Mechanical Engineering and Aeronautics, Patras University Campus, GR-26504 Patras, Greece (Greece)

• https://orcid.org/0000-0002-4092-6225

autor

Valvo Paolo Sebastiano

• University of Pisa, Department of Civil and Industrial Engineering, Largo Lucio Lazzarino 1, I-56122 Pisa, Italy (Italy)

• https://orcid.org/0000-0001-6439-1926

Bibliografia

• [1]Standard Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites,ASTM D5528-13, ASTM International, 2013.
• [2]P. Manikandan and C. B. Chai, “Mode-I metal-composite interface fracture testing for fibre metal laminates,” Adv. Mater. Sci. Eng., vol. 2018, art. no. 4572989, 2018.
• [3]K. Dadej, J. Bieniaś, and P. S. Valvo, “Experimental testing and analytical modeling of asymmetric end-notched flexure tests on glass-fiber metal laminates,” Metals, vol. 10, no. 1, art. no. 56, 2020.
• [4]J. Rzeczkowski, S. Samborski, and P. S. Valvo, “Effect of stiffness matrices terms on delamination front shape in laminates with elastic couplings,” Compos. Struct., vol. 233, art. no. 111547, 2020.
• [5]V. Saseendran, C. Berggreen, and L. A. Carlsson, “Fracture mechanics analysis of reinforced DCB sandwich debond specimen loaded by moments,” AIAA J., vol. 56, no. 1, pp. 413–422, 2018.
• [6]J. R. Reeder, K. Demarco, and K. S. Whitley, “The use of doubler reinforcement in delamination toughness testing,” Compos. Part A Appl. Sci., vol. 35, no. 11, pp. 1337–1344, 2004.
• [7]P. Tsokanas, T. Loutas, G. Kotsinis, V. Kostopoulos, W. M. van den Brink, and F. Martin de la Escalera, “On the fracture toughness of metal-composite adhesive joints with bending-extension coupling and residual thermal stresses effect,” Compos. B. Eng., vol. 185, art. no. 107694, 2020.
• [8]C. Alía, J. M. Arenas, J. C. Suárez, R. Ocaña, and J. J. Narbón, “Mode II fracture energy in the adhesive bonding of dissimilar substrates: carbon fibre composite to aluminium joints,” J. Adhes. Sci. Technol., vol. 27, no. 22, pp. 2480–2494, 2013.
• [9]Z. Ouyang, G. Ji, and G. Li, “On approximately realizing and characterizing pure mode-I interface fracture between bonded dissimilar materials,” J. Appl. Mech.,vol. 78, no. 3, art. no. 031020, 2011.
• [10]T. Garulli, A. Catapano, D. Fanteria, J. Jumel, and E. Martin, “Design and finite element assessment of fully uncoupled multi-directional layups for delamination tests,” J. Compos. Mater.,vol. 54, no. 6, pp. 773–790, 2020.
• [11]P. Tsokanas and T. Loutas, “Fracture mode partitioning: a literature review.”(to be submitted)
• [12]J. N. Reddy, Mechanics of Laminated Composite Plates and Shells: Theory and Analysis, 2nd ed. Boca Raton, FL: CRC Press, 2003.
• [13]P. S. Valvo, “On the calculation of energy release rate and mode mixity in delaminated laminated beams,”Eng. Fract. Mech., vol. 165, pp. 114–139, 2016.
• [14]P. Tsokanas and T. Loutas, “Hygrothermal effect on the strain energy release rates and mode mixity of asymmetric delaminations in generally layered beams,”Eng. Fract. Mech., vol. 214, pp. 390–409, 2019.
• [15]S. Bennati, P. Fisicaro, L. Taglialegne, and P. S. Valvo, “An elastic interface model for the delamination of bending-extension coupled laminates,” Appl. Sci., vol. 9, no. 17, art. no. 3560, 2019.
• [16]J. A. Nairn. “On the calculation of energy release rates for cracked laminates with residual stresses,”Int. J. Fract.,vol. 139, no. 2, pp. 267–293, 2006.
• [17]T. Yokozeki, T. Ogasawara, and T. Aoki, “Correction method for evaluation of interfacial fracture toughness of DCB, ENF and MMB specimens with residual thermal stresses,” Compos. Sci. Technol., vol. 68, no. 3–4, pp. 760–767, 2008.
• [18]T. Yokozeki, “Energy release rates of bi-material interface crack including residual thermal stresses: application of crack tip element method,”Eng. Fract. Mech., vol. 77, no. 1, pp. 84–93, 2010.
• [19]J. Wang and P. Qiao, “Interface crack between two shear deformable elastic layers,” J. Mech. Phys. Solids, vol. 52, no. 4, pp. 891–905, 2004.
• [20]P. Tsokanas and T. Loutas, “Closed-form solution for interfacially cracked layered beams with bending-extension coupling and hygrothermal stresses,” Eur. J. Mech. A Solids, vol. 96, art. no. 104658, 2022.
• [21]P. Tsokanas, T. Loutas, and A. P. Vassilopoulos, “Fracture toughness of elastically coupled laminates: evaluation of analytical solutions through digital image correlation,” inProc. 20thEur.Conf. Compos.Mater.(ECCM20), 2022, pp. 812–819.