Öz In the present study, the effects of hot water ageing on the glass fiber reinforced epoxy woven composites were experimentally examined. The specimens in three groups which undamaged, damaged, and single patch-repaired ones were kept in tap water at 50°C and 70°C temperature for 8 days and 16 days. At the end of those periods, the moisture absorption rates were calculated, the maximum failure loads at the end of period of keeping in hot water were determined and the failure modes occurring on these specimens were observed and compared. As a result of experimental study, it was found that the moisture absorption rates increased but the failure load values decreased together with the increase in water temperature and duration of hot water ageing.
 Campilho, R.D.S.G., Moura, M.F.S.F., Domingues, J.J.M.S., Numerical prediction on the tensile residual strength of repaired CFRP under different geometric changes, International Journal of Adhesion & Adhesives, 29 (2009) 195– 205. Campilho, R.D.S.G., Mmnoura, M.F.S.F., Domingues, J.J.M.S, Modelling single and double-lap repairs on composite materials, Composites Science and Technology, 65 (2005) 1948–1958. Toudeshky, H. H., Mohammadi, B., Mixed-mode numerical and experimental fatigue crack growth analyses of thick aluminium panels repaired with composite patches, Composite Structures, 91 (2009) 1–8. Toudeshky, H. H., Mohammadi, B., Daghyani, H. R., Mixed-mode fracture analysis of aluminium repaired panels using composite patches, Composites Science and Technology, 66 (2006) 188–198.  Toudeshky, H.H., Effects of Composite Patches on Fatigue Crack Propagation of Single-side Repaired Aluminum Panels, Composite Structures ,76 (2006), 243–251.  Oudad, W., Bouiadjra, B. B., Belhouari, M., Touzain, S. , Feaugas, X. , Analysis of the plastic zone size ahead of repaired cracks with bonded composite patch of metallic aircraft structures, Computational Materials Science, 46 (2009) 950–954. Ouinas, D., Bouiadjra, B.B.,Serier, B., Bekkouche, M. S., Comparison of the effectiveness of boron/epoxy and graphite/epoxy patches for repaired cracks emanating from a semicircular notch edge, Composite Structures, 80 (2007) 514–522.  Ouinas, D., Sahnoune, M., Bebderdouche, N., Bouiadjdjra, B.B., Stress İntensity Factor Analysis for Notched Cracked Structure Repaired by Composite Patching, Materials and Design, 30 (2009), 2302–2308.  Bouiadjra, B. B., Belhouari, M., Serier, B., Computation of the stress intensity factors for repaired cracks with bonded composite patch in mode I and mixed mode, Composite Structures , 56 (2002) 401–406.  Bouiadjra, B.B., Rezgani, L., Ouinas, D., Belhouari, M. , Ziadi, A., Numerical Analysis of the Notch effect and the Behaviour of Notch Crack in Adhesively Bonded Composite Laminates, Computational Materials Science. 38 (2007), 759–764.  Papanikos, P., Tserpes, K.I., Pantelakis, Sp., Initiation and progression of composite patch debonding in adhesively repaired cracked metallic sheets, Composite Structures, 81 (2007) 303–311.  Umamaheswar, T.V.R.S., Singh, R., Modelling of a patch repair to a thin cracked sheet, Engineering Fracture Mechanics , 62 (1999), 267-289.  Charalambides, M.N., Hardouin, R., Kinloch, A.J., Mathews, F.L., Adhesively-bonded Repairs to Fibre-composite Materials I: Experimental, Composites Part A, 29A (1998), 1371-1381.  Achour, T., Bouiadjra S. B., Numerical Analysis of the Performances of the Bonded Composite Patch for Reducing Stress Concentration and Repairing Cracks at Notch, Computational Materials Science, 28 (2003), 41–48.  Tsouvalis N.G., Mirisiotis, L.S.N, Experimental Investigation of the Static Behaviour of a Hole Drilled Steel Plate Reinforced with a Composite Patch, Strain, (2008) 44, 133–140.  Her, S.C., Chao, M., Adhesively Bonded Patch Repair of Composite Laminates , Journal of Adhesion Science and Technology, 25 (2011), 2569–2585.  Madani, K., Touzain, S., Feaugas, X., Benguediab, M., Ratwani, M., Numerical analysis for the determination of the stress intensity factors and crack opening displacements in plates repaired with single and double composite patches, Computational Materials Science, 42 (2008), 385–393.  Ridha, M., Tan, V.B.C., Tay, T.E., Traction–separation laws for progressive failure of bonded scarf repair of composite panel, Composite Structures, 93 (2011), 1239–1245.  Liu, X., Wang, G., Progressive failure analysis of bonded composite repairs, Composite Structures, 81 (2007), 331-340.  Turan, K., Örçen, G., Failure analysis of adhesive-patch repaired edge-notched composite plates, The Journaal of Adhesion, 93:(4), (2017), 328-341.  Park, Y.B., Song, M.G., Kim, J.J., Kweon, J.H., Choi, J.H., Strength of carbon/epoxy composite single-lap bonded joints in various environmental conditions, Composite Structures, 92 (9) ,(2010), 2173–2180.  Walker, S.P., Thermal effect on the compressive behavior of IM7/PET15 laminates, J Compos Mater, 38 (2004), 149–162. Bismarck, A., Hofmeier, M., Dörner, G., Effect of hot water immersion on the performance of carbon reinforced unidirectional poly(ether ether ketone) (PEEK) composites: stress rupture under end-loaded bending, Composites Part A, 38 (2007), 407–426. Parker, B.M., Some effects of moisture on adhesive-bonded CFRP–CFRP joints, Composite Structures, 6 (1986), 123–139. Ashcroft, I.A. , Hughes, D.J. , Shaw, S.J. , Adhesive bonding of fiber reinforced polymer composite materials, Assembly Autom, 20 (2000), 150–161. Akderya , T. , Kemiklioglu , U., Sayman , O., Effects of thermal ageing and impact loading on tensile properties of adhesively bonded fibre/epoxy composite joints, Composites Part B, 95 (2016), 117-122. Soykok, I.F., Degradation of single lap adhesively bonded composite joints due to hot water ageing, The Journal of Adhesion, http://dx.doi.org/10.1080/00218464.2015.1076340. Zhang, F. , Wang, H.P., Hicks, C. , Yang, X. , Carlson, B. E., Zhou, Q. , Experimental study of initial strengths and hygrothermal degradation of adhesive joints between thin aluminum and steel substrates, International Journal of Adhesion & Adhesives, 43 (2013), 14–25. ASTM Standart D5868-01.1995, Standart Test Method for Lap Shear Adhesion for Fiber Reinforced Plastic (FRP) Bonding, ASTM International, West Conshohocken,PA,2014,DOI: 10.1520/D5868-01R14,www.astm.org.  Assarar, M., Scida, D., El Mahi , A., Poilâne , C. , Ayad, R., Influence of water ageing on mechanical properties and damage events of two reinforced composite materials: Flax–fibres and glass–fibres, Materials and Design, 32 (2011) ,788–795.