PSI - Issue 5

Khodjet-Kesba Mohamed et al/ Structural Integrity Procedia 00 (2017) 000 – 000

8

Khodjet-Kesba Mohamed et al. / Procedia Structural Integrity 5 (2017) 271–278

278

0,32

i=1 (T=22°C ) i=2 (T=60°C ) i=3 (T=120°C )

0,28

0,24

0,20

0,16

 (x)/  c

0,12

0,08

0,04

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 0,00

X/l

Fig. 6. Hygrothermal effect on the interlaminar shear stress τ along the length of [0/90 3 ] s laminates with a=2.5 and Vf=0.7

5. Conclusion

A simple method has been proposed to predict the effect of transverse cracks on the stress distribution of the cross ply composite laminate. For an undamaged laminate, the various analytical models give the same stress distribution across the thickness and along the laminate. At high crack density, only a parabolic variation of longitudinal displacement in 0° and 90° layers give a good approximation of the stress distribution obtained by finite element analysis, which makes this method more useful for studying the transverse cracking multiplication and modeling the hygrothermal aging. In the second part of this study, the cracked cross-ply laminate is exposed to the moisture absorption submitted to transient and non-uniform moisture concentration distribution. It has been observed a large influence of temperature and moisture absorption effect on the reduction of the interlaminar shear stress along the laminate. This makes very attractive the study when we want to see the hygrothermal effect on the mechanical properties of composite laminates with intra- and interlaminar damage. Berthelot, J-M., Le Corre, J-F. 1999. Modelling the transverse cracking in cross-ply laminates: application to fatigue. Composites B 30. 569 – 577. Berthelot, J.M., 1997. Analysis of the transverse cracking of cross-laminates: a generalized approach. J. Compos. Mater. 31. 1780 – 1805. Boniface L. and Ogin S.L., 1989. Application of the Paris equation to the fatigue growth of transverse ply cracks. Journal of Composite Materials 23. 735-754 Chamis, C.C., 1983. Simplified composite micromechanics equations of hygral, thermal, and mechanical properties. SAMPE Quart 15. 14 – 23. Garret, K.W. and Bailey, J.E., 1977. Multiple transverse fracture in 90° cross-ply laminates of a glass fibre-reinforced polyester. J. Mater. Sci,12. 157-168. Hashin, Z., 1985. Analysis of cracked laminates: a variational approach. Mech. Mater. 4, 121 – 136. Khodjet-kesba M, AddaBedia EA, Ben khedda A, Boukert B., 2015. Hygrothermal effect in [θm/90n]s cracked composite laminates -desorption case. Pro. Eng. 114. 110-117. Khodjet- kesba M, AddaBedia EA, Benkhedda A, Boukert B., 2016. Prediction of Poisson’s ratio degradation in hygrothermal aged a nd cracked [θm/90n]s composite laminates. Ste.& Comp. Struc. 21. 57 -72. Khodjet-kesba M., AddaBedia E.A., Benkhedda A., Boukert B. and Rezoug, T., 2016. The influence of hygrothermal effects on the cross-ply composite laminate with transverse cracking in transient mode. Mech. And Indus. 18. 102-110 Lundgren J.E., Gudmundson R., 1999. Moisture absorption in glass-fibre/epoxy laminates with transverse matrix cracks. Comp. Scien. And Tech. 59. 1983-1991. Reifsnider, K.L., 1977. Some fundamental aspect of the fatigue and fracture response of composite materials. Processing of 14th annual society of engineering science meeting, Lehigh University, Bethlehem. 14-16. Rezoug, T., Benkhedda, A., Khodjet-Kesba, M., Adda bedia, E.A., 2011. Analysis of the composite patches cracked and aged in hygrothermal conditions, Mechanics and industry 12. 395-398. Talerja R., 1986. Stiffness properties of composite laminates with matrix cracking and interior delamination. Eng. Fract. Mech. 25.751 – 62. Varna J. and Berglund L.A., 1992. A model for prediction of the transverse cracking strain in cross-ply laminates. Journal of Reinforced Plastics and Composites 11. 708-728 References