C Dong I Davies/ Materials and Design 54(2014) 893-899 Flexural --0--Tcnsilc --Tensile 70 100 40 30 0.2 0.4 0.8 0.0 0.6 0.8 1.0 Hybrid ratio Fig. 11. Flexural modulus at S/h=64 and tensile modulus versus hybrid ratio for Fig. 13. Flexural modulus at s/h= 64 and tensile modulus versus hybrid ratio when Ve=30% and Vix=70%. =50% and vix=50% 120 Flexural l00 -- Tensile 四E2 80 0.2 1.0 Hybrid ratio Vg. 52 aex val mogulus at s/h=b4 and tensile modulus versus hybrid ratio for Hybrid ratio Fig. 14. Flexural modulus at S/h=64 and tensile modulus versus hybrid ratio for Va=50% and V=70%. 3. Results and discussion Flexural 3. 1. Comparison of FEA and CLt -.-C--Tensile The flexural moduli at S/h=64 when Vfe=50% and Vig=50% from the FEa and CLt are shown in Fig. 7. It is seen that in general 140 the results from the FEa and clt are in good agreement. 3. 2. Effects of span-to-depth ratio When both Vig=50% and Vfe-50%, the effect of span-to-depth ratio on flexural modulus is shown in Fig 8. It is shown that ural modulus increases when the span-to-depth ratio increa from 16 to 32 and becomes stable with further increase of th ratio 3.3. Effects of fibre volume fractions Hybrid ratio The flexural moduli at a span to depth ratio of 64 and the tensile Fig 15. Flexural modulus at S/h =64 and tensile modulus versus hybrid ratio for moduli are plotted versus the hybrid ratio is shown in Figs. 9-17 Ve=70% and Vx-30%. for the nine fibre volume fraction combinations In contrary to the previous studies [11, hybrid effects exist for e side start placed by glass epoxy flexural modulus. It is shown from the full carbon/epoxy laminate, lam s on the hybrid effe As more glass/epoxy flexural modulus decreases rapidly when the carbon/epoxy lami- laminas becomes stable. and3. Results and discussion 3.1. Comparison of FEA and CLT The flexural moduli at S/h = 64 when Vfc = 50% and Vfg = 50% from the FEA and CLT are shown in Fig. 7. It is seen that in general the results from the FEA and CLT are in good agreement. 3.2. Effects of span-to-depth ratio When both Vfg = 50% and Vfc = 50%, the effect of span-to-depth ratio on flexural modulus is shown in Fig. 8. It is shown that flexural modulus increases when the span-to-depth ratio increases from 16 to 32 and becomes stable with further increase of the span-to-depth ratio. 3.3. Effects of fibre volume fractions The flexural moduli at a span to depth ratio of 64 and the tensile moduli are plotted versus the hybrid ratio is shown in Figs. 9–17 for the nine fibre volume fraction combinations. In contrary to the previous studies [11], hybrid effects exist for flexural modulus. It is shown from the full carbon/epoxy laminate, flexural modulus decreases rapidly when the carbon/epoxy laminas on the compressive side start to be replaced by glass/epoxy laminas and negative hybrid effects occur. As more glass/epoxy laminas are introduced, flexural modulus becomes stable, and Fig. 11. Flexural modulus at S/h = 64 and tensile modulus versus hybrid ratio for Vfc = 30% and Vfg = 70%. Fig. 12. Flexural modulus at S/h = 64 and tensile modulus versus hybrid ratio for Vfc = 50% and Vfg = 30%. Fig. 13. Flexural modulus at S/h = 64 and tensile modulus versus hybrid ratio when Vfc = 50% and Vfg = 50%. Fig. 15. Flexural modulus at S/h = 64 and tensile modulus versus hybrid ratio for Vfc = 70% and Vfg = 30%. Fig. 14. Flexural modulus at S/h = 64 and tensile modulus versus hybrid ratio for Vfc = 50% and Vfg = 70%. C. Dong, I.J. Davies / Materials and Design 54 (2014) 893–899 897