6. Conclusions
The bending and shear response of adhesively-bonded GFRPglass sandwich structures has been investigated and the following conclusions were drawn: 1. The feasibility of fabricating sandwich structures made of tempered glass thick face sheets adhesively-bonded to GFRP pultruded core profiles has been analytically, numerically and experimentally demonstrated. The proposed GFRP-glass sandwich concept offers potential for designing transparent, thin and structurally stiff building envelopes that outperforms existing non-composite envelope systems. 2. New analytical models for predicting the deflections and axial and shear strains of adhesively-bonded sandwich structures with shear-flexible adhesives and cores have been developed. The models have been validated by linear elastic numerical simulations and discrepancies between analytical and numerical predictions were only of around 11% (deflections) and 18% (axial and shear strains) for a span-to-depth ratio of 7 and reduced rapidly for larger ratios. 3. The analytical prediction of deflections has also been validated experimentally: analytical prediction underestimated experimental results by only 11%. However analytical prediction of mid-span axial strain (on lower face sheet) overestimated the experimental result by 48%. In contrast to deflections, axial strains appear to be very sensitive to the bending of face sheets about their own local axes. Further investigation of the strain distribution in sandwich structures is therefore required. 4. A composite action of 95% (in terms of deflections) can be obtained in the proposed GFRP-glass sandwich beams bonded with moderately stiff adhesives (Gadh = 49E3 GPa) for a spanto-depth ratio of 12. This percentage of composite action is significantly higher than that provided by low shear modulus adhesives (Gadh = 0.5E3 GPa), e.g. structural silicones, which has been predicted to be of 16%.
