دانلود رایگان مقاله اجزای ساندویچی GFRP شیشه ای باندشونده برنامه پوشش شیشه ای ساختاری کارآمد

abstract

Composite sandwich structures made of thick glass face sheets adhesively-bonded to glass fibrereinforced polymer (GFRP) core profiles have the potential to outperform existing non-composite glazing configurations but their feasibility has yet to be investigated and there are no analytical models that describe their structural response. This paper presents the new analytical models for predicting deflections and strains in adhesively-bonded GFRP-glass sandwich beams. The new analytical models successfully account for: the shear deformations of the core and adhesive layers; the local bending of the constituent parts about their centroidal axes; and the global bending of the sandwich component as a whole. The deflections and strains predicted by analytical models are validated by finite element simulations and compared with the results of destructive tests performed on adhesively-bonded GFRP-glass beams in a four-point bending configuration. The analytical models were also evaluated for alternative GFRP-glass configurations tested by others. The GFRP-glass beams specially assembled in this study con- firm the physical feasibility of constructing these proposed components.

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 = 49E
3 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 = 0.5E
3 GPa), e.g. structural silicones, which has been predicted to be of 16%.