Study On Compressive And Flexural Mechanical Properties Of FRP Bamboo-based Composite Material

As a new kind of environment-friendly material,bamboo-based composites have high strength and good mechanical properties,and have been paid more and more attention by experts and scholars in recent years.Fiber reinforced polymer(FRP)have the advantages of high strength,corrosion resistance,light weight and simple construction.The use of FRP bamboo-based composites can improve its bearing capacity and corrosion resistance.At present,the research on FRP bamboo-based composites at home and abroad is still in its infancy.In general,research on this is limited,and there is no unified theory.Therefore,it is of great significance to study the mechanical properties of FRP bamboo-based composites for their application in buildings.In this paper,based on the study of mechanical properties of materials,the flexural properties of AFRP parallel bamboo strand lumber beams were studied.Taking the distribution rate as a variable parameter,the changes of ultimate load,ultimate deflection,stiffness and ductility of parallel bamboo strand lumber beams under different distribution rates were discussed.The experimental results show that AFRP can enhance the compressive mechanical properties of parallel bamboo strand lumber.With the increase of distribution rate,the ultimate load,ultimate deflection,stiffness and ductility of bamboo recombinant beam are also enhanced.When the distribution rate is 0.57%,the ultimate bearing capacity,stiffness and ductility of the beam are maximized,the ultimate bearing capacity is 34.5% higher than that of the unconstrained bamboo recombinant material,the stiffness is increased by 15%,and the ductility is increased by 17%.Deducing the calculation formulas of ultimate bending moment of parallel bamboo strand lumber beams and AFRP parallel bamboo strand lumber beams.The flexural mechanical properties of FRP laminated bamboo lumber beams under low cyclic reversed loading were studied by taking the types of FRP,different bamboo arrangement forms and cloth distribution rate as variable parameters.The test results show that the type of FRP cloth has certain influence on the flexural properties of laminated bamboo lumber beams.The mechanical properties of laminated bamboo lumber beams reinforced by GFRP cloth are better,The reverse limit load of GFRP laminated bamboo lumber beam increased by 0.39%,the positive limit displacement increased by 0.057%,the reverse displacement increased by 0.22% and the ductility increased by 7.9% under Unit distribution rate and unit density.The flexural properties of V-section laminated bamboo lumber beams is stronger than that of Hsection laminated bamboo lumber beams.Based on Euler-Bernoulli beam theory,the ultimate deflection of laminated bamboo lumber beams with different FRP ratios under low cyclic reversed loading is deduced,the theoretical values are compared with the experimental values,and the comparison results are in good agreement.In this paper,the effect of slenderness ratio,distribution ratio and compression direction on the compressive properties of AFRP laminated bamboo lumber were studied by the compressive tests under axial monotonic loading.It is concluded that increasing the distribution rate can increase the ultimate load and restrain the ductility of laminated bamboo lumber.When the distribution ratio is 0.9%,the ductility and ultimate load of the specimens reach the maximum,the ultimate load was increased by 3.5% and the ductility was increased by 6%.The ultimate load of laminated bamboo lumber under parallel grain compression is much larger than that under radial or chord compression.The effects of slenderness ratio,distribution ratio and compression direction on the compressive properties of laminated bamboo lumber under low cyclic reversed loading was studied by the low cycle reversed axial compression test conducted on 18 laminated bamboo lumber and 34 AFRP laminated bamboo lumber.The results show that AFRP can indeed increase the compressive performance of laminated bamboo lumber under low cyclic reversed loading,and the compressive performance of laminated bamboo lumber with 0.9% distribution ratio is the strongest,the ultimate load increased by 3.7%.The ultimate bearing capacity of laminated bamboo lumber is indeed affected by slenderness ratio and compressive direction,the larger slenderness ratio,the smaller ultimate compressive capacity with the same other parameters.With the same distribution ratio and slenderness ratio,the compressive performance of laminated bamboo lumber under compression parallel to grain is stronger than that under radial and chord compression.The stress-strain relationship between the unloading curve and the reloading curve is deduced according to the test data,and in good agreement with the test results.At the end of this paper,the author summarizes the full text,and puts forward the prospect of the future development.