| China is walking on the way of ecological civilization construction.The modern wood structure has been widely concerned with the characteristics of Low-carbon environmental protection.The architecture of the modern wood structure has appeared on the scene,it also has launched a wave of modern wood structure research.Glued wood is the main role in modern wood structured,and the glued wood has the characteristics of high overall strength,defect dispersion,easy to machined into any size components.When unreinforced glulam beam was bent,the weak position of beam bottom once cracked,the crack develops rapidly and the entire component was destroyed,the strength of wood in the compression area of the glulam timber beam was not fully utilized.In order to improve the flexural rigidityand and bearing capacity of glulam beams,6 groups of 18 glued wood test beams were made by larch in northeast,and they were reinforced with new environmentally friendly material BFRP tendon.In this paper,experimental study and finite element simulations were conducted to investigate the flexural performance of glulam beam,and failure mode,stiffness and the ultimate load-carrying capacity of glulam beam were discussed under different reinforcement ratio.This paper mainly studied from the following aspects:(1)The material parameter of glulam wood and BFRP tendon are obtained through material property test,the material constitutive relationship was revealed,which provided the basis of the finite element analysis model parameter value for the subsequent theoretical calculation.(2)FEM software ABAQUS was used to establish the finite element model of reinforced glulam timber beam,the BFRP reinforcement ratio effect on the bearing capacity of glulam timber beam was studied,the load and deflection of each model were concluded,and the improvement of bearing capacity and rigidity of glulam timber beam under each reinforcement ratio were obtained.(3)One group of unreinforced glulam beams and five groups of reinforced glulam beams with different reinforcement ratio were subjected to bending test.The experimental phenomena and the failure forms in the test were described.Obtained the limit load,the span deflection,the load-deflection curve and the load-strain curve of each group specimen,and analyzed the influence of the BFRP tendon on the glulam beam bending.The test result was compared with the finite element analysis result and they were in good agreement.The results show that the failure patterns of BFRP reinforced glulam showed tensile brittle failure,drawing damage and compressive ductility destruction three kinds of failure forms.when the reinforcement ratio is not greater than 0.77%,the BFRP reinforced glulam timer beam is tensile brittle failure.When the reinforcement rate range is greater than 0.77%less than 1.51%,the test beam is drawing damaged.When the reinforcement ratio is not less than 1.51%,it is subjected to compressive ductility damage.The BFRP tendon could reduce the influence of defects on glulam beam bending,delayed the tensile damage of the wood fibers on the tensioned side and made the wood strength in the compressed area of the beam was fully utilized.The flexural ultimate bearing capacity and rigidity of the glulam beam were improved,and the deformation performance of the glulam beam was improved remarkably When the reinforcement ratio increased to over reinforced,the bearing capacity of the reinforced bar would not increase. |
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