| The glued laminated bamboo is a new building material with development potential which is made of bamboo by industrial processes. Not only in the physical performance is it superior to the traditional wood, but also better than the concrete, masonry and other traditional building materials in the green environmental protection. At present, the study of glued laminated bamboo is still not mature enough, for most of research focuses on basic mechanical properties of materials and components, such as axial compression performance, bending performance. But, there is almost no research on eccentric compression performance of glued laminated bamboo column. In the actual engineering structure, there rarely have ideal axial compression members. Even designed according to axial compression, they are also under additional bending moment due to accidental transverse load, not ideal bearing conditions, or construction deviation and so on. Therefore, it is very meaningful to research the eccentric compression capacity of glued laminated bamboo.Firstly, the axial tensile and compressive performance of material is study through material experiment. The results show that the tensile strength of glued laminated bamboo is 119.19 MPa, modulus of elasticity is 10.02GPa, the compressive strength is 51.41 MPa, modulus of elasticity is 8.71 GPa, the proportional limit is 34.43 MPa. Axial tensile failure is brittle fracture and stress-strain showed a linear relationship. Axial compression failure is plastic failure, initially stress-strain is a linear relationship, then a nonlinear relationship. Axial compression stress-strain curve can be divided into two stages:elastic stage of small deformation and large deformation in plastic stage. This paper set up mathematical model about axial tension and compression stress-strain of glued laminated bamboo based on this phenomenon by using piecewise function. In tension and ratio of compressive stage adopts linear, pressurized plastic section uses the quadratic parabola, and it is in good agreement with the test results.Secondly, three different slenderness ratio of glued laminated bamboo specimens are designed by referring to the wood test method standard to study its bearing capacity under the different initial eccentricity. The results of the analysis show that when initial eccentricity is a certain, bearing capacity reduce and deformation increase gradually with the increase of slenderness ratio and when slenderness ratio is a certain, bearing capacity decreases and the deformation and the second moment increase gradually with the increase of initial eccentricity. Three different slenderness specimens will eventually damage appearing similar to the bending due to big lateral displacement under eccentric load, and damage is in the tension side. But, in the whole deformation process, the specimen cross section always maintain level which accord with flat section assumption, and the deformation curve of the specimens are in good agreement with those obtained with quadratic polynomial function.Finally, the bearing force of glued laminated bamboo is analysis based on theory. According to the different modulus theory, deflection curve of glued laminated bamboo accords with quadratic polynomial function when it is destroyed. According to the experimental phenomena, tensile or compressive edge meets the limit strain as the failure criterion to damage, puts forward two kinds of analysis model, and lateral deflection is corrected under small bias, calculate different slenderness equivalent axial force and bending moment of the ends of the specimen ratio. Compared with the theoretical value through the testing value, it shows good agreement. |
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