Bending performance of bamboo-laminated LVL composite beam
LIU Hong;YANG Lei;Taiyuan Heavy Industry Co.Ltd.;College of Civil Engineering,Nanjing Forestry University;
Laminated veneer lumber(LVL) is a wood-based composite with stable mechanical properties. Compared with the traditional solid lumber,the LVL is able to sufficiently utilize the wood resource. The laminated bamboo(LB) is a bamboo composite material made by a series of processing technologies. The mechanical properties of bamboo are better than those of wood. The laminated bamboo veneers pasted on upper and bottom sides of the LVL beams may fully utilize the compressive performances of this material and increase the load-carrying capacity of the component. Since the compressive constitutive lawof the LVL owns obvious nonlinearity,and the analysis for the ultimate load-bearing capacity of the LB panel reinforced the LVL beams needs to adopt the nonlinear model. The flexural performance of the LVL beams reinforced with the LB panel was investigated in this study. Mechanical performances and failure mode of the LVL bending members with and without the LB reinforcement were studied using four-point bending experiments. The test results showed that the load-carrying capacity of the LVL beams could be obviously improved due to the LB reinforcement. The comparison was conducted by analyzing the ultimate bearing capacity about the LVL bending members with and without the LB panel pasted on the lower surface. By taking into consideration of the nonlinear constitutive relation of the LVL composite,an analytical model was developed to estimate the flexural performances of LB-reinforced LVL beams. The experimental results verified the validity of the developed model. The load-bearing capacities of the LB panel-reinforced LVL beams increased by about 10%-50% when compared with the unreinforced components. The effect of the shear span ratio on the flexural specimen was studied. As the shear span ratio was relatively lower,the shear failure was not observed. The LVL has a long nonlinear segment along the grain compression,and the tension along the straight line always develops linearly,which makes the LVL with obvious nonlinearity. The error of bearing capacity tested and calculated value of flexural members was basically around 10%.The calculated value of the bearing capacity of the single plate laminated timber was in good agreement with the test values,which proved the feasibility of the calculation model of the bearing capacity.
【CateGory Index】： TS653.2
【CateGory Index】： TS653.2