Bonding Properties And Design Of Wind Turbine Blade Spar Based On Bamboo-poplar Laminates

The bonding strength is one of the most important properties of wood-based panels. Theobjective of this thesis is to investigate bonding strength of bamboo-poplar laminates by tensileshear and short-beam shear method. The factors having infuluence on the bonding strength ofbamboo-poplar laminates embrace shear and surface propertites of bamboo and woodrespectively, performance and content of rasin, temprature and time of processing pressure, andso forth. The materials about bamboo and wood are porous that can be compressible, so we cancontrol their density by putting changeable pressure on them.Here, a method of short-beam and tensile shear is presented to measure the bondingstrength of bamboo-poplar laminates at different density level, which made from theprocessing that contain a plasma surface treatment, vertical dipping, wood and bamboo group,and cold-pressing and heat-curing. This thesis also carry out design of wind turbine blade sparbased on bamboo-poplar laminates according to current design data. We should make aninterpolation and fitting of original data and then write program to divide spar into singlecomponent by VBA software in Excel eventually to manage the design, which can make acorrect direction to guide the use of bamboo-poplar laminates in the field of wind turbineblade.The main conclusions of this study are summarized as follows:(1) The bonding strength of bamboo-poplar laminates increases with the density, when thedensity is small, it performs a poor stability, as the density increases, its properties is up tostabilization. When its density is of0.95g/cm3, the shear strength reachs to the maximum andthe bamboo comes to shear failure.(2) Shear failure surface of bamboo made by SEM can be summerized into four typicaltypes of vertical strip between cells, longitudinal tear of a single cell, horizontal tear of a singlecell, horizontal strip between cell, respectively. (3) Boiled in water, the bonding strength of bamboo-poplar laminates decreasesignificantly, but when its density is of0.95g/cm3, the wood failure ratio is up to100%and thebamboo fails.(4) The shear strength of bamboo is the limit of which we design for the bamboo-poplarlaminates.(5) We should make an interpolation and fitting of original data and then write program todivide spar into single component by VBA software in Excel eventually to manage the design,which can make a correct direction to guide the use of bamboo-poplar laminates in the field ofwind turbine blade.