Research On Structure And Mechanical Property Of The Family Palame And Boinic Design Of Wind Turbine

Natural plants keep evoluting and choicing during a long competition for survival, forsome specific function, the macroscopic and microscopic structure of the plant system havealmost reached the best design, which is incomparable to artificial design. Roystonea of palmplants is always living in the coastal wind zone, and its flexible multi-body system reflect theexcellent wind-resisted characteristic. Wind turbine and Roystonea are similar in structureconfiguration and stress environment, the study on macroscopic and microscopic structuremechanical properties of Roystonea will can provide new aspiration for the flexible design oflarge-scale wind turbine.Based on finite element theory and numerical simulation, the static and dynamiccharacteristics of plant vein, petiole, stem and stem-sheath-petiole multi-body system werestudied, by comparison, we found that conical vein structure has relatively greater flexibility,the maximum stress is not concentrated on the root of vein, and it’s more conducive to realizeunload and avoid load concentration of lateral veins and main veins, conical vein structureimprove the adaptive ability of leaf under wind load. Cross section of sandwich structuremake trunk own excellent specific strength and specific rigidity, the sandwich structure isvery suitable for lightweight design. The variable cross section shape on axial enhances theflexibility of the trunk and reduces the stress load on tree root, besides, the trunk is very easyto produce coupling deformation, and it could reduce greatly environment load influence onother tissue. Large length-diameter ratio and anisotropic material properties make sure thatpetiole became a mixture of flexible and rigid. Elastic modulus of sheath exist a best value forstem-sheath-petiole multi-body system.Under constant relative density, material correlation model between petiole vascularbundle wall and macroscopic mechanical properties was constructed by replacing the poprousstructure of vascular bundle with equilateral triangle, square and hexagonal structure.Cross-sectional tensile, axial compression and bending properties of the equivalent wasanalysized by numerical simulation method to compare with vascular porous bundle model,the result shows that material correlation model is feasible, and hexagonal structure is moreclose to petiole vascular bundle structure. Based on material correlation mode, the completematerial properties could be gained by testing vascular axial modulus. The methods of cavityunit divided or merged was proposed for material layered design of hollow shaft and platestructure, and material property trend of different layeres was discussed.In view of Roystonea excellent mechanical properties in the aspects of macroscopic and microscopic structure, the flexible bionic structure design for large-scale wind turbine wasdiscussed, some new design ideas was proposed, such as three-bifurcation stiffener used totower, iso-stress tower with curve shape, blade root structure imitating trunk shape and so on,and the comprehensive performance of new tower and blade were better than the traditionalstructure. The stiffness distribution of wind turbine multibody system was explored simply tounderstand component stiffness influence on static and dynamic performance of blade-huband tower-nacelle-blade system.Studying the effects of relative moisture content on petiole MOE by tensile test, the datapost-processing show that power-law relationship is more suitable to describe the relationshipbetween MOE and relative moisture factor.