Study on mechanical properties of wind turbine tower reinforced by ribbed interlayer

In order to avoid the economic loss caused by the demolition and reconstruction of old steel wind turbine towers and to meet the demand of new generating units for tower strength and stiffness, this paper proposes a laminated ribbed structure for strengthening old wind turbine towers based on the concept of hollow laminated steel pipe concrete. The four interlayer ribbed reinforced cylinder specimens were made of two steel cylinders, both round and concentric, with vertical stiffening ribs evenly arranged on the inner surface of the outer cylinder and the outer surface of the inner cylinder, and concrete was poured between the two cylinders. The number of cavities, concrete thickness and shear-to-span ratio were used as the test parameters to conduct compression-bending tests on five specimens. The test results show that: the damage phenomenon of the specimen is obvious, the material performance of each component is fully played, and the stiffening ribs can effectively alleviate the local bulging of the specimen; in terms of ultimate bearing capacity, the most influential is the shear-to-span ratio, the smaller the shear-to-span ratio, the larger the ultimate bearing capacity, increasing the concrete thickness and the number of cavities can effectively improve the ultimate bearing capacity; in terms of initial stiffness and ductility, the increase of the number of cavities will significantly improve the initial stiffness and ductility of the specimen. In terms of initial stiffness and ductility, increasing the number of cavities will significantly improve the initial stiffness and ductility of the specimen. The reinforcement effect of sandwich layer with ribbed structure on the tower structure is remarkable. The finite element analysis software ABAQUS was used to establish a model consistent with the test, and the calculation results were compared with the test results to verify the feasibility and accuracy of the established model and the material intrinsic structure relationship. On this basis, typical members are selected, and the stresses and plastic strains are combined with the longitudinal stresses and plastic strains to analyze the whole process of the stresses in the reinforced barrel of the sandwich ribbed structure in depth. The research results provide the theoretical basis and experimental basis for wind turbine tower reinforcement.