海上风机钢管约束UHPC-钢灌浆连接段轴压性能研究OA

Ultra-high-performance-concrete(UHPC)is an effective way to improve the mechanical and economic performance of support structures for offshore wind turbines(OWTs)due to its ultra-high compressive performance,excellent tensile,fatigue and corrosion resistance.In order to further promote the application of UHPC in OWTs,a novel type of tubed UHPC sleeve to steel tube grouted connection is proposed in this work.By welding shear keys on the outer surface of the steel tube,and setting steel tube inside and annular trapezoidal shear keys on the surface of UHPC sleeve,the steel corrosion can not only be prevented,but also the transverse deformation of the grout connection can be effectively restrained,and the compressive strength of grout and UHPC is enhanced,so as to improve the integrity,stiffness,strength and ductility.This novel grouted connection can be used in monopile,jacket,and floating structures.In order to study the axial compression performance of the novel tubed UHPC sleeve to steel tube grouted connection connection,the finite element software ABAQUS is adopted.The material nonlinearity and geometric nonlinearity as well as the tensile strain hardening performance of the UHPC material are considered in the model.The load-displacement curves and failure modes obtained by the simulation agree well with the typical test results.The mechanism and parameter analysis of the axial compression performance of the connection are carried out by using the verified finite element model.The results show that the failure process of the novel grouted connection can be divided into linear elastic stage,micro-crack development stage,compression strut force transferring stage and failure stage.The diameter to thickness ratio of the steel tube has the most significant influence on the performance of the connection.The novel grouted connection behaved the basically similar to the traditional steel-steel grouted connection,and is anticipated to be widely used in engineering practice.