| The research shows that when the height is more than 100 meters,the wind fluctuation is less and the power generation quality is better.When the height of the traditional conical single-pipe tower barrel reaches more than 100 meters,the development of wind power generation industry is seriously restricted due to its large amount of steel,difficulty in processing and transportation,poor economy and low structural reliability.The research team's previous research on the composite structure of concrete-filled steel tublar shows that the latticed wind turbine tower of concrete-filled steel tubular(CFST)combines the advantages of concrete structure and steel structure and has high reliability,but most of the joints are intersecting joints and tube-plate joints,and it is difficult to control the welding quality and repair the broken joints.Based on this,this paper proposes a new type of spherical plate enveloping joint,and experimental research and finite element analysis on its mechanical performance in the plane model of the latticed concrete-filled steel tubular wind turbine tower are carried out.The main research contents and results are as follows:(1)The prototype size of the three-limb latticed concrete-filled steel tubular wind turbine tower was preliminarily made,and its wind load,aerodynamic thrust and fan gravity were calculated.The analysis of internal force and displacement was carried out in combination with SAP2000.One of the prototype tower was selected,and according to the scale scale obtained by the similarity theory,two groups of latticed concrete-filled steel tublar wind turbine towers with spherical plate joint plane specimens were designed,and low-cycle repeated horizontal load tests were carried out.Solidworks was used to build the plane model of the latticed concrete-filled steel tubular wind turbine tower,and ABAQUS was imported to carry out the finite element numerical simulation and parameter extension analysis.The influence law of ultimate bearing capacity,ductility,energy dissipation capacity and failure pattern of the pylon was studied by experiment and finite element analysis.(2)The test results show that the stiffness of the web member has a great influence on the hysteretic performance of the tower,the compression of hysteretic curve can be reduced by increasing the stiffness of the web member;The stiffness ratio of the web member-column(?)was increased from 0.04 to 0.09,and the ultimate bearing capacity and displacement ductility coefficient of the tower were increased by 34.7% and 39.5% respectively;The failure modes are all failure of the materials of ball column fractured,buckling and instability of three-layer inclined web,and tear and failure of top layer transverse web.(3)The finite element analysis shows that the ultimate bearing capacity and ductility of the tower are increased with the increase of the stiffness ratio of the web member-column.When the stiffness ratio(?)exceeds 0.07,the increase of the ultimate bearing capacity and ductility will slow down.When the ball-column is welded to the trapezoidal joint plate,the ultimate bearing capacity of the tower is increased by 38.4% which compared with that of the bolt connection,and the ductility coefficient is slightly reduced by 1.9%~7.5%.It is suggested that the stiffness ratio of the web member-column(?)should be 0.06~0.07.On the premise of meeting the carrying capacity,the thickness of the platen of the joint region should be reduced appropriately to give full play to the material properties,and some measures should be taken to strengthen the connection strength of the ball column. |
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