Experimental research on dynamic tensile behavior of full-scale weld-necked flange joints used in transmission steel tubular towers

A new type of weld-necked flange (WF) joint is presented in this paper. The flange neck of the new WF joint adopts an inner-slope section with a taper angle ranged from 20° to 25°, with the flange plate being thicker than the traditional WF joint. Compared to the traditional WF joint, the bolt cluster circle of the new WF joint is reduced relative to the steel tube wall. As a result, the effect of tensile load eccentricity on the steel bolts is significantly reduced. A series of dynamic tensile tests is conducted on the new WF joint. The stiffness of the flange plate is of importance to reduce the prying force for the new WF joint. The thickness of the flange plate, which is an important parameter for the new WF joint, is investigated to study the effects on the new WF joint’s dynamic behavior. Meanwhile, the finite element model of the new WF joint is developed to study their dynamic tensile behavior. The finite element model is verified by experimental results and proved to be precise and reliable. Base on the finite element analysis, the dynamic stress distribution and contact pressure at typical locations of the new WF joints are better revealed. Afterwards, a simplified design model for the new WF joints under tensile force is proposed, which can meet the safety and economic requirements in practical engineering projects. Furthermore, the design model can provide valuable reference for the design of the new WF joints.