对4个钢管混凝土风力发电机塔架K型相贯节点进行了单调静力加载试验,同时进行了1个钢管K型相贯节点的对比试验.研究了这两种相贯节点的破坏机理和破坏特征、节点进入塑性后的变形发展过程以及相贯线附近的复杂应力状态和分布规律.试验结果表明:由于混凝土的存在,钢管混凝土相贯节点的失效模式与空钢管相贯节点完全不同,钢管混凝土节点发生了受压腹杆的局部屈曲和整体弯曲,塔柱管壁没有明显塑性变形;而空钢管节点的失效模式为塔柱钢管表面塑性失效.两种节点在相贯线附近的应力分布也不相同,钢管混凝土相贯节点在受拉腹杆接头处鞍点位置的应力最为集中,远超过钢材的屈服强度,其他测点处仍处于弹性受力阶段;空钢管相贯节点在相贯线附近的测点均屈服,应力峰值在冠点附近.本次试验结论可为钢管混凝土K形焊接相贯节点的设计提供参考。
Four concrete-filled steel tubular(CFST) welded K-joints in wind turbine tower were carried out on the monotonous static load experiment.At the same time the contrast test on a hollow steel tubular welded K-joints was carried out.The failure mechanism and failure characteristics,deformation development process after entering the plasticity stage,the complex stress state and distribution laws near the intersecting line of the two tower joints were all studied.Experimental results show that due to the existence of the concrete,the failure mode of the CFST welded joints was completely different from the hollow steel tubular joint,and happened the local buckling and overall bending of compression web members took place with the CFST welded joints.At the end of the test tower column walls no obvious plastic deformation appeared;while the failure mode of hollow steel tubular joint was the plastic failure of the tower column wall.The stress distribution near the intersecting line of the two tower joints were also different,with the stresses of the CFST welded joints mainly concentrating at the saddle points at the tensile web layup,which were far more than the yield strength of steel,while the other points were still in the elastic stress stage.The measuring points near the intersecting line of hollow steel tubular joints yielded and the stress peak was near the coronal points.The test results can provide reference for design of CFST welded K-joints.