Development of Aluminum Decks Using Friction Stir Welding

由于使用搅拌摩擦焊（FSW）开发的铝甲板由封闭部分组成，因此无法目视检查FSW接头的背面。本研究设计了一种开闭型铝合金桥面板，在开闭型截面上进行搅拌摩擦焊，可以对节点背面进行目视检查。设计了在封闭型截面上翼缘两侧设置悬挑的挤压件。挤压件的悬伸端对接，并在那里进行FSW。当没有水平加劲肋时，钢梁按腹板伸长比的极限值制造。三个钢栓钉剪力连接件焊接到钢梁的上翼缘，在桥横向方向上成一排。围绕立柱铺设了模板，以便在钢梁的顶部翼缘和铝合金外墙的底部翼缘之间留下支撑砂浆。 关于我们 鲁辛螺柱通过底部凸缘上的矩形切口插入挤出件内部。通过挤出件的顶部凸缘上的孔填充不收缩砂浆。对铺设在钢梁上的铝合金桥面板进行了静载试验，铝合金桥面板现场连接采用摩擦型高强钢螺栓。为了保证铝合金构件表面的摩擦力，对控制粗糙度的试件进行了拉伸试验，给出了铝合金构件表面粗糙度与摩擦系数之间的关系。为了确认极限强度和疲劳强度，对铝桥面板的两侧和两端进行了现场连接。在将铝桥面板与钢梁连接时，由于铝和钢的热膨胀系数相差两倍，因此，随着温度的变化，铝桥面板上可能会产生不可忽视的应力。因此，必须明确铝桥面与钢梁之间的复合作用程度。为此，制造了铝桥面和钢梁的组合梁。少

Since the aluminum deck that had been developed using the Friction Stir Welding(FSW), consisted of closed sections, it was impossible to examine visually the back surface of the FSW-joints. In this research, an aluminum deck of open-closed sections was newly designed, where conducting FSW on the open sections made the visual inspection of the back surface of the FSW-joints possible.The extrusions where overhangs were provided on both sides of the top flange of the closed section were designed. The ends of the overhangs of the extrusions were butted, and FSW was done there. The steel girders were fabricated at the limiting value of the web slenderness ratio when no horizontal stiffeners are provided. Three steel stud shear connectors were welded to the top flange of the steel girders in one row in the bridge-transverse direction. A form work was laid surrounding the studs to leave the supporting mortar between the top flange of the steel girders and the bottom flange of the aluminum ext … More rusion. The studs were inserted inside the extrusion through a rectangular cutting on the bottom flange. The non-shrinkable mortar was filled through the hole on the top flange of the extrusions. Statically loading tests of the aluminum deck laid on the steel girders were carried out.The friction-type high-strength steel bolts were used for the on-site connections of the aluminum decks. To secure the friction on the surface of the aluminum members, the tensile tests of the specimens where the roughness was controlled were carried out, and the relation between the roughness of the aluminum members and the coefficient of friction was given. The on-site connections were fabricated for both of the sides and the ends of the aluminum decks, to confirm the ultimate strength and fatigue strength.When connecting aluminum decks to steel girders, since the coefficients of thermal expansion are twice as different between aluminum and steel, there may be a possibility that the stress which can not be ignored is produced in the aluminum decks according to the temperature change. Therefore, the degree of the composite action between the aluminum decks and the steel girders must be clarified. For this, the composite girders of the aluminum decks and the steel girders were fabricated. Less