Investigation On The Mechanical Behavior Of Ring-Sleeve Joint Of Single-Layer Spatial Reticulated Structure

The Single-layer spatial reticulated structure is widely used in the world because of its mechanical behavior and good shape. For example, the Nagoya Dome in Japan, the Mercedes-Benz Superdome in America, the Sum Valley of Expo 2010 Shanghai and so on. Tube and Joint are two important components of single-layer spatial reticulated structure. The mechanical behavior of the joint, such as strength, bending stiffness, highly influences the mechanical behavior of structure. Currently there are four types of joints as mainly used in spatial grid projects, such as Welded hollow spherical joints, Bolt-sphere joints, Member joints and Embedded hub joints. They are both welded joints except the Embed hub joints. The Embedded hub joints cannot be widely used because of its low strength and stiffness. Assembled structure is better than welded structure in economics. In Germany, assembled joints are widely used in the Single-layer spatial reticulated structure, but in China, most single-layer spatial reticulated structures are using welded joints.In this paper, a new type of assembled joint which is suitable for single-layer spatial reticulated structure is put forward. It’s called Ring-sleeve joint. Prototype static experiments and numerical analyses were conducted to study the mechanical behaviors of this joint. The main work of this dissertation includes the following five aspects:(1) A new type of assembled joint which is suitable for single-layer spatial reticulated structure is put forward. The status of members in structures is obtained by designing a single layer geodesic latticed shell. According to the force transmission in the joint, we design the parameter of the joint. There are 15 joints in this paper. There are 6 parameters, including the quantity of bolts, the diameter of bolts, the Spacing of bolts, the length of sleeve, the length of joint and the F-N ratio.(2)The test device is designed according to the condition of the laboratory. The device works well. The steel material test is carried out.15 experiments are finished. We obtain the failure mode and failure process of the joint.(3) Numerical analyses were conducted for the 15 joints using ANSYS. We obtain the stress distribution of the joint and stress expansion. The results of experiment and numerical analyses fit well in strength and stiffness of the joint.(4)The results of experiment and numerical analyses are summed up to study the mechanical behaviors of this joint. The strength obtained by experiment, the strength obtained by numerical analyses and the strength obtained by formula are compared. The results show that, the joints have good plastic when it’s destroyed. Different parameters have different influences to the joint and we find the reasons. The thickness of sphere is highly influenced the mechanical behavior of the welded hollow spherical joint. To evaluate the bending stiffness and the strength of the joint, the behaviors of the joint was compared with rigid joints.(5)We offer the reference so the joint can be used in engineering project.