Weak Parts Of Structure Research Articles

Study on the Seismic Optimization Scheme of Steel Bundled-Tube Structure with Vertical Setback

In order to improve the seismic performance of vertical setback steel bundled-tube structure and meet the dynamic multi-objective requirements of seismic performance-based design, the optimization effects under rare earthquakes on the zone of fortification intensity 7 and 8 in China are researched by improving members stiffness and adding dampers in the weak parts of structure, based on dynamic elastic-plastic analysis. The results show that: 1) Under rare earthquakes on the zone of fortification intensity 7, increasing the stiffness of weak skirt beam can improve the seismic performance of spiral and symmetrical setback structure; 2) For the spiral setback structure, under rare earthquakes on the zone of fortification intensity 7, the damper can only be arranged at the junction of the first layer of the setback frame unit and the frame unit without setback. However, under rare earthquakes on the zone of fortification intensity 8, it is not advisable to install dampers at the weak areas; 3) After incorporating dampers at the weak areas of symmetrical setback structure, the optimized members experienced a reduction in stress levels, significantly decreased the inter-layer displacement angles with a maximum reduction of 43%, and the optimization effect is significant.

Failure mechanism of subway structure with different central columns based on Daikai Station

The central columns of the Daikai Station in Kobe City were severely damaged due to Hanshin earthquake in the year 1995, leading to serious ground collapse. To evaluate the behavior of underground structures, the finite element model of Daikai Station was established using ABAQUS, and benchmarked against the measured data. Furthermore, the central column was replaced by concrete-filled steel tube (CFST) column to illustrate the response under the earthquake action. Results show that the central column of the station is one weak part of structure. Compared with the ordinary reinforced concrete (RC) structures, using CFST central column can enhance the overall rigidity of the structure and greatly improve the seismic performance of the underground structures.

Study on the dynamic identification method of the weak part of the bar-shaped combined structure

The weak part of the stiffness of machine tool combined structure is the key to improve the stiffness of machine tool. To overcome the static deformation with difficulty acquisition, the paper chooses machine tool combined structure which can be equivalent to one-dimensional bar structure, and a weakness index (WI) is proposed to identify the weak part of the stiffness by means of the dynamic hammer test method. Based on the bar structure as a numerical example, the weak parts are modeled as EA reduction in stiffness while the mass is maintained at a constant value. Thorough finite element (FE) method simulations are performed to assess the robustness and limitations of the method in several scenarios with single and multiple weakness. On the crossbeam of gantry type machine tool, the sensors are used to collect vibration data, the structural modal parameters are obtained by singular value decomposition (SVD) technique, and the dynamic characteristics are systematically reconstructed by using modal state space method to obtain stiffness data at zero-frequency. Then, the weak part of the structural stiffness is identified by the weakness index. Finally, the comparison of FE simulations and experiment results are provided to illustrate the working of the method.

Theoretical Model and Mechanical Performance of Semi-Integral Abutment Jointless Bridge

Expansion joint of a bridge is a weak part of structure, it leads to early structure destroy and reduces the bridge life. The paper put forward a new type of Jointless Bridge --- Semi–Integral Abutment Jointless Bridge, and its theoretical model was built. An engineering of four spans 100m length Prestressed Concrete Semi–Integral Abutment Jointless Bridge was analyzed, and results that its mechanical performance is so excellent that it should be wide applied in bridge engineering.

The Stiffness Analysis of a Mechanical Gantry under Torsion

When a heavy torque load acts on a kind of mechanical gantry, its largest deformation displacement must not be larger than the given upper limit value. So we must make an accurate deformation analysis of the whole structure of the gantry. This paper introduces the analyzing process of the main structure stiffness of the gantry. According to the calculating results , the weak part of structure is found. This part arouses the main deformation of the gantry when loaded. Then a solution is made for it. The stiffness analysis of the gantry is also performed using a FEA software. By comparing the computing results of the two methods, an analysis of the respective computing characteristics and limits of them is given, and a reference for the stiffness analysis of the similar equipments is provided.

The Review about a New Type of Bridge Structure — Semi–Integral Abutment Jointless Bridge

It was well known that expansion joint of a bridge was a weak part of structure, it led to early structure destroy and reduced the bridge life. Basing on Life-Cycle Design of bridge structure , a new type of optimum bridge structure --- Semi–Integral Abutment Jointless Bridge was put forward. Firstly the new bridge structure was defined and its performance was described. Then several problems that included temperature effect, the interaction of structure-soil etc were discussed about the application of the new bridge structure. Finally the conclusion is the Semi–Integral Abutment Jointless Bridge is a kind of durable bridge structure that has rational mechanical performance and great practical value.