Time-Varying Mechanical Analysis of Long-Span Spatial Steel Structures Integral Lifting during Construction Process

Due to the size limitations of shaking tables, dynamic scale models of large-span space structures for engineering have small cross-sections and thin wall thicknesses. It is difficult to use the structural steels commonly used in prototypes to make dynamic scale models. In this paper, 304 stainless steel is proposed for making the scale model, and the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model was studied. Firstly, a uniaxial test was conducted to study the elastic modulus similarity and the yielding stress similarity. The test results demonstrated that the elastic modulus similarity ratio was 1:1, and the stress similarity ratios of the 304 stainless steel and the three typical structural steels were 1:1 (Q235 steel), 1:1.5 (Q355 steel) and 1:1.8 (Q420 steel). Then, the similarities of other variables were derived using the dimensional analysis method. In the end, a numerical analysis was conducted to verify the similarity relationship between the structural-steel prototype and the 304-stainless-steel dynamic scale model. In the numerical analysis, a single-layer spherical reticulated shell structure and a dynamic scale model with a length similarity ratio of 1:20 were established by using the ABAQUS 2021 software, and the node displacement, the element internal force and natural vibration characteristics were analyzed. The results show that standard deviations of the displacements, the internal forces and the natural vibration frequencies between the prototype and the scale model were within 5%. It turns out that the proposed similarity between the structural-steel prototype and the 304-stainless-steel dynamic scale model was applicable in the elastic stage. The findings provide a reference for designing a dynamic scale model of large-span space structures for engineering by using 304 stainless steel.

On the Similarity Relationship between the Structural-Steel Prototype and the 304-Stainless-Steel Dynamic Scale Model

Xu,

Wang,

Liu

2023

Study on Inverse Analysis Technique Considering Influence of Construction Procedure on Performance of Large-Span Steel Latticed Arch

Wang,

Dai,

2024

In this paper, the influence of the construction process of large-span steel latticed arch on the geometric configuration and bearing capacity performance of the large-span steel latticed arch is calculated and analyzed by using the inverse analysis technique. By comparing the calculation results of single pre-deformation adjustment of the node co-ordinates in zero state of the whole structure and the dynamic adjustment of the node co-ordinates of the unconstructed part of the structure, it is found that the inverse analysis method of dynamic node co-ordinate adjustment is used to achieve the unification of the geometric configuration of the final structure and the bearing capacity performance of the structure. The results show that the inverse analysis method of dynamic node co-ordinate adjustment proposed in this paper can simulate and track the dynamic changes of structural geometry and stable bearing capacity performance in the actual construction process, which can not only consider the influence of the installed part of the structure on the co-ordinate adjustment value of the uninstalled part of the structure but also consider the deformation influence of the subsequent uninstalled structure on the installed structure and can realize the optimal approximation of the final state structure to the geometric configuration of the zero state structure and the accurate calculation of the bearing capacity performance with the progress of the construction process.

Analysis of Mechanical Properties during Construction Stages Reflecting the Construction Sequence for Long-Span Spatial Steel Structures

Yao,

Li,

Yang

et al. 2024

When constructing long-span spatial steel structures, the unformed structure is often incomplete and unstable. The construction sequence significantly influences the mechanical state of the structure during the construction stages (CSs), affecting both the path and time effects. This study examined the mechanical properties of the construction process using an actual project as a case study, comparing two methods: one-step forming and stage-by-stage forming. Critical turning points of stress and displacement during the CSs were identified as the initial installation and unloading stages. Stress concentrations frequently occurred at temporary support points, and peak displacements often appeared at the outer overhanging bars of the structure. A well-planned construction sequence can effectively manage the structure’s formation, boundaries, and loading to ensure construction safety and stability. The conclusions and analysis methods from this study provide valuable references for the design and construction of similar long-span spatial steel structures.