Analysis and Design of Steel Frame-Grid Wall Structure

The grid wall structure is a new type of lateral force resistance system obtained by meshing steel plate walls, which has the advantages of good seismic performance, light welding workload, convenient processing and transportation of components, convenient construction and installation, etc. It meets the current policy requirement of vigorously developing assembled steel structures. The current research on grid wall structures is mainly focused on mechanical properties, but it has not yet been applied in practical engineering design. In order to explore the feasibility of its application in practical engineering, based on the steel frame-steel plate shear wall structure of Building 9# of the Lanzhou New District Sheltered Housing Construction Project（Phase II）, the structural arrangement and design were carried out using steel frame-grid wall structure, the structural calculation model was established in YJK and MIDAS/Gen software, and the overall structural analysis, members load bearing capacity verification and key joints design and analysis were carried out under the same technical parameters and loading conditions. Elastic analysis of steel frame-grid wall structures in YJK and MIDAS/Gen was carried out to obtain the overall indices of the structures and compared with the overall indices of the original steel frame-steel plate shear wall structures. The results show that the lateral force-resisting members of the steel frame-grid wall structure are arranged regularly in plan and elevation, and the indicators obtained by both software are close to each other and meet the code requirements. Although its lateral stiffness is slightly lower than the steel frame-steel plate shear wall structure, the steel grid wall uses less steel and less welding work than the corresponding steel plate shear wall. When checking the load capacity of a member, as the calculating length method for T-section steel members of steel grid walls is not yet clear, it is unable to use the first-order elastic analysis method for member stability calculations, so the members were checked using the direct analysis method. Considering the overall initial defects and the component initial defects, the non-linear analysis under each load combination was carried out and the results showed that the strength stress ratios of all steel members are less than 1.0 and the load capacity of the members meets the code requirements. The fishtail plate, as the connecting component between the T-section steel components and the edge components, is essential for the energy consumption performance of the steel grid wall. To ensure the reliability of the connection, further analysis of the mechanical properties of the fishtail plate was carried out. A refined finite element model of the 3-story local substructure of this steel grid wall was established in the finite element software ABAQUS, and the analysis was carried out after applying the internal forces at the top of the columns, the loads on the beams and the lateral displacements at the top of the columns at each story under the load envelope combination. The results show that the fishtail plate, T-section steel components and edge components don′t yield under the design load, and when the lateral loading continues until the fishtail plate yields, most of the T-section steel components, the beam ends and the compressed side of the column footings at the ground floor have already yielded at this time, meeting the design requirement of "strong joints, weak components".