Study On Optimization Design Of Large Span Single-layer Reticulated Shell

In recent decades,with the rapid development of economy and the continuous improvement of science and technology,the long-span space structure has been developed vigorously as a new type of space structures.As a kind of long-span space structures,the space reticulated shell structure is widely used in large-scale stadiums,long-span station waiting rooms and large industrial and civil buildings due to its characteristics such as less steel consumption,light weight,graceful appearance and reasonable overall structural performance.With the improvement of people’s architectural aesthetics,the span of buildings is also increasing.In order to satisfy the requirements of the strength and stiffness of the structure,the traditional design method is to increase the cross-sectional size of the components,which will inevitably result in the waste of steel and poor economic efficiency.Therefore,it is practical and significant to optimize the design of long-span space grid shell structure with complex structure,high investment and high risk,because it can not only meet the needs of the construction project,but also conform to the building of a resource-saving society in china and is conducive to sustainable development.Based on the current status of the optimal design of the long-span space grid shell structure,the research work in the thesis includes the following aspects:Taking into account the actual situation of the lighting top single-layer reticulated shell structure of an office building in HuaWei Production Park and its spatial integrity,the finite element model which is in line with the actual situation of the project is established by using ANSYS.Under the premise of satisfying the constraints of structural strength,stiffness,deflection and stability,the objective function is established with least amount of steel in single-layer reticulated shell structure.Then according to the current load specification,a total of seven conditions were selected and the optimization module in ANSYS was used to optimize the structure.Comparing the data before and after optimization,the total steel consumption of the single-layer reticulated shell structure after optimization is reduced by about 21%,which shows the significance of the optimization effect.Through the static analysis,modal analysis,stability analysis and flexible time history analysis of the structure before and after the optimization,the corresponding displacement and stress of the structure are calculated and analyzed.Although the cross-sectional area of the optimized structure is smaller than the previous one,the stress-bearing performance of the structure as a whole is improved and it meets the requirements of the current code of practice and makes the performance of materialsmore fully exerted.At the same time,the rationality and reliability of the single-layer reticulated shell structure after the optimization are verified,which improves the economic benefits to a certain extent and provides some reference values for the future optimization design and analysis of the large-span space reticulated shell structure.