Numerical Simulation Of Non-uniform Solar Temperature Field And Its Effect On Large-span Latticed Shell Structures

In this paper,the super large-span reticulated shell structure is selected as the research object.The complex thermal environment parameters of structural non-uniform temperature field are calculated.Considering the geographical position of the structure,the change of the sun angle,the shadow between structural members,etc.,the shadow occlusion relationship between structural members under solar radiation is analyzed in detail,and the occlusion coefficient of each member is calculated.Under the typical conditions of summer and winter,the structural non-uniform temperature field is simulated by using the ANSYS software.Based on the temperature field results,the structural non-uniform temperature effect is also explored.By the comparison with the uniform temperature effect specified in the current specification,the temperature effect distribution law of super large-span reticulated shell structure in summer and winter is obtained.The research results can provide theoretical basis and technical guidance for thermal deformation analysis,working performance analysis and thermal control of kilometer-scale super large-span structure.The main study contents and contributions as follows:(1)Combined with the 3D3 S design software,the analysis model of a double-layer Kiewitt spherical reticulated shell structure with a span of800 m and a rise-span ratio of 1/4 is established in the thermal analysis and structural analysis module of the finite element software ANSYS.According to the basic theories of heat transfer,the environmental boundary parameters required in the process of thermal analysis are determined,and the thermal load calculation program is developed by APDL language.(2)On the basis of the practical situation,the causes of sunlight shadow are analyzed.The ray-casting algorithm,which can effectively evaluate the shadow effect on structural temperature field,is proposed based on the hidden-line algorithm of computer graphics.The shadow occlusion coefficients of each member under the typical conditions of summer and winter are obtained by this method.It shows that the solar radiation of structural members is significantly affected by shadows.(3)The non-uniform temperature field of super large-span reticulated shell structure under the typical conditions of summer and winter is analyzed by numerical simulation method.The consideration of shadow effect is of great significance to improve the accuracy of temperature field analysis results.The temporal and spatial characteristics of the structural temperature field variation are mastered.(4)On the foundation of the actual temperature field results,the structural non-uniform temperature effect is calculated by numerical method.Compared with the structural temperature effect produced by uniform temperature field,the varying and distribution laws of the non-uniform temperature deformation and stress are summarized.It is proved that the influence of non-uniform temperature distribution on the temperature effect of the super large-span structure can not be ignored.