Comparative Analysis Of The Mechanical Properties Of Symmetrical And Asymmetrical Column Single Eaves Buildings In Ming And Qing Dynasties

The timber-frame structure of Chinese ancient building not only contain rich cultural,artistic and scientific information,but also have very important economic and social value.Targeted research on the structural characteristics and structural mechanical properties of the ancient wooden-structure can provide a certain theoretical reference for the reinforcement and protection of ancient buildings,as well as targeted reference materials for the construction and protection of ancient wooden structures with the same structural form.In this paper,the asymmetric layout of columns and trusses in the Ming and Qing dynasties was taken as the research object.By means of numerical simulation and comparative analysis,the influence of asymmetric layout of columns and trusses on the overall mechanical properties of single eaves buildings was studied.The main contents are as follows:(1)By studying the two structural layouts of the symmetrical and asymmetrical layout of the column structure of the single eaves purlin nine hip wooden structure,the similarities and differences in the structural structure of the symmetrical and asymmetrical layout of the column frame are analyzed.Taking the on-site measurement of the Xi’an Chenghuang Temple list,the single eaves purlin nine hip wooden structure as an example,the symmetrical and asymmetrical column layout is established.(2)According to the structural characteristics and structural mechanical properties of ancient buildings with symmetrical and asymmetrical column layout,the simplified principle of wood structural members is determined.The results of the SAP2000 finite element software calculation model are compared with the results of a hall model test of the Ancient Building Research Group of Xi’an University of Architecture and Technology.The rationality of the modeling method is verified,and the symmetry of the column structure of the single eaves purlin nine hip wooden structure is established.Symmetrical layout of the finite element model of the wood structure.On the basis of verifying that both wood structures meet the requirements of structural bearing capacity,the deformation and internal force distribution of the two structures under vertical constant load and lateral wind load are compared and analyzed.It is concluded that the asymmetric layout of the column layer improves the lateral stiffness of the structure and significantly reduces the concentrated force of the seven beams and the gold column.(3)Through modal analysis,response spectrum analysis and time history analysis of the two wood structures,it is concluded that the asymmetrical layout of the column structure is more prone to the torsion effect than the symmetrical layout of the column frame.With the increase of the peak value of the seismic wave,the damping and vibration isolation capacity of the asymmetrical structure of the column structure is more obvious.