Research On Member Structures Vulnerability Based On The Topological Configuration

Vulnerability reflects the ease of structure damage in the civil engineering field, but there is a unified and effective structural vulnerability assessment system and theoretical methods have not yet formed. Based on the structure topological configuration vulnerability, from simple planar truss structures- a triangular steel truss starts, on this basis the vulnerability theory will be extended to the space truss structures- single cylindrical reticulated shell’s vulnerability analysis. The main research work is completed as follows:Firstly, introduced the vulnerability analysis process based on the structure topological configuration theory, a detailed description of the two processes of structural vulnerability analysis- the clustering process and unzipping process. Clustering process gives the structure clusters evaluation, specific steps of clustering to get the hierarchical model of structure configuration; the unzipping process gives the structure cluster vulnerability assessment index,specific steps of unzipping, looks for the most vulnerable structures failure scenario.Secondly, corresponding MATLAB vulnerability analysis program were compiled to apply to the five triangular steel roof trusses structure based on the theory of structural topological vulnerability. It was found that only rely on increased the member cross-sectional area to improve structural well-formedness does not necessarily guarantee to reduce structural vulnerability. It should be reasonable to optimize the member cross-sectional, so that the structure can achieve the best overall performance. The mechanical properties of the triangular steel roof trusses structure were analyzed by ANSYS in the actual load cases.Compared with the results of vulnerability analysis, showed that corresponding node displacement in the most vulnerable failure scenario reached the maximum, at the same time the rods stress were relatively higher.The results showed that the vulnerability analysis methods adopted can reflect the vulnerable parts of the structure effectively, while revealing weaknesses in the structure.Finally, the nine kinds of single-layer cylindrical reticulated shell vulnerability have been analyzed, prepared cylindrical reticulated shell MATLAB vulnerability analysis program and ANSYS command stream program. Get weak parts of a single layer cylindrical reticulated shell structure is the most outer shell net longitudinal edges and diagonals end side lever. With the single-layer cylindrical reticulated shell cross-section increases, structural well-formedness of the increase; with cylindrical reticulated shell length increases, the degree of reduction of structural well-formedness. Studied single cylindrical reticulated shell loads atEl-centro wave three to seismic action- the whole process of displacement to find structural dynamic ultimate load. Proposed structural well-formedness of the network as a single cylindrical shell internal connection performance evaluation index, the greater the structural well-formedness of the internal connection performance is stronger, the higher the structural dynamic ultimate load. ANSYS analysis found out that single cylindrical reticulated shell structure the larger forces parts belong to the weak parts of the vulnerability analysis. Provide a new way for large space truss structures vulnerability analysis, that direct calculate internal larger forces which vulnerability parameters rod determines the structure vulnerability, to find the whole structure failure mode.Vulnerability analysis theory based on the topological configuration is simple and efficient, the analysis results is universal. Provide a simple and easy theoretical method for the already built structure health monitoring, repair and reinforcement and pending the preliminary design, and structure construction control.