Study On Integrity Analysis Of Fatigue Of Single-Layer Reticulated Shell

In the analysis of long-span structure, the wind load is dominant. Compared with double layer reticulated shell, the single layer reticulated shell has more flexibly rigidity. So single-layer reticulated shell is vibrated easily under the stochastic wind loads. The member stress in the structure change greatly, and the member came about fatigue damage easily. To ensure the safety of the single layer reticulated shell, it is necessary to analyze the fatigue-resisting performance of the single layer reticulated shell under the stochastic wind loads.By simulating fluctuating wind speed in time history according to Kaimal power spectrum with AR methods, load spectrums were obtained. After time history analyses of FEM and statistics of stress cycles history by rainflow counting algorithms, the total life method was adopted to obtain the fatigue damage of members. Fatigue performance of the single-layer reticulated shells was analyzed under different rise-span ratios and average wind speeds. The procedure of the fatigue analysis was programmed by APDL in Ansys.As examples the single-layer spherical shell and single-layer reticulated cylindrical shell were analyzed under the stochastic wind loads. Fatigue performance of the single-layer reticulated shells was analyzed under different rise-span ratios and average wind speeds. The fatigue damage of members were obtained, and fatigue regions of the structure were also found. Fatigue performance of single layer reticulated shells was related to the rise-span ratios, the average wind speeds and the structural vibration mode. It was shown the number of fatigue members increased gradually with the decrease of the rise-span ratio; the maximum fatigue damage of members increased with the decrease of the rise-span ratio.Some conclusions were summarized and the problems that should be studied further were put forward in the end of the dissertation.