Estimation Method of Wind-Induced Fatigue of Metal Roof Claddings under Typhoon: Numerical Analysis and Experimental Comparison

Abstract

Equivalent load cycle sequence (ELCS) is important basic information to know that affects the reliability of the evaluation of wind-induced fatigue on metal roof claddings. In this study, an estimation method of wind-induced fatigue of metal roof claddings is proposed. Based on the measured wind pressure–time history data of the roof claddings on a full-scale low-rise building located along the coast of South China during a typhoon, a new ELCS (NELCS) that reflects typhoon and actual structure wind pressure characteristics in China’s coastal areas is obtained by using the rainflow counting method. The locations of fatigue hot spots of metal roof panels are analyzed by using the finite element analysis method, and the relationship between hot spot stress and wind pressure is obtained. The fatigue damage accumulation of metal roof claddings under the ELCS of a typhoon process is counted by the linear cumulative fatigue theory, commonly known as Miner’s rule. The fatigue damage accumulation of roof claddings with different purlin distances and design wind loads is analyzed using this method and then compared with the results from the dynamic loading test of an air chamber. Results show that the physical test findings are close to the numerical calculation results, which proves that the numerical calculation method has high accuracy and reliability. The comparison between NELCS in this study and the Australian standard low-high-low (LHL) sequence shows that the LHL loading sequence is conservative.

Wind Pressure Field Reconstruction and Prediction of Large-Span Roof Structure with Folded-Plate Type Based on Proper Orthogonal Decomposition

“…Due to the large number of test conditions and the huge amount of data, only the results under 6 characteristic wind direction angles are selected for display, as shown in Figure 5. According to Figure 5, it can be found that: (1) The flow separation phenomenon will occur at the edge of the roof, and the negative inclination angle delays the reattachment phenomenon, so that under the action of any wind direction angle, the mean wind pressure coefficients of the roof are mainly negative. The mean wind pressure coefficients of the folded plate surface with a negative inclination angle are all negative in the According to Figure 5, it can be found that: (1) The flow separation phenomenon will occur at the edge of the roof, and the negative inclination angle delays the reattachment phenomenon, so that under the action of any wind direction angle, the mean wind pressure coefficients of the roof are mainly negative.…”

“…According to Figure 5, it can be found that: (1) The flow separation phenomenon will occur at the edge of the roof, and the negative inclination angle delays the reattachment phenomenon, so that under the action of any wind direction angle, the mean wind pressure coefficients of the roof are mainly negative. The mean wind pressure coefficients of the folded plate surface with a negative inclination angle are all negative in the According to Figure 5, it can be found that: (1) The flow separation phenomenon will occur at the edge of the roof, and the negative inclination angle delays the reattachment phenomenon, so that under the action of any wind direction angle, the mean wind pressure coefficients of the roof are mainly negative. The mean wind pressure coefficients of the folded plate surface with a negative inclination angle are all negative in the downwind, while the coefficients of the folded plate surface with a positive inclination angle have positive values in some areas, but the positive pressure value is very small, that is, the roof is mainly subjected to upward lift under different wind direction angles.…”

“…The large-span roof structure has the characteristics of light weight, large flexibility, small damping, low natural vibration frequency, and dense mode shapes, and its main mode shapes are not concentrated in the first few orders like high-rise buildings, which makes it more sensitive to the effect of wind. Cases of wind-induced disasters caused by excessive wind force are not uncommon [1][2][3][4]. Therefore, it is of great significance to reasonably and effectively predict the wind load of the large-span roof structure to improve its wind resistance performance.…”

Fatigue of Mechanical Structures from Cyclic Wind Actions

“…As for the static loads, their determination is relatively easy since their data are obtained through standards [2] for specific areas, different heights of structures, structural factors, etc. Conversely, the dynamic load [3,4] is more difficult to determine since the recognition of the cyclic characteristics of the wind load is more difficult.…”