Typhoon-induced debris movement and impact damage analysis of structural envelopes

The windborne debris is one of the most important causes of the envelop destruction according to the post-damage investigations. The problem of windborne debris damage could be summarized as three parts, including the windborne debris risk analysis, debris flying trajectories, and impact resistance of the envelopes analysis. The debris source regions are graded based on the environment around the structures and the distributed degree of the buildings; meanwhile, the method of debris distribution is developed. According to the different aerodynamic characteristics, the flying trajectories of plate-like debris are solved by using numerical method; furthermore, the numerical results are compared with the test data and numerical solutions of the literature and show a good agreement. The trajectory equations of compact debris are improved by considering the vertical wind load caused by a wind attack angle, which accords with the real typhoon situation better. The impact resistance of the envelopes is analyzed. Besides, the process of windborne debris damage analysis is described in detail. An example of industrial building is given to demonstrate the whole method by using the observed data of typhoon Chanchu (No.0601). The method developed in this paper could be applied to the risk assessment of windborne debris for structures in wind hazard.