Application of model reduction tools in analysis of wind-induced pressures on low-rise buildings

Abstract

Recent advances in laboratory and field measurement techniques and numerical simulations of wind-induced loading on buildings and structures made possible generation of large data sets, suitable for database-assisted wind-resistant design. In parallel, data reduction tools have been developed to aid storage, management and accessibility issues associated with large datasets/databases. In the presented research, application of such tools in analysis of stationary and non-stationary wind-induced pressures on a generic low-rise building is discussed. Both stationary and non-stationary cases are addressed. In stationary analyses, Proper Orthogonal Decomposition (POD) and Method of Snapshot (SPOD) were used to identify the most energetic spatio-temporal structures of the pressures. Linear Stochastic Estimation (LSE) and Gappy POD (GPOD) were employed to generate the pressures at specified target locations via extrapolation of the pressures provided at chosen reference locations. Optimized reference positions were determined using algorithm-based and empirical approaches. In non-stationary analyses, Wavelet De-noising and Two-Stage-Moving-Averaging were applied to decompose the non-stationary pressure into time-varying mean, standard deviation and normalized fluctuation. The techniques developed for stationary pressures were adapted for non-stationary cases. In analysis of the stationary data, the extrapolation techniques (GPOD and LSE) were found to reduce the data more efficiently than the modal reduction tools (POD and SPOD). In pressure extrapolation, LSE provided more accurate pressure predictions than GPOD. A hybrid approach combining the use of GPOD, with algorithm-based reference positions selection, and LSE extrapolation enabled the most efficient capturing of the primary and secondary spatio-temporal features of the pressure. This technique is recommended for analyses focused on development of reduced models of wind pressures induced on low-rise buildings. In the non-stationary investigations, the hybrid GPOD-LSE technique, developed in analysis of the stationary pressures and modified for the non-stationary cases, led to accurate pressure predictions and model reductions. This methodology appears to be a suitable tool for similar analyses of non-stationary wind-induced pressures on low-rise buildings. Follow-up investigations of stationary and non-stationary cases are recommended to assess potential for further optimization of the developed techniques and their application in analyses of wind-induced loading on other buildings and structures.