| Author | Hoang Nam |
| Call Number | AIT Thesis no.ST-98-02 |
| Subject(s) | Structural dynamics
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Numerical response predictions of simple linear structures under stochastic wind field are normally performed in the frequency domain for the sake of computational expedience. For the modem scope of complex structures, the time-domain approach offers a promising alternative. This is a rather new approach in which numerical simulation of wind turbulence is a critical element. In this study, wind turbulence is simulated as time-histories of fluctuating along wind velocity by the Auto Regressive Moving Average (ARMA) method. The coefficient matrices associated with the ARMA model are determined according to the prescribed statistical properties of wind turbulence in the frequency domain (e.g. spectral density and coherence functions). Once these coefficient matrices are found, the fluctuating wind velocities can be recursively generated. A computer program following this procedure has been developed. Furthermore, in order to verify the validity as well as reliability of the approach, another program which aims to accurately estimate statistical characteristics of a random process from its samples is written. Various checks on the simulated results are then carried out. Also, two parametric studies to examine the effects of order of ARMA model and sampling time interval on the accuracy of simulation are conducted. The results show that wind turbulence can be simulated extremely well by the ARMA model with low order and small sampling time step. This is seen from the good matching between the target properties and the correspondings computed from generated sample functions of wind fluctuation. The ARMA method has thus been proved to be potential. for time-domain solutions of complex wind engineering problems involving stochastic loads. |
| Year | 1998 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pennung Warnitchai; |
| Examination Committee(s) | Worsak Kanok-Nukulchai ;Wijeyewickrema, Anil C. ;Kishi, Toshiharu; |
| Scholarship Donor(s) | Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1998 |