Effects of geometric non-linearity of structures on response to random wind loading | |
| Author | Theeraphong Chanpheng |
| Call Number | AIT Thesis no. ST-99-11 |
| Subject(s) | Structural dynamics 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 | Structural models of string and suspended cable subjected to random wind loading can be described by the systems of equations including explicit nonlinear terms due to finite deformation. The effects of these nonlinear tenns or geometric non-linearities are revealed by investigating into time series of responses computed by time domain approach. By Auto Regressive Moving Average (ARMA) method, time series of wind turbulence are simulated and then transformed into wind force by quasi-steady assumption. Subsequently, Newmarkextrapolation algorithm, which is highly efficient in minimizing numerical damping and period error, is applied to compute time histories ofresponses accurately. In order to represent behaviors of actual structures, parameters of string are of a typical stay cable and parameters of suspended cable are of a conductor on transmission line towers. The responses computed by time domain approach are verified by those computed by frequency domain approach in case of string described by linear structural model. Good agreement is found in the verification. From the results of nonlinear string, cubic non-linearity induces weakly nonlinear behaviors in in-plane vibration. In out-of-plane vibration, although effects of nonlinearity are obvious, amplitude of vibration is .so small that dynamic characteristics can be ignored. The investigation of string shows that there is a tendency of weak effects of geometric non-linearity when actual stay cables have the values of non-dimensional parameters in the range of values in this analysis. From the results of nonlinear suspended cable, severe vibrations in both in-plane and out-of-plane motions as well as severe dynamic characteristic of tension are observed. These are mainly resulted from quadratic non-linearity. The effects of non-linearity of suspended cable in this analysis show that in analysis of any conductors on transmission line towers, geometric non-linearity should be included. |
| Year | 1999 |
| Type | Thesis |
| School | School of Engineering and Technology |
| 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;Pennung Warnitchai; |
| Examination Committee(s) | Worsak Kanok-Nukulchai;Wijeyewickrema, Anil C.;Pruettha Na Nakorn; |
| Scholarship Donor(s) | Government of Japan.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |