| Author | Annop Sriwongkham |
| Call Number | AIT Thesis no. ST-97-10 |
| Subject(s) | Cable structures
|
| Note | A thesis submitted in partial fulfillment of the requirements for degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-97-10 |
| Abstract | Cables and metallic rods have been widely used as structural members in modern engineering structures. The internal stresses in these structures are generally governed by the cable forces. Thus, during the construction and service life of the structures, it will be beneficial to be able to accurately identify the force in cables or metallic rods. One convenient way to access the force in practice is to use a dynamic identification method. This method is based on a vibrating string theory. For long cables, this method works very well because a long cable can be well represented by an ideal string model. However, as cable length decreases, the effects of bending rigidity on dynamic behavior of cable become more and more significant. Hence, the method may not work accurately for short metallic cables or rods. In this study, a new dynamic identification method for short cables is developed. The new method is based on a more realistic dynamic model of short cables where the effects of bending rigidity are taken into account. In addition, another dynamic identification method, modified from the new method, is also developed for the case where the mass of the cable is not accurately known. To check the validity and accuracy of these newly developed methods, an experimental investigation is carried out. Three circular-section steel rods with diameter of 16, 19, and 22 mm are chosen. Several tests are conducted. In each test, a rod is tensioned and fixed to rigid anchorages. The tension is then directly measured by a center-hole force sensor. For the dynamic identification, free vibration response and its Fourier spectrum is obtained by the use of a small-size accelerometer installed at a quarter span and a signal analyzer. Five or six tests under different levels of tension are carried out for each rod. The experimental verification proves the reliabity of the new developeded technique which can estimate cable tension with less than 3 % error. Another scheme of identification, which is developed for the case that the unit mass of cable cannot be accurately obtained, is proved to be reliable for estimating cable mass and tension with mainly less than 5 and 4 % error respectively. Moreover, bending rigidity of cable can also be identified in the same time of each identification with fair accuracy. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ;no. ST-97-10 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| 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.;Sutat Weesakul;Sutat Weesakul |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1997 |