Effects of point of load application on the lateral instability and post-buckling behaviour of zee and channel shaped beams | |
| Author | Anwar, Naveed |
| Call Number | AIT Thesis no.ST-88-3 |
| Subject(s) | Structural stability Buckling (Mechanics) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The effects due to the arbitrary location of the load point on the buckling and post buckling behaviour of thin walled open section have been investigated. The governing differential equations and corresponding stiffness matrices have been derived, based on the virtual work equation of linearized finite displacement. This extended stiffness matrix has been incorporated into the finite element model of Hasegawa et. a1 17 to trace the nonlinear displacement path. A r educed stiffness matrix (8x8) is derived for the evaluation of critical buckling loads. The finite element formulation presented in this study gives excellent agreement with the available solutions for the determination of t he critical lateral-torsional buckling loads. Location of load point greatly effects the buckling loads, post-buckling behaviour, allowable stresses and ultimate strength of beams. This effect is magnified by increasing the b/h ratio. Although zee and channel sections show a large reserve of post-buckling strength as compared with I-section , but t his reserve strength corresponds to fairly large stresses and displacements. For very s l ender beams, zee and channel sections carry higher loads than corresponding I -section, where as for wider flange widths , I -section is more economical . Flange width to web height ratio has a greater effect on the load displacement behaviour of zee and channel sections than on that of I-section. In I and zee sections, first yielding and maximum stress is observed in compression where as in channel section it occurs in tension. AISI specifications for the design of laterally unsupported beams grossly underestimate the strength of very slender zee and I-section beams, where as the strength of channel sections is highly overestimated when load is not applied through the shear centre . |
| Year | 1988 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Hasegawa Akio |
| Examination Committee(s) | Worsak Kanok-Nukulchai ;Sritawat Kitipornchai |
| Scholarship Donor(s) | Royal Netherlands Government |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1988 |