AbstractThe problem discussed in the following thesis is that of the effect of stiffener dimension on the buckling of webplate subjected to bending. In Chapter one the problem of buckling is introduced generally and various examples of the use of horizontally stiffened webplates are mentioned. The theoretical background to the problem of the stability of plates both stiffened and unstiffened is contained in Chapter (2) together with reference to the advantages and disadvantages of various stiffener positions. Chapter (3) contains an account of a number of experimental investigations carried out on plates and girders with problems of stability relevant to the present problem. The various methods of examining these problems are also illustrated in Chapter (3).
The phenomena of plate buckling is discussed in Chapter (4) together with the various methods of measuring the buckling load. The physical changes caused by buckling which are used for the purpose of measuring the buckling load are discussed and the best possible arrangement of apparatus for performing the measurements are also suggested in this chapter. In Chapter ( 5) the procedure adopted for testing is discussed and the use of sane of the methods of measurement discussed in Chapter (4) are illustrated. Here also the aims and objects of the experiments are stated.
The results obtained from the experiments are discussed in Chapter (6). Discussion is first centred upon the results obtained from plates with double-sided horizontal stiffeners, starting with stiffeners at the fifth depth position and going on to stiffeners at mid-depth and those at the quarter depth. Later in this chapter the results from plates stiffened on one side only are surveyed in a general manner and this is followed by a comparison in behaviour between plates stiffened horizontally on both sides and those stiffened horizontally on one side only. The section on non-destructive tests is concluded with an examination of the effect of varying the rigidity of the double sided vertical stiffeners.
As a preface to the section of Chapter (6) devoted to tests to failure, a study was made of the deflection contours produced in two of the girders when under load. The purpose of these contour tests was to enable the positions of the buckle-crests to be pin pointed in order to fix strain gauges in the appropriate positions.
As a result of the contour plots, positions were fixed for the strain gauges for use during the failure tests and the layouts are shown at the beginning of the section of Chapter (6) on destructive tests. The results obtained from the strain gauges illustrated the development of the stresses and strains in the girder and allowed a study of the post buckled behaviour of the girders to be made.
The results obtained gave information on the behaviour of girders initially plane and girders which were subject to sane initial imperfections. These results threw some interesting light on the comparative behaviour of the girders in these two states.
|Date of Award||Sep 1959|