Lateral buckling tests on monosymmetric plate girders

A series of tests on laterally unrestrained, welded, unequal flange girders is described. Attention is given to the careful design and fabrication of the test girders so as to ensure a proper representation of full-scale bridge girders, including the presence of controlled and realistic levels of imperfection. The ways in which the specially designed test apparatus met the need for clearly identifiable boundary conditions are discussed in some detail. A preliminary presentation and discussion of the test results is included; this confirms that welded, monosymmetric beams (whose larger flanges are in tension) possess lower lateral buckling strengths than either rolled sections or equal flange welded sections.