FATIGUE TESTS OF HYBRID PLATE GIRDERS UNDER COMBINED BENDING AND SHEAR

THREE HYBRID PLATE GIRDERS WERE TESTED IN COMBINED BENDING AND SHEAR. BOTH FATIGUE AND STATIC ULTIMATE TESTS WERE PERFORMED. THE FLANGES WERE OF A514 STEEL AND THE WEBS WERE OF A36 STEEL. THE STRESS RANGE IN THE FLANGES WAS 25 KSI WITH THE FLANGE STRESS FLUCTUATING FROM 25 KSI TO 50 KSI. THE ONLY VARIABLE WAS THE TRANSVERSE STIFFENER LENGTH. FROM THE TESTS IT IS CONCLUDED THAT THE U-SHAPED CRACKS THAT FORMED UNDER THE STIFFENERS IN ONE GIRDER WERE NOT FATAL AND THAT HYBRID PLATE GIRDERS UNDER COMBINED BENDING AND SHEAR HAVE A SHORTER FATIGUE LIFE THAN THE SAME GIRDERS UNDER PURE BENDING. FROM THE STATIC ULTIMATE TESTS IT IS CONCLUDED THAT BASLER'S TENSION FIELD THEORY CAN BE USED TO PREDICT THE ULTIMATE LOAD OF HYBRID PLATE GIRDERS UNDER COMBINED BENDING AND SHEAR. /AUTHOR/