Influence Of Static Characteristics, The Cracks Of Beam Structure

This thesis firstly classified bridge cracks and analyzed their causes. Then theindoor model tests were conducted for4pieces of simply supported organic glass Tbeams and one piece of reinforced concrete rectangular beam. The test results werecompared with the ones obtained from the Ansys finite element model with theemphasis on influence of crack on bottom strain distribution of the beams. On thebasis of model tests, the influence of the cracks on the static character of commonlyused small and middle-span simply supported beams were numerically studied, withthe following conclusions obtained:①Applying separate crack model with ANSYS for modeling cracks in simplysupported beams is reasonable and is able to accurately capture their staticcharacteristics;②Under a concentrated load, a large strain gradient exists in the area near thecrack. The strain at the crack location is close to zero and rapidly changes to itsnormal value away from the crack;③Ideally, the size of the crack influence zone on strain is independent of thestatic load imposed;④Beam deflection difference before and after the occurrence of cracks cannotserve as an effective parameter of the possible crack position indicator;⑤Ideally, the size of the strain influence zone of a crack is independent of thespan of the T beams;⑥The influence of longitudinal cracks on axial strain distribution of simplysupported hollow slab beams is negligible.⑦The transverse strain distribution of a simply supported hollow slab beam isonly dependent on the depth of longitudinal cracks and independent of their length.