Numerical modeling of a beam with a hole for verification of the tensile strength

• Main Authors: Marcalikova, Zuzana, Cajka, Radim
• Format: Conference Proceeding
• Language: English
• Subjects: Axial stress; Bend tests; Fiber reinforced concretes; Mathematical models; Numerical models; Tensile strength; Tensile stress
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0081663

The paper deals with numerical modeling simulating bending tests of fiber-reinforced concrete beams. Two variants of the beam measuring 150 x 150 x 700 mm were made. It was a variant of a beam with a hole in the middle and a beam without a hole. The study assumed that the tensile stress at the place above/below the hole is uniform and can be considered very close to axial tensile stress. Based on the four-point bending test and the force at the boundary of the first cracks, the stress in the lower fibers of the beam with a hole and without a hole was determined. The stress sizes in the lower fibers were subsequently verified by numerical models. Numerical models were performed in a variant solution, which differed in the size of the finite elements (10 and 30 mm) and the location of the supports (in the axis of the beam, on the lower edge of the beam). This numerical study verified the uniformity of the stress and therefore the magnitude of this stress can be considered as the tensile strength. The great advantage of the tensile strength determined in this way is the low complexity of testing because the principle of the test (specimen size, arrangement during the test) was maintained as in case of the standard tests. The advantage is also in determining tensile strength, which is directly based on the test results, without the use of a conversion function what is necessary in case of other bending tests.