Numerical Study of Failure of Cementitious Composite Specimens in Modified Compact Tension Fracture Test

Modified compact tension specimen for experiments on cement based materials: comparison of calibration curves from 2D and 3D numerical solutions

“…The calibration curves are introduced in Eqs. (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) for each selected case. …”

“…However, its applicability in concrete is characterized by some disadvantages, such as drilling the holes necessary to apply C the pulling forces and the hazard of a local fracture originated at these holes. The modified compact tension test (MCT [4,5,9,10,21,23) is a quite new test configuration on notched specimens to obtain fracture mechanics parameters of materials in laboratory conditions, note that test is derived from classic CT test. A detailed research program/campaign has to be done before the configuration starts to be used as a standard.…”

Quantification of Influence of Epoxy Layer Between Interface Steel-Concrete on Calibration Curves for Modified Compact Tension Test

“…And this is both with the creation of the openings (for input of the load device pins) and then with the actual loading of the specimens. During numerical simulations of the CT specimen [28] it has been found that failure occurs in the specimen at the contact of the opening and the pin imposing the load. Because of this reason, alternative ways, how to apply the tensile load to reach failure initiated exclusively from the notch, were sought.…”

“…An experimental campaign on sets of these modified specimens is under preparation in the laboratory at University of Sevilla. This contribution follows on and extends information given in [28], where numerical analysis of failure process (software ATENA with the cohesive crack modelling was used [7]) in specimens for this test configuration was done. The contribution also follows numerical calculations of calibration curves published in [22], where the interface of concrete/steel E c = 40 GPa, E s = 210 GPa is introduced, then the pilot study of concrete/steel interface influence (for E c varied from 5 to 50 GPa) published in [23].…”

“…The possible inaccuracy caused by material interface of calibration curves is discussed. Fig.1: Studied configurations of ModCT test with glued loading plates and dog-bone shaped specimens with various position of load P (causes the change of the stress field in direction of the propagating crack), adopted from [28].…”