Effect of different boundary conditions in direct tensile tests: experimental results

摘要

The effects of the kinematic 'constraints' of a direct tensile test on the complete load-displacement response in tension of concrete specimens were examined from tests with imposed uniform displacement (fixed platens) and from experiments with free rotation rotating platens through a closed-loop testing system. Cylindrical specimens and prismatic specimens were considered. The tests were monitored with an interferometric strait measurement (electronic speckle pattern interferometry). A notable outcome of the experiments is that the fixed platens imposed a more uniform strain field with higher peak loads. Also the post-peak branch had a shape that depends on the boundary conditions under which the tests were performed.