Dynamic fracture of notched plain concrete beams: 3D finite element study

• 3D FE analysis of notched plain concrete beams under different impact velocities.
• Rate sensitive microplane model is used as a constitutive law for concrete.
• For impact velocity greater than 100 mm/s significant effect of inertia is observed.
• Rate dependent fracture energy cannot be obtained from reaction-displacement curve.
• Numerical model realistically predicts the behavior of notched beams under impact.

Notched plain concrete beams loaded by impact hammer are numerically studied. The numerical and experimental results are compared in terms of load-deflection response, rate dependent tensile strength and rate dependent fracture energy. Moreover, the effect of impact velocity on reaction, strain rate, crack opening rate and crack velocity is predicted numerically and compared with the experimental results. The numerical model realistically captures the experimentally observed behavior of the notched plain concrete beams under dynamic loads. It is pointed out that to evaluate the true rate dependent material properties, such as tensile strength and fracture energy, inertia have to be filtered out otherwise for higher strain rates the material properties are significantly overestimated.