Session Details

13:30
Numerical fracture studies of ultra-high performance concrete under dynamic loading
Mohammad Reza Khosravani (University of Siegen), Carola Bilgen (University of Siegen), Kerstin Weinberg (University of Siegen)

Kurzfassung:
Ultra-high performance concrete (UHPC) is a new class of concrete material. In this contribution, split Hopkinson pressure bar (SHPB) is modified and utilized to conduct series of spalling tests. Dynamic elastic modulus and dynamic tensile strength of the studied UHPC sepcimens are determined. Furthermore, the spalling test is numerically simulated by MATLAB program. Within this context two numerical fracture methods are compared with respect to determination of main parameter like the tensile strength and the specific fracture energy. In order to determine the latter one an inverse analysis is applied. The achieved results showed good agreement between numerical simulations and experimental observations.

13:50
Modelling of the Mars® 300 armour steel under impact loadings
Teresa Fras (French-German Research Institute of Saint-Louis (ISL)), Faderl Norbert (French-German Research Institute of Saint-Louis (ISL)), Lach Erhardt (French-German Research Institute of Saint-Louis (ISL))

Kurzfassung:
Material and protective properties of the Mars® 300 steel are analyzed to understand the steel behavior under impact loadings. To validate the flow and fracture model (the Hosford-Coulomb model), a numerical simulation of the impact configuration is performed in which the striker and target are made of the Mars® 300 steel. As targets, plates perforated by an array of holes applied as passive add-on armors in combat vehicles - are considered.

14:10
Numerical and experimental ricochet investigation of a spin-stabilised projectile
Marina Seidl (French-German Research Institute of Saint-Louis (ISL)), Thomas Wolf (French-German Research Institute of Saint-Louis (ISL)), Rainer Nuesing (French-German Research Institute of Saint-Louis (ISL))

Kurzfassung:
Numerical simulations in LS-DYNA are used for a qualitative investigation, as measurement precision limits the determination of projectile nutation under oblique impact. The parabolic flight trajectory causes nutation in spin-stabilised projectiles. They rotate at an angle contained between the inertial axis and the relative velocity vector. Especially at the critical angle, where the projectile no longer penetrates but ricochets, influential parameters need to be determined.

14:30
Application of the Phase-field Method for Crack Approximation on a Split-Hopkinson-Pressure-Bar Experiment
Christian Steinke (Technische Universität Dresden), Michael Kaliske (Technische Universität Dresden)

Kurzfassung:
The numerical simulation of fracture in brittle material remains a challenging task, both with respect to the suitable approximation technique as well as to the appropriate calibration experiment. The phase-field method – a promising approach under ongoing development – is applied to the simulation of the complex behavior of a concrete specimen in a split-Hopkinson-pressure bar experiment focusing on the capabilities of the method to obtain realistic crack initiation, evolution and arrest.