000021702 001__ 21702
000021702 005__ 20170622131300.0
000021702 04107 $$aeng
000021702 046__ $$k2017-06-15
000021702 100__ $$aKvětoň, Josef
000021702 24500 $$aSIMULATIONS OF CONCRETE FRACTURE AT VARIOUS STRAIN RATES: PARAMETRIC STUDY

000021702 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000021702 260__ $$bNational Technical University of Athens, 2017
000021702 506__ $$arestricted
000021702 520__ $$2eng$$aThe contribution presents numerical simulations of a recently published experimental series on concrete specimens. The numerical model mimics the meso-structure of the concrete by representing material via system of interconnected rigid polyhedral particles. These particles correspond to mineral aggregates and surrounding matrix. The geometry of particles is based on Voronoi tessellation. The particles are rigid, but they may move and rotate. The displacement jump at their contacts gives rise interaction forces defined by the constitutive relation in a vectorial form. The constitutive equations are independent of the strain rate. Simulations are dynamical, the time dependent response is calculated using Newmark implicit scheme. Full inertia tensor of every particle is taken into account when assembling the mass matrix. To demonstrate the ability of the model to capture the strain rate dependence of the experimental results, series of specimens loaded under various displacement rates are simulated. For quasi-static loading, the initial microcracks usually localize into one highly damaged zone where main crack appears. With increasing strain rate, the amount of energy accumulated in the specimen body is not consumed by one crack only and crack branching occurs. The peak loading force increases with increasing rate as well. Both the strain rate dependence of the loading force and crack branching phenomena are captured by the presented numerical model. The obtained results are compared with the experimental response of the simulated specimens. Parametric study of the model is performed showing different effect of various parameters under different strain rates.

000021702 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000021702 653__ $$aDiscrete model, Concrete fracture, Dynamics, Inertia, Strain Rate

000021702 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000021702 720__ $$aKvětoň, Josef$$iEliáš, Jan
000021702 8560_ $$ffischerc@itam.cas.cz
000021702 8564_ $$s1036064$$uhttps://invenio.itam.cas.cz/record/21702/files/17557.pdf$$yOriginal version of the author's contribution as presented on CD, section: [RS30] Concrete structural members
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000021702 962__ $$r21500
000021702 980__ $$aPAPER