Print Email Facebook Twitter Nonlocal Damage Models for Concrete Title Nonlocal Damage Models for Concrete Author Maravalalu Suresh, R.S. Contributor Sluys, L.J. (mentor) Weerheijm, J. (mentor) Khoe, Y.S. (mentor) Faculty Civil Engineering and Geosciences Department Structural Engineering Programme Structural Mechanics Date 2013-11-08 Abstract An understanding of response of concrete structures to impact loading is of interest to the Explosions, Ballistics and Protection department of TNO. Numerical simulations conducted to study this response require very small elements to capture the shockwave propagation and the material response which were found to be mesh dependent. The goal of the thesis is to implement and investigate a nonlocal model to obtain mesh independent results when simulating concrete failure under dynamic loads. The nonlocal models are implemented in LS-DYNA by modifying the user subroutines. The original nonlocal model has certain drawbacks which are investigated by means of certain benchmark tests. The use of the constant length scale and the isotropic weight function is found to be the cause of the drawbacks of the nonlocal model. A modified nonlocal model, the Stress based nonlocal model which resolves the issues of the original nonlocal model is implemented. The stress based nonlocal model is investigated to understand its behavior which leads to the resolution of the drawbacks of the nonlocal model. The stress based nonlocal model provides physically relevant fracture processes. The behavior of the model in a dynamic loading at various loading rates is investigated in comparison to the quasi-static loading. It is found that the model cannot capture the varying fracture processes zone widths as expected with the varying loading rates. The stress based nonlocal model is finally validated with experimental results and mesh independent results are obtained. The model cannot capture the varying fracture processes with different loading rates as seen in experiments. This is due to the use of the rate independent material model in combination with the stress based nonlocal model behavior. Subject damage mechanicsnonlocalconcretemesh sensitivity To reference this document use: http://resolver.tudelft.nl/uuid:39a672a4-a554-4a1e-97da-7bc613b40cf1 Part of collection Student theses Document type master thesis Rights (c) 2013 Maravalalu Suresh, R.S. Files PDF Thesis_-_Nonlocal_Damage_ ... Suresh.pdf 4.65 MB Close viewer /islandora/object/uuid:39a672a4-a554-4a1e-97da-7bc613b40cf1/datastream/OBJ/view