Cohesive interfacial crack analysis of concrete materials and reinforced concrete structures.

摘要

The objective of computational failure analysis is to avoid the mesh sensitivity and size dependency in global analyses for both continuum and discrete approaches. In this thesis, the discrete approach using zero-thickness interface element will be emphasized to investigate these main two objectives. To this end, a sophisticate finite element simulation platform FEM-C++. 1 will be used for the main analyses. The line and surface interface elements are implemented with a simple traction-jump softening law in order to account for material nonlinearities in 2D and 3D respectively. A few benchmark problems of plain concrete and reinforced concrete structures are analyzed to calibrate and examine the shear interaction ratio alpha and their influence to complex mixed mode stress states.; The degradation of interface transition zones in heterogeneous materials due to thermal and mechanical damage is also examined. The interaction of normal and tangential damage at the interface level and the interaction of thermal and mechanical damage when thermal softening is coupled with mechanical degradation are addressed with the example of a ends-constrained heterogeneous RVE of concrete in 2D.; Finally, the global and local behavior of a five-story lightly reinforced concrete shear-wall structure subjected to seismic loading in two directions on a shake table are examined. Results of the shake table tests conducted under CAMUS 2000--1 are used as a reference to assess the performance of carriage and elasto-plastic finite element simulations in the time domain.; 1A Object-Oriented Program for Finite Element Modeling, Aerospace Engineering Sciences, University of Colorado at Boulder.