Computational modeling of fiber reinforced brittle materials

• Grant number: 12/05430-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 01, 2012
• End date: August 31, 2013
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: Tulio Nogueira Bittencourt
• Grantee: Luís Antônio Guimarães Bitencourt Júnior
• Supervisor: Frank J. Vecchio
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Toronto (U of T), Canada
• Associated to the scholarship: 09/07451-2 - Numerical modeling of failure processes in steel fiber reinforced cementitious materials, BP.DR

Abstract

This project proposes the development of the new techniques for modeling reinforced concrete structures. Steel fibers, disperse in the matrix, can be considered. This technique involves the mixture theory methodology; standard finite element with a very high aspect ratio; continuous strong discontinuity approach; embedded discontinuity technique and accelerated schemes for the solution of non-linear finite element equations. Truss finite elements with elastoplastic constitutive models will be used to represent fibers and reinforced bars. Standard finite elements with a very high aspect ratio will be used to model the behavior of the interfaces between distinct components of the composite. These elements present the same kinematics as the Continuous Strong Discontinuity Approach (CSDA) and can be used to describe bond stress between components, even when the thickness of the interface region tends to zero. Some scalar damage models, consistent with the CSDA, will be investigated to describe bond degradation due to slip. Special compatibility finite elements will be developed to connect the nodes of the interface elements to an arbitrary concrete mesh, providing a kind of embedded representation of fibers or reinforcing bars suitable for the modeling of very complex reinforcement layouts. The brittle behavior of the concrete matrix will be represented by a continuum damage constitutive model and the formation and propagation of cracks are modeled by means of the embedded discontinuity technique. To increase the computability of the analysis, an accelerated schemes based an implicit/explicit integration scheme will be developed for the solution of non-linear finite element equations. The program that will be developed will be validated with an extensive comparison with experimental results for demonstrate the effectiveness of the proposed technique. Initially the numerical simulation of basic tests such as pullout, tension and compression will be performed and finally simulations of more complex structural elements will be made. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BITENCOURT JR, LUIS A. G.; MANZOLI, OSVALDO L.; BITTENCOURT, TULIO N.; VECCHIO, FRANK J.. Numerical modeling of steel fiber reinforced concrete with a discrete and explicit representation of steel fibers. INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, v. 159, p. 171-190, MAR 2019. (12/05430-0, 09/07451-2)

BITENCOURT, JR., LUIS A. G.; MANZOLI, OSVALDO L.; TRINDADE, YASMIN T.; RODRIGUES, EDUARDO A.; DIAS-DA-COSTA, DANIEL. Modeling reinforced concrete structures using coupling finite elements for discrete representation of reinforcements. FINITE ELEMENTS IN ANALYSIS AND DESIGN, v. 149, p. 32-44, SEP 15 2018. (12/05430-0, 09/07451-2)