PROPOSAL OF AN INTERPOLATION FUNCTION BETWEEN THE COMPRESSIVE AND TENSILE MERIDIANS OF FAILURE AND YIELDING CONCRETE SURFACES BASED ON BEZIER CURVES

FOLINO, P; SMILOVICH, D.

PANACM 2015 1st Pan-American Congress on Computational Mechanics

CIMNE

Lugar: Barcelona; Año: 2015; p. 261 - 271

This paper is related with cohesive frictional materials like concrete. It is well known that failure and mechanical behaviour of such materials depend on all the three invariants, and therefore yielding and failure surfaces involving a circular deviatoric shape, neglecting the incidence of the third invariant, cannot accurately represent the main features observed in multiaxial experimental tests, particularly when low connementlevels and load scenarios leading to dierent Lode angles are considered.Several functions have been proposed in the literature to predict the deviatoric shape of the failure surface of cohesive frictional materials. Most of them present a lack of smoothness and therefore, are not convenient for numerical implementations. Other proposals, present a C1 continuity type leading to a deviatoric shape similar to a triangle with rounded corners. Nevertheless, the complexity involved in numerical approaches when one of these deviatoric functions is considered, usually discourages it application, particularly inthe case of non local continuum formulations like gradient based plasticity models and in multiscale approaches, enough complex even without considering a non circular deviatoric shape of the failure and yielding surfaces. In this paper the suitability of Bezier curves to represent an appropriate deviatoric shapeto be considered in the failure and yielding surfaces of concrete like materials is presented. A full derivation of a numerical approach aiming to obtain an interpolation function between the compressive and tensile meridians is reported. Finally, a critical discussion about the convenience or not of using these polynomials is addressed.