COBEM99

S24 Mecânica dos Sólidos

Title:

IMPLEMENTATION OF THE MAXWELL VISCOELASTIC MODEL WITH AGING FOR TRIDIMENSIONAL PROBLEMS

Summary :

ABSTRACT. A GREAT CLASS OF MATERIALS WITH TIME AND/OR FREQUENCY DEPENDENT PROPERTIES CAN BE DESCRIBED BY THE GENERALIZED MAXWELL CHAIN MODEL. EXAMPLES OF THAT ARE POLYMERIC MATERIALS AND MASS CONCRETE, USUALLY USED IN ENGINEERING. THE NUMERICAL MODEL BASED ON THE DIFFERENTIAL FORMULATION REPRESENTS A COMPUTATIONAL IMPROVEMENT COMPARED TO OTHER MODELS FOR THE SIMULATION OF REOLOGIC PROBLEMS. FACE TO THE LARGE NUMBER OF VARIABLES ("HIDDEN STRESSES" OF THE MAXWELL CHAIN) THAT NEEDS TO BE TREATED IN EACH STEP, THE EFFICIENCY FOR TRIDIMENSIONAL ANALYSIS CAN BE PROBLEMATIC. IN ORDER TO AVOID THAT PROBLEM, THE USE OF A SOLID TRILINEAR FINITE ELEMENT IS PROPOSED, IN WHICH THE INTERNAL FORCES ARE INTEGRATED BY ONE GAUSS POINT, RESULTING IN A REDUCED WASTE OF MEMORY TO SAVE THE STRESS VALUES AND ALSO RESULTING IN A COMPLETELY VECTORIZED ROUTINE. THE ELEMENT IS FORMULATED TO PRESENT THE LINEAR VISCOELASTIC BEHAVIOR OF AN ISOTROPIC MATERIAL CONSIDERING THE AGING OF ITS PROPERTIES. KEYWORDS: VISCOELASTICITY, FINITE ELEMENTS, REDUCED INTEGRATION.

Author :

Coutinho, Alvaro L. G. A.
Fairbairn, Eduardo M. R.
Viana, Dianne Magalhães

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