Cracking of quasi-brittle structures under monotonic and cyclic loadings: A d+/d− damage model with stiffness recovery in shear

Autor: Giulio Ventura, Claudia Tesei, Miguel Cervera
Přispěvatelé: Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. RMEE - Grup de Resistència de Materials i Estructures en l'Enginyeria
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Cracking
Constitutive equation
Modulus
Enginyeria civil::Materials i estructures [Àrees temàtiques de la UPC]
02 engineering and technology
01 natural sciences
Crack closure
0203 mechanical engineering
General Materials Science
Masonry structures
Composite material
Estructures de murs -- Models matemàtics
Applied Mathematics
Stiffness
Dissipation
Condensed Matter Physics
Formigó -- Fissuració -- Models matemàtics
Strength of materials
Masonry--Testing
010101 applied mathematics
Engineering
Mechanical
020303 mechanical engineering & transports
Damage
Mechanics of Materials
Modeling and Simulation
Materials Science (all)
Concrete structures
medicine.symptom
Microcrack closure-reopening effects
Engineering
Civil
Materials science
Engineering
Multidisciplinary
Cyclic loading
Damage-induced orthotropy
Energy-equivalence
Numerical robustness
Spectral decomposition
Mechanical Engineering
Brittleness
medicine
Engineering
Ocean
0101 mathematics
Engineering
Aerospace
Engineering
Biomedical
Infinitesimal strain theory
Computer Science
Software Engineering
Engineering
Marine
Engineering
Manufacturing
Engineering
Industrial
Concrete--Cracking--Mathematical models
Zdroj: Scipedia Open Access
Scipedia SL
UPCommons. Portal del coneixement obert de la UPC
Universitat Politècnica de Catalunya (UPC)
Recercat. Dipósit de la Recerca de Catalunya
instname
Popis: In the present paper, a newd+/d−damage model apt forquasi-brittle materialsis described and its validation is carried out considering unreinforced concrete,reinforced concreteand masonry elements. Two independent scalar damage variables,d+andd−, in combination with the split of the reversiblestrain tensorinto its positive and negative counterparts, are adopted in order to simulate the pronounced dissimilar response under tension and compression, typical of these materials. An energy-equivalent framework is considered for representing the orthotropy induced in the material by thedegradation process, with the consequence that a thermodynamically consistent constitutive operator,positive definite, symmetricand strain-driven, is derived. In addition to the degradation parameters, the permanent strain tensor is also contemplated by the model and a modification of theexponential softening modulus is proposed in order to treat the evolution of the two causes of dissipation, damage andirreversible deformations, in a coupled way. The formulation is integrated with a multidirectional damage procedure, addressed to extend themicrocrackclosure-reopening (MCR) capabilities of the model to shear cyclic conditions, characterized by orthogonal (or however intersecting) sets of cracks. Maintaining unaltered the dependence of theconstitutive lawfrom two scalar indeces,d+andd−, this approach activates or deactivates atensile(compressive) damage value on the base of the current maximum (minimum)principal straindirection. In correspondence with damage activation (crack opening) ordeactivation(crack closure), a smooth transition is introduced, in order to avoidabrupt changesin stiffness and enhance the numerical performance and robustness of the multidirectional procedure. The adequacy of the proposedconstitutive modelin reproducingexperimental resultshas been proven for both monotonic andcyclic loading conditions. The two examples of application involvingcyclic loads, dominated by shear, constitute a validation of the multidirectional damage approach, showing how the suitable representation of unilateral effects andpermanent deformationsis essential to model the observed structural response in terms of maximum resistance, evolution ofstiffness degradationand dissipation capacity.
Databáze: OpenAIRE
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