A damage model for granite subjected to quasi-static contact loading

• An anisotropic damage model is employed in order to simulate the fracture pattern of Bohus granite under quasi-static (Q-S) spherical indentation loading. The chosen damage description is added to the previously employed Drucker–Prager (DP) plasticity model with variable dilation angle. The resulting constitutive model is implemented to simulate the behavior of Bohus granite under indentation up to the load capacity of the material. The initial fragmentation, corresponding to the first small load-drop in the force–penetration curve, is likely due to the high radial tensile stress state at or close to the contact boundary. Both predicted fracture pattern and force–penetration results from the numerical simulation are compared to experimental data and a good agreement is found. The variability in tensile strength of the material is included in the chosen damage model by taking advantage of Weibull statistics. In this work, it is suggested that indentation test results by themselves may be used to calibrate the statistical distribution of tensile strength at small size scales such as in indentation applications. 

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Naturresursteknik -- Geofysisk teknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Engineering -- Geophysical Engineering (hsv//eng)

Keyword

Indentation

Tensile strength

Weibull distribution

Anisotropic damage model

Contact loading

Damage

Damage modelling

Effective volume

Fracture pattern

Inelastic behavior

Quasi-static

Quasi-static contacts

Quasi-static indentation

Granite

constitutive equation

damage mechanics

dilation

experimental study

loading

numerical method

rock mechanics

Publication and Content Type

ref (subject category)

art (subject category)