Inhomogeneity effects on the crack driving force in elastic and elastic–plastic materials

The goal of this paper is to derive a micromechanics framework to study the kinetics of transformation due to interface migration in elastic-plastic materials. Both coherent and incoherent interfaces as well as interstitial and substitutional atomic diffusion are considered, and diffusional transformations are contrasted with martensitic ones. Assuming the same dissipation for the rearrangement of all substitutional components and no dissipation due to diffusion in an interface in the case of a multicomponent diffusional transformation, we show that the chemical driving force of the interface motion is represented by the jump in the chemical potential of the lattice forming constituent. Next, the mechanical driving force is shown to have the same form for both coherent and frictionless (sliding) interfaces in an elastic-plastic material. Using micromechanics arguments we show that the dissipation and consequently the average mechanical driving force at the interface due to transformation in a microregion can be estimated in terms of the bulk fields. By combining the chemical and mechanical parts, we obtain the kinetic equation for the volume fraction of the transformed phase due to a multicomponent diffusional transformation. Finally, the communication between individual microregions and the macroscale is expressed by proper parameters and initial as well as boundary conditions. This concept can be implemented into standard frameworks of computational mechanics.

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The Configurational Force Concept in Elastic-Plastic Fracture Mechanics−Instructive Examples

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.417-418.297 ◽

2009 ◽

Vol 417-418 ◽

pp. 297-300 ◽

Cited By ~ 3

Author(s):

R. Schöngrundner ◽

Otmar Kolednik ◽

Franz Dieter Fischer

Keyword(s):

Driving Force ◽

Plastic Material ◽

Shielding Effect ◽

Integral Approach ◽

J Integral ◽

Configurational Force ◽

Crack Driving Force ◽

Elastic Plastic ◽

Elastic Plastic Material ◽

Elastic Plastic Materials

This paper deals with the determination of the crack driving force in elastic-plastic materials and its correlation with the J-Integral approach. In a real elastic-plastic material, the conventional J-integral cannot describe the crack driving force. This problem has been solved in Simha et al. [1], where the configurational force approach was used to evaluate in a new way the J-integral under incremental plasticity conditions. The crack driving force in a homogeneous elastic-plastic material, Jtip, is given by the sum of the nominally applied far-field crack driving force, Jfar, and the plasticity influence term, Cp, which accounts for the shielding or anti-shielding effect of plasticity. In this study, the incremental plasticity J-integral and the crack driving force are considered for a stationary and a growing crack.

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Numerical Assessments of Cracks in Elastic-Plastic Materials

10.1007/978-3-540-45882-1 ◽

2002 ◽

Cited By ~ 3

Author(s):

Huang Yuan

Keyword(s):

Elastic Plastic ◽

Plastic Materials ◽

Elastic Plastic Materials

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A pressurized blister test model for the interface adhesion of dissimilar elastic–plastic materials

Materials Science and Engineering A ◽

10.1016/j.msea.2007.10.014 ◽

2008 ◽

Vol 487 (1-2) ◽

pp. 228-234 ◽

Cited By ~ 12

Author(s):

L.M. Jiang ◽

Y.C. Zhou ◽

Y.G. Liao ◽

C.Q. Sun

Keyword(s):

Test Model ◽

Interface Adhesion ◽

Blister Test ◽

Elastic Plastic ◽

Plastic Materials ◽

Elastic Plastic Materials

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On Determining Elastic Modulus from Instrumented Indentation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.668.616 ◽

2013 ◽

Vol 668 ◽

pp. 616-620

Author(s):

Shuai Huang ◽

Huang Yuan

Keyword(s):

Finite Element ◽

Elastic Modulus ◽

Plastic Material ◽

Instrumented Indentation ◽

Computational Simulations ◽

Elastic Plastic ◽

Modified Method ◽

Plastic Materials ◽

Elastic Plastic Material ◽

Elastic Plastic Materials

Computational simulations of indentations in elastic-plastic materials showed overestimate in determining elastic modulus using the Oliver & Pharr’s method. Deviations significantly increase with decreasing material hardening. Based on extensive finite element computations the correlation between elastic-plastic material property and indentation has been carried out. A modified method was introduced for estimating elastic modulus from dimensional analysis associated with indentation data. Experimental verifications confirm that the new method produces more accurate prediction of elastic modulus than the Oliver & Pharr’s method.

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