scholarly journals Deformation and Failure of MXene Nanosheets

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1253 ◽  
Author(s):  
Daiva Zeleniakiene ◽  
Gediminas Monastyreckis ◽  
Andrey Aniskevich ◽  
Paulius Griskevicius
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Energy Release Rate ◽  
Mechanical Behavior ◽  
Energy Release ◽  
Release Rate ◽  
Interlaminar Shear Strength ◽  
Free Standing ◽  
Interlaminar Shear ◽  
Shear Energy

This work is aimed at the development of finite element models and prediction of the mechanical behavior of MXene nanosheets. Using LS-Dyna Explicit software, a finite element model was designed to simulate the nanoindentation process of a two-dimensional MXene Ti3C2Tz monolayer flake and to validate the material model. For the evaluation of the adhesive strength of the free-standing Ti3C2Tz-based film, the model comprised single-layered MXene nanosheets with a specific number of individual flakes, and the reverse engineering method with a curve fitting approach was used. The interlaminar shear strength, in-plane stiffness, and shear energy release rate of MXene film were predicted using this approach. The results of the sensitivity analysis showed that interlaminar shear strength and in-plane stiffness have the largest influence on the mechanical behavior of MXene film under tension, while the shear energy release rate mainly affects the interlaminar damage properties of nanosheets.

Calculating Energy Release Rate as a Function of Crack Length Using a Multiple-Step Crack Closure Technique in Tire Finite Element Models

2018 ◽  
Vol 46 (3) ◽  
pp. 130-152
Author(s):  
Dennis S. Kelliher
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Crack Length ◽  
Energy Release ◽  
Crack Closure ◽  
Release Rate ◽  
Fatigue Behavior ◽  
Three Dimensions ◽  
Quantitative Prediction ◽  
Closure Technique

ABSTRACT When performing predictive durability analyses on tires using finite element methods, it is generally recognized that energy release rate (ERR) is the best measure by which to characterize the fatigue behavior of rubber. By addressing actual cracks in a simulation geometry, ERR provides a more appropriate durability criterion than the strain energy density (SED) of geometries without cracks. If determined as a function of crack length and loading history, and augmented with material crack growth properties, ERR allows for a quantitative prediction of fatigue life. Complications arise, however, from extra steps required to implement the calculation of ERR within the analysis process. This article presents an overview and some details of a method to perform such analyses. The method involves a preprocessing step that automates the creation of a ribbon crack within an axisymmetric-geometry finite element model at a predetermined location. After inflating and expanding to three dimensions to fully load the tire against a surface, full ribbon sections of the crack are then incrementally closed through multiple solution steps, finally achieving complete closure. A postprocessing step is developed to determine ERR as a function of crack length from this enforced crack closure technique. This includes an innovative approach to calculating ERR as the crack length approaches zero.

Finite Element Modeling for Energy Release Rate in Human Cortical Bone

Volume 2 ◽  
2004 ◽  
Author(s):  
Saiphon Charoenphan ◽  
Apiwon Polchai
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Finite Element Modeling ◽  
Energy Release Rate ◽  
Cortical Bone ◽  
Energy Release ◽  
Crack Growth ◽  
Release Rate ◽  
Slow Crack Growth ◽  
Finite Element Models

The energy release rates in human cortical bone are investigated using a hybrid method of experimental and finite element modeling techniques. An explicit finite element analysis was implemented with an energy release rate calculation for evaluating this important fracture property of bones. Comparison of the critical value of the energy release rate, Gc, shows good agreement between the finite element models and analytical solutions. The Gc was found to be approximately 820–1150 J/m2 depending upon the samples. Specimen thickness appears to have little effect on the plane strain condition and pure mode I assumption. Therefore the energy release rate can be regarded as a material constant and geometry independent and can be determined with thinner specimens. In addition, the R curve resulting from the finite element models during slow crack growth shows slight ductility of the bone specimen that indicates an ability to resist crack propagation. Oscillations were found at the onset of the crack growth due to the nodal releasing application in the models. In this study light mass-proportional damping was used to suppress the noises. Although this techniques was found to be efficient for this slow crack growth simulation, other methods to continuously release nodes during the crack growth would be recommended for rapid crack propagation.

scholarly journals CHARACTERIZATIONS OF SIZE EFFECT AND OVERALL MECHANICAL BEHAVIOR OF NANOCRYSTALLINE METALS

2013 ◽  
Vol 05 (01) ◽  
pp. 1350004 ◽  
Author(s):  
LI CHEN ◽  
YUEGUANG WEI
Keyword(s):  
Grain Boundary ◽  
Energy Release Rate ◽  
Mechanical Behavior ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Mode ◽  
Gradient Plasticity ◽  
Cohesive Model ◽  
Critical Separation ◽  
Boundary Fracture

A systematical study of size effects and mechanical behaviors for the nanocrystalline (nc) metals is performed. The grain boundary fracture process is considered and described by the mixed-mode interface cohesive model. The grain material is characterized by the conventional theory of strain gradient plasticity. In the present investigation, the effects of five important parameters on the overall mechanical behavior are studied systematically, which include the grain size, critical separation strength, energy release rate of interface separation, mixity of separation strength, as well as the mixity of separation energy release rate. A finite element method (FEM) covering the above characteristics within the grain and on the grain boundary is developed. The present results show that the overall strength and ductility of the nc metals strongly depend on the grain boundary features described by the mixed-mode cohesive interface model, and there is a competition of deformation of grain boundary with that of grain interior.

Energy release rate for kinking crack using mixed finite element

2014 ◽  
Vol 50 (5) ◽  
pp. 665-677 ◽  
Author(s):  
Bouziane Salah ◽  
Bouzerd Hamoudi ◽  
Boulares Noureddine ◽  
Guenfoud Mohamed
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mixed Finite Element

scholarly journals Analytical Energy Release Rate of Interfacial Crack in Composite Laminates

2019 ◽  
Vol 37 (1) ◽  
pp. 137-142
Author(s):  
Weiling Zheng ◽  
Longxi Zheng
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Composite Laminates ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Beam Theory ◽  
Three Point Bending ◽  
The Right

In order to study whether the interfacial crack will grow or not in the composite laminates, the energy release rate of a crack in three-point bending model was obtained by using the Timoshenko beam theory and local generalized forces. The results of energy release rate were validated by the finite element results. The results indicate that the energy release rate of left crack tip is equal to that of the right crack tip when the crack before the crack goes cross the loading point; after the crack goes cross the loading point, the energy release rate of the left crack tip increases and then decreases gradually, while the energy release rate of right crack tip decreases first and increases later; the energy release rate of left crack tip is equal to that of the right crack tip again when the crack is symmetric with the loading point.

Efficient Computation of Strain Energy Release Rate in Crack Growth Simulation

1999 ◽  
Author(s):  
D. J. Chen
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Error Estimator ◽  
Efficient Computation

Abstract This paper utilizes an automated process to simplify the calculation of the strain energy release rate (SERR) during the crack propagation. The convergence of a finite element solution is achieved by adaptive re-meshing scheme with an error estimator of the linear strain triangular (LST) elements. As the desired mesh density is achieved, computation of the SERR using virtual crack closure technique (VCCT) can be obtained by using the static condensation scheme without re-analyzing the finite element models. Thus, the amount of computational and modeling time can be significantly reduced in the analysis of the crack propagation.

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