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High order isogeometric cohesive elements for delamination analysis

Please find attached two recent papers on the use of high order B-splines/NURBS cohesive interface elements for an efficient modeling of delamination of composite laminates.  

Debonding simulation - XFEM fracture criterion - delamination

Hello

I am using Abaqus/CAE 6.10 to simulate a Debonding test (cohesive behavior for composite delamination). 

I ran a Abaqus debonding simulation example (from Abaqus online documentation - Abaqus Benchmark Manual - 2.7.1 Delamination analysis of laminated composites).

The Abaqus/Explicit three-dimensional model with surface-based traction-separation behavior used a surface contact interaction property with:

- default Cohesive behavior

- XFEM-based LEFM (using VCCT) fracture criterion.

DCB test - CONTINUUM SHELL ELEMENTS vs SOLID ELEMENTS

Hello,

I modelled a 3-D DCB (Double Cantilever Beam) test specimen to simulate crack propagation (delamination) in composite materials.

To do so, I used surface cohesive properties between plates in Abaqus/Explicit, and applied a displacement at the plates tips.

When I used continuum shell elements the crack propagated as expected and the delamination occurred.

Cohesive Analysis with Abaqus/Explicit

Hello all,

I'm trying to model composite delamination under non-severe impact on layered composites in ABAQUS/Explicit.

To begin with, I've modeled a 2D aluminum with a finite very low thickness cohesive layer with traction-separation behavior between. Then, I give some displacement to the middle-top node to simulate an impact scenario. However, even in this simple configuration, I'm having stress distribution problems when the models with cohesive layer between and without cohesive layer are compared.

How to plot Fracture toughness vs Crack length in Abaqus for Delamination problem

I've modelled a DCB specimen and applied Boundary conditions and load... I followed the same procedures given in abaqus documentation... As expected the crack initiates and propagates along the interface... I can get the Resultant force vs displacement plot from the analysis.. But i dont know how to plot the fracture toughness vs crack length plot in ABAQUS..

Please help me... Your suggestion would really help me a lot..

Simulation of composite delamination caused by impact

Hi All,

While using LS-DYNA to simulate the impact damage of composites, I have a question about modeling.

I plan to create the model by solid element. Each ply has one element in the thickness direction. The contact between plies is *contact_automatic_surface_to_surface_tiebreak. My question is how to create separate ply models while using this contact. It is clear that common nodes are not allowed. So there might be two possibilities.

hasanzhong's picture

Finite Element Analysis of the Indentation-Induced Delamination of Bi-Layer Structures

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University of Southern California
IP : 132.174.255.3
Sun, 29 Jul 2012 00:05:58
Contact deformation can cause local damage of mechanical structures and lead to structural failure
of mechanical devices. In this work, we use the finite element method to analyze the indentation-
induced delamination of a film-substrate structure and the critical tensile stress as the criterion to
determine local delamination on the interface between the film and the substrate. The simulation

Solver settings in Abaqus/S for delamination analysis with cohesive elements

Choose a channel featured in the header of iMechanica: 

Hi 
 
I have different 3D models of laminates where I analyse the delamination propagation using zero thickness cohesive elements in Abaqus/Standard. My experience with the RIKS solver and Newton solvers are that they are extremely sensitive to even small changes in the step size settings as well as other solver settings. 

How to model delamination in laminated composites?

Hi,

  I'm Praveen doing my Master of Technology Project. I wanted to know how to model delaminated composites in ANSYS. Whether to use Teflon layer as delamination between the plies or creating air gap between the plies? And also wanted to know how to use cohesive zone elements or interface elements to create delamination. Can anyone help me? I ve attached images for references. 

A free program to generate interface elements in an existing FE mesh

Hello all,

Last year when I started implementing interface elements to model material failure, I realized that the formulation is easy except how to generate a mesh with interface elements. I did a googling to search for such a free program. Amazingly, I did not find any although there are many researchers working on the fracture mechanics field.

So, I wrote a small object-oriented C++ program which reads a FE mesh, duplicates nodes and insert interface elements where asked. The program is able to

(1) insert 1D/2D interface elements everywhere in a FE mesh

Hirschberger's picture

1st MUSIC Summer School on "Multiscale and Multiphysics Modelling of Interfaces"

The Graduate School MUSIC (Multiscale Methods for Interface Coupling) invites to its first Summer School on Multiscale and Multiphysics Modelling of Interfaces at Leibniz Universitaet Hannover, Germany, from 15 to 17 September 2010.

Venkat Bharath's picture

Cohesive behaviour for Interaction in Abaqus Explicit at the interface of materials

Hi,
I am working on effects of Blast Loading in sandwich composites using Abaqus. I want to incorporate Cohesive behaviour at the interface of the two materials in the sandwich composite structure i am analysing.

Delaminated Composite Plate

Choose a channel featured in the header of iMechanica: 

 Hi,

 I am researching delaminated composite plates.

 How can i model the delamination area in two plies, is abaqus a correct choice for modelling?

 Delamination area is rectangular or circular.

 Regards.

 

Help needed in defining Gap Elements in Abaqus

Hi

I want to know how we can define a Gap Element In ABAQUS

I am doing a research about simulating a delaminated plate by FE Gap Elements

 Please Help

Thanks an advance

Etienne Barthel's picture

Buckling

Taxonomy upgrade extras: 
Rui Huang's picture

Influence of Interfacial Delamination on Channel Cracking of Brittle Thin Films


H. Mei, Y. Pang, and R. Huang, International Journal of Fracture 148, 331-342 (2007).

Following a previous effort published in MRS Proceedings, we wrote a journal article of the same title, with more numerical results. While the main conclusions stay the same, a few subtle points are noted in this paper.

Chip-package interaction and interfacial delamination

In flip-chip package, the mismatch of thermal expansion coefficients between the silicon die and packaging substrate induces concentrated stress field around the edges and corners of silicon die during assembly, testing and services. The concentrated stresses result in delamination on many interfaces on several levels of structures, in various length scales from tens of nanometers to hundreds of micrometers. A major challenge to model flip-chip packages is the huge variation of length scales, the complexity of microstructures, and diverse materials properties. In this paper, we simplify the structure to be silicon/substrate with wedge configuration, and neglect the small local features of integrated circuits. This macroscopic analysis on package level is generic with whatever small local features, as long as the physical processes of interest occur in the region where the concentrated stress field due to chip-packaging interaction dominates. Because it is the same driving force that motivates all of the flaws. Therefore, the different interface cracks with same size and same orientation but on different interfaces should have similar energy release rates provided that the cracks are much smaller than the macroscopic length. We calculate the energy release rate and the mode angle of crack on the chip-package interface based on the asymptotic linear elastic stress field. In a large range of crack length, the asymptotic solution agrees with finite element calculation very well. We discuss the simplified model and results in context of real applications. In addition, we find that the relation of energy release rate G and crack length a is not power-law since local mode mixity is dependent of crack length a. Therefore, the curve of G~a can be wavy and hardly goes to zero even if crack length a goes to atomically small. The local mode mixity plays an important role in crack behavior.

Nanshu Lu's picture

Delamination of stiff islands patterned on stretchable substrates

As another celebration of March Journal Club of Mechanics of Flexible Electronics, this paper has just been submitted.

Abstract 

In one design of flexible electronics, thin-film islands of a stiff material are fabricated on a polymeric substrate, and functional materials are grown on these islands. When the substrate is stretched, the deformation is mainly accommodated by the substrate, and the islands and functional materials experience relatively small strains. Experiments have shown that, however, for a given amount of stretch, the islands exceeding a certain size may delaminate from the substrate. We calculate the energy release rate using a combination of finite element method and complex variable method. Our results show that the energy release rate diminishes as the island size or substrate stiffness decreases. Consequently, the critical island size is large when the substrate is compliant. We also obtain an analytical expression for the energy release rate of debonding islands from a very compliant substrate.

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