Multi-scale failure analysis of plain-woven composites

2012 ◽  
Vol 47 (6) ◽  
pp. 379-388 ◽  
Author(s):  
Omar Bacarreza ◽  
MH Aliabadi ◽  
Alfonso Apicella
Keyword(s):  
Damage Mechanics ◽  
Effective Properties ◽  
Progressive Failure ◽  
Continuum Damage Mechanics ◽  
Internal Variable ◽  
Homogenization Method ◽  
Woven Composites ◽  
Computationally Efficient ◽  
Efficient Manner ◽  
Multi Scale

A numerical model capable of dealing with progressive degradation of plain woven composites in a computationally efficient manner is presented in this article. A semi-analytical homogenization method is used to derive effective properties of the composite from the material properties of the constituents. The progressive failure is described using nonlocal continuum damage mechanics where the driving internal variable for the damage is the nonlocal strain. The model was implemented into Abaqus/Explicit, where the failure of a longitudinal tension and an open hole tension specimens were simulated in a multi-scale manner and verified experimentally.

Cross-Ply Laminates under Static Three-Point Bending: A Numerical Development Model

2012 ◽  
Vol 498 ◽  
pp. 42-54 ◽  
Author(s):  
S. Benbelaid ◽  
B. Bezzazi ◽  
A. Bezazi
Keyword(s):  
Numerical Model ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Failure Criteria ◽  
Continuum Damage ◽  
Damage Development ◽  
Element Analysis ◽  
Progressive Failure Analysis

This paper considers damage development mechanisms in cross-ply laminates using an accurate numerical model. Under static three points bending, two modes of damage progression in cross-ply laminates are predominated: transverse cracking and delamination. However, this second mode of damage is not accounted in our numerical model. After a general review of experimental approaches of observed behavior of laminates, the focus is laid on predicting laminate behavior based on continuum damage mechanics. In this study, a continuum damage model based on ply failure criteria is presented, which is initially proposed by Ladevèze. To reveal the effect of different stacking sequence of the laminate; such as thickness and the interior or exterior disposition of the 0° and 90° oriented layers in the laminate, an equivalent damage accumulation which cover all ply failure mechanisms has been predicted. However, the solution algorithm using finite element analysis which implements progressive failure analysis is summarized. The results of the numerical computation have been justified by the previous published experimental observations of the authors.

Meshfree Continuum Damage Mechanics Modelling for 3D Orthogonal Woven Composites

2011 ◽  
Vol 488-489 ◽  
pp. 759-762
Author(s):  
L.Y. Li ◽  
M.H. Aliabadi ◽  
Pi Hua Wen
Keyword(s):  
Damage Mechanics ◽  
Shape Function ◽  
Cell Model ◽  
Continuum Damage Mechanics ◽  
Unit Cell ◽  
Woven Composites ◽  
Continuum Damage ◽  
Unit Cell Model ◽  
Cell Models ◽  
3D Orthogonal Woven

A Meshfree approach for continuum damage modeling of 3D orthogonal woven composites is presented. Two different shape function constructions, Radial basis (RB) function and Moving kriging (MK) interpolation, are utilized corresponding with Galerkin method in the Meshfree approach. The failure of two different unit cell models, straight-edge and smooth fabric unit cell model respectively, is compared.

A Nonlinear Damage Model of Hardening-Softening Materials

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
M. Ganjiani
Keyword(s):  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Tensile Tests ◽  
Internal Variable ◽  
Integration Algorithm ◽  
Finite Element Program ◽  
Variable Theory ◽  
Numerical Predictions ◽  
Type Variable

In this paper, an elastoplastic-damage constitutive model is presented. The formulation is cast within the framework of continuum damage mechanics (CDM) by means of the internal variable theory of thermodynamics. The damage is assumed as a tensor type variable and its evolution is developed based on the energy equivalence hypothesis. In order to discriminate the plastic and damage deformation, two surfaces named as plastic and damage are introduced. The damage surface has been developed so that it can model the nonlinear variation of damage. The details of the model besides its implicit integration algorithm are presented. The model is implemented as a user-defined subroutine user-defined material (UMAT) in the abaqus/standard finite element program for numerical simulation purposes. In the regard of investigating the capability of model, the shear and tensile tests are experimentally conducted, and corresponding results are compared with those predicted numerically. These comparisons are also accomplished for several experiments available in the literature. Satisfactory agreement between experiments and numerical predictions provided by the model implies the capability of the model to predict the plastic deformation as well as damage evolution in the materials.

Energy Absorption of Braided Glass Fiber Reinforced Composite Tubes

2000 ◽  
Author(s):  
Shu Ching Quek ◽  
Anthony M. Waas
Keyword(s):  
Glass Fiber ◽  
Energy Absorption ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Fiber Composite ◽  
Continuum Damage Mechanics ◽  
Composite Tubes ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Composite

Abstract Results from an experimental and analytical study on the behavior of braided glass fiber composite tubes under quasi-static crush conditions are presented. The composite tubes have an initiator plug introduced at one open end (chamfered) while the other end is clamped. This procedure causes the tube to ‘flare’ outwards into fronds and results in the progressive failure of the tube in the axial and hoop direction without global tube buckling. Axial force and axial displacements are measured during these tests in order to assess energy absorption. In addition, readings from strain gages that are placed at critical locations on the tube walls are used to assess the state of strain on the tube walls away from the crush end. During a crush test, the axial load ascended to a maximum value and subsequently settled to a plateau value about which the load oscillated during the progressive crushing of the tube. The oscillations exhibited distinct periodicity. Results from an analytical model that best simulates the failure of these tubes are presented. The model is based on an axisymmetric formulation of the cylindrical shell equations in conjunction with ideas from classical fracture mechanics and continuum damage mechanics.

Micromechanical Continuum Damage Analysis of Plain Woven Composites

2015 ◽  
Vol 06 (03) ◽  
pp. 1550009 ◽  
Author(s):  
L. Li ◽  
F. Aliabadi ◽  
P. H. Wen
Keyword(s):  
Galerkin Method ◽  
Radial Basis Function ◽  
Basis Function ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Woven Composites ◽  
Moving Least Squares ◽  
Damage Analysis ◽  
Continuum Damage ◽  
Shape Functions

Application of meshfree Galerkin method to homogenization and Continuum Damage Mechanics (CDM) analysis of plain woven composites is presented. Three types of meshfree formulations are developed and include: radial basis function, moving least squares and moving Kriging. Three benchmark examples are used to demonstrated the efficiency of the meshfree formulation as well as compare the performance of the three shape functions. Non-linear stress–strain relationhip of unit cellusing the three shape functions are assessed with two benchmark examples of CDM model.

THE FOUNDATIONS OF CONTINUUM DAMAGE MECHANICS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Siamak Yazdani ◽  
Sevenn Borgersen ◽  
Asli Pelin Gurgun ◽  
Hossein Nazari
Keyword(s):  
Damage Mechanics ◽  
Nonlinear Behavior ◽  
Continuum Damage Mechanics ◽  
Uniaxial Stress ◽  
Internal Variable ◽  
Continuum Damage ◽  
Damage Potential ◽  
Variable Theory ◽  
Wide Range ◽  
The Many

Damage Mechanics has become a useful theory in describing the nonlinear behavior of solids driven by the nucleation and growth of cracks and microcracks. This approach, based on the first principles of mechanics and thermodynamics, has also been combined with classical theories of plasticity to address a wide range of loading applications. In spite of the many different damage mechanics models and representations that are proposed, the foundation of damage mechanics is not well understood or at least not thoroughly published giving rise to the many inaccurate definitions and formulations. The intent of this paper is to provide the background of the continuum damage mechanics outlining the fundamentals on which this field theory is set up. The internal variable theory of continuum thermodynamics is reviewed and is shown that with Legendre transformation technique, various potential functions can be developed for damage mechanics formulation in either stress or strain space. The concept of constrained or neighboring equilibrium state is also introduced and is explained. The paper will conclude with the derivation of the general damage potential and a suggestion is given for the isotropic damage formulation with the resulting uniaxial stress-strain relation.

scholarly journals Nonlocal Theories in Continuum Mechanics

10.14311/610 ◽  
2004 ◽  
Vol 44 (5-6) ◽  
Author(s):  
M. Jirásek
Keyword(s):  
Damage Mechanics ◽  
Continuum Theory ◽  
Nonlinear Behavior ◽  
Continuum Damage Mechanics ◽  
Internal Variable ◽  
Continuum Damage ◽  
Hardening Modulus ◽  
Wide Range ◽  
Discrete Media ◽  
Dynamic Phenomena

The purpose of this paper is to explain why the standard continuum theory fails to properly describe certain mechanical phenomena and how the description can be improved by enrichments that incorporate the influence of gradients or weighted spatial averages of strain or of an internal variable. Three typical mechanical problems that require such enrichments are presented: (i) dispersion of short elastic waves in heterogeneous or discrete media, (ii) size effects in microscale elastoplasticity, in particular with the size dependence of the apparent hardening modulus, and (iii) localization of strain and damage in quasibrittle structures and with the resulting transitional size effect. Problems covered in the examples encompass static and dynamic phenomena, linear and nonlinear behavior, and three constitutive frameworks, namely elasticity, plasticity and continuum damage mechanics. This shows that enrichments of the standard continuum theory can be useful in a wide range of mechanical problems. 

Continuum Damage Mechanics for Thermo-Piezoelectric Materials

2006 ◽  
Vol 22 (2) ◽  
pp. 93-98 ◽  
Author(s):  
X.-H. Yang ◽  
Y. Zhang ◽  
Y.-T. Hu ◽  
C.-Y. Chen
Keyword(s):  
Damage Mechanics ◽  
Effective Properties ◽  
Virtual Work ◽  
Piezoelectric Materials ◽  
Mechanical Damage ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Numerical Illustration ◽  
Damage And Fracture ◽  
Reliable Design

AbstractWith rapidly increasing use of piezoelectric materials in high-temperature environment, it is becoming increasingly important for reliable design of piezoelectric devices to study thermo-electroelastic damage and fracture mechanism. As the first step, a thermo-piezoelectric damage constitutive model is presented from continuum damage mechanics and effective properties of a damaged material are connected with both damages and the initial coefficients according to the theorem of energy equivalence in this paper. Then the finite element equations for a thermo-electroelastic damage problem are given by use of the virtual work principle. Finally, as a numerical illustration example, damage fields around a crack-tip in a three-point bending PZT-5H beam subjected to different thermal loads are calculated and analyzed. It is shown from both the damage curves and contours that influence of environmental temperature on the mechanical damage distribution is great but slight on the electrical damage.

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