Reliability Study of Notched Composite Laminates Under Uniaxial Loading Based on Continuum Damage Mechanics Approach

2021 ◽  
Author(s):  
Mohammad Nadjafi ◽  
Peyman Gholami
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Uniaxial Loading ◽  
Continuum Damage ◽  
Reliability Study

Coupling of Continuum Damage Mechanics with De-Cohesive Element for Delamination Analysis in Laminated Composites

2010 ◽  
Vol 123-125 ◽  
pp. 527-530
Author(s):  
Hossein Hosseini-Toudeshky ◽  
Bijan Mohammadi
Keyword(s):  
Mesh Generation ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Plate Theory ◽  
Continuum Damage Mechanics ◽  
Constitutive Law ◽  
Interface Element ◽  
Continuum Damage ◽  
Interface Modeling ◽  
Edge Delamination

To predict the progressive damages including the large delamination growth in composite laminates, a new interface de-cohesive constitutive law is developed which is compatible with 3D continuum damage mechanics (CDM). To avoid the difficulties of 3D mesh generation and 3D interface modeling between the layers, the interface element is implemented in the Reddy’s full layer-wise plate theory. An angle-ply laminate is analyzed to evaluate the developed CDM+Interface procedure in edge delamination initiation and evolution at final stage of CDM damage progress.

scholarly journals Continuum damage mechanics modeling of composite laminates including transverse cracks

2017 ◽  
Vol 27 (6) ◽  
pp. 877-895 ◽  
Author(s):  
Tomonaga Okabe ◽  
Sota Onodera ◽  
Yuta Kumagai ◽  
Yoshiko Nagumo
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Elastic Moduli ◽  
Crack Density ◽  
Continuum Damage Mechanics ◽  
Damage Variable ◽  
Continuum Damage ◽  
Transverse Cracks ◽  
Element Analysis ◽  
The Finite Element Analysis

In this study, the continuum damage mechanics model for predicting the stiffness reduction of composite laminates including transverse cracks is formulated as a function of crack density. To formulate the model, first the damage variable in the direction normal to the fiber of a ply including transverse cracks is derived. The damage variable is derived by the model assuming a plane strain field in the isotropic plane and using the Gudmundson–Zang model for comparison. The effective compliance based on the strain equivalent principle proposed by Murakami et al. and classical laminate theory are then used to formulate the elastic moduli of laminates of arbitrary lay-up configurations as a function of the damage variable. Finally, the results obtained from this model are compared to the finite-element analysis reported in previous studies. The model proposed in this paper can predict the stiffness of laminates containing damage due to transverse cracks (or surface crack) from just the mechanical properties of a ply and the lay-up configurations. Furthermore, this model can precisely predict the finite-element analysis results and experiment results for the elastic moduli of the laminate of arbitrary lay-up configuration, such as cross-ply, angle ply, and quasi-isotropic, including transverse cracks. This model only considers the damage of the transverse crack; it does not consider damage such as delamination. However, this model seems to be effective in the early stage of damage formation when transverse cracking mainly occurs. The model assuming plane strain field in the isotropic plane which is proposed in this paper can calculate the local stress distribution in a ply including transverse cracks as a function of crack density. The damage evolution of transverse cracks can thus be simulated by determining the fracture criterion.

Modelling Damage of Composite Laminates with Different Stacking Sequences

2013 ◽  
Vol 698 ◽  
pp. 1-10
Author(s):  
S. Benbelaid ◽  
B. Bezzazi ◽  
A. Bezazi
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Failure Criteria ◽  
Continuum Damage ◽  
Damage Development ◽  
Numerical Application ◽  
Element Analysis

This paper considers damage development mechanisms in composite laminates subjected to tensile loading. The continuum damage mechanics is the most widely used approach to capture the non linear behaviour of laminates due to cracking. In this study, a continuum damage model based on ply failure criteria, which is initially proposed by Ladevèze has been extended to cover all plies failures mechanisms using an accurate numerical model to predict the equivalent damage accumulation. However, this model requires a reliable representation of the elementary damage mechanisms which can be produced in the composite laminate. To validate this model, a numerical application has been carried on the cross-ply laminates of type [0n/90m]s..A shear lag model was adapted to calculate the average stress of the 0° and 90° plies. The solution presented is obtained by using finite element analysis which implements progressive failure analysis. The effect of the stacking sequences has been done by varying the thickness of the 90° plies.

scholarly journals Analytical model for determining effective stiffness and mechanical behavior of polymer matrix composite laminates using continuum damage mechanics

2020 ◽  
Vol 29 (10) ◽  
pp. 1512-1542
Author(s):  
Sota Onodera ◽  
Tomonaga Okabe
Keyword(s):  
Analytical Model ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Shear Loading ◽  
Effective Stiffness ◽  
Continuum Damage ◽  
Transverse Tensile ◽  
Stiffness Reduction ◽  
Fiber Breaks

The present paper proposes a new analytical model for predicting the effective stiffness of composite laminates with fiber breaks and transverse cracks. The model is based on continuum damage mechanics and the classical laminate theory. We derived damage variables describing stiffness reduction due to fiber breaks and its maximum value during ultimate tensile failure from the global load-sharing model. Furthermore, a simplified analytical model is presented for obtaining two damage variables for a cracked ply subjected to transverse tensile loading or in-plane shear loading. This model was developed assuming that the displacement field of the longitudinal direction can be expressed in the form of a quadric function by loosening the boundary condition for the governing differential equation. For verifying the developed model, the elastic constants of damaged composite laminates were predicted for cross-ply and angle-ply laminates and compared with the finite element analysis results. As for the appropriate expression of the effective elastic stiffness matrix of the damaged ply, we verified four types of effective compliance/stiffness matrices including the Murakami, Yoshimura, Li, and Maimí models. We found the Maimí model to be the most appropriate among these four models. Moreover, we successfully simplified the expressions for damage variables in the complicated infinite series obtained in our previous study. We also proved that this could contribute toward improving the accuracy of our analysis. After verifying the present model, the stress–strain response and failure strength of carbon- or glass-fiber-reinforced plastic cross-ply laminates were predicted using Maimí’s compliance model and the simplified damage variables.

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