Intra and damage analysis of laminated composites using coupled continuum damage mechanics with cohesive interface layer

2015 ◽  
Vol 120 ◽  
pp. 519-530 ◽  
Author(s):  
Bijan Mohammadi ◽  
Hamed Olia ◽  
Hossein Hosseini-Toudeshky
Keyword(s):  
Damage Mechanics ◽  
Laminated Composites ◽  
Continuum Damage Mechanics ◽  
Interface Layer ◽  
Damage Analysis ◽  
Continuum Damage ◽  
Cohesive Interface

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.

scholarly journals Textile Composite Damage Analysis Taking into Account the Forming Process

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5337
Author(s):  
Marjorie Jauffret ◽  
Aldo Cocchi ◽  
Naim Naouar ◽  
Christian Hochard ◽  
Philippe Boisse
Keyword(s):  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Woven Fabric ◽  
Damage Analysis ◽  
Continuum Damage ◽  
Woven Composite ◽  
Textile Composite ◽  
Forming Process ◽  
Composite Damage ◽  
Bias Extension

The internal structure of composite materials is modified during manufacturing. The formation of woven prepregs or dry preforms changes the angle between the warp and weft yarns. The damage behaviour of the consolidated composite is modified by these changes of angle. It is important when designing a composite part to consider this modification when calculating the damage in order to achieve a correct dimensioning. In this paper, a damage calculation approach of the consolidated textile composite that takes into account the change in orientation of the yarns due to forming is proposed. The angles after forming are determined by a simulation of the draping based on a hypoelastic behaviour of the woven fabric reinforcement. Two orthogonal frames based on the warp and weft directions of the textile reinforcement are used for the objective integration of stresses. Damage analysis of the cured woven composite with non-perpendicular warp and weft directions is achieved by replacing it with two equivalent Unidirectional (UD) plies representing the yarn directions. For each ply, a model based on Continuum Damage Mechanics (CDM) describes the progressive damage. Two examples are presented, a bias extension specimen and the hemispherical forming coupon. In both cases, the angles between the warp and weft yarns are changed. It is shown that the damage calculated by taking into account these angle changes is greatly modified.

Fatigue Life of the Human Teeth: A Continuum Damage Approach

2019 ◽  
Vol 43 ◽  
pp. 1-19
Author(s):  
Theddeus Tochukwu Akano
Keyword(s):  
Fatigue Life ◽  
Damage Mechanics ◽  
Stress Amplitude ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Elastoplastic Model ◽  
Human Teeth ◽  
Proposed Model ◽  
Number Of Cycles ◽  
Cycles To Failure

Normal oral food ingestion processes such as mastication would not have been possible without the teeth. The human teeth are subjected to many cyclic loadings per day. This, in turn, exerts forces on the teeth just like an engineering material undergoing the same cyclic loading. Over a period, there will be the creation of microcracks on the teeth that might not be visible ab initio. The constant formation of these microcracks weakens the teeth structure and foundation that result in its fracture. Therefore, the need to predict the fatigue life for human teeth is essential. In this paper, a continuum damage mechanics (CDM) based model is employed to evaluate the fatigue life of the human teeth. The material characteristic of the teeth is captured within the framework of the elastoplastic model. By applying the damage evolution equivalence, a mathematical formula is developed that describes the fatigue life in terms of the stress amplitude. Existing experimental data served as a guide as to the completeness of the proposed model. Results as a function of age and tubule orientation are presented. The outcomes produced by the current study have substantial agreement with the experimental results when plotted on the same axes. There is a notable difference in the number of cycles to failure as the tubule orientation increases. It is also revealed that the developed model could forecast for any tubule orientation and be adopted for both young and old teeth.

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