scholarly journals Compressive failure of fiber composites containing stress concentrations: Homogenization with fiber-matrix interfacial decohesion based on a total Lagrangian formulation

2019 ◽  
Vol 182 ◽  
pp. 107758 ◽  
Author(s):  
Vedad Tojaga ◽  
Selcuk Hazar ◽  
Sören Östlund
Keyword(s):  
Fiber Composites ◽  
Lagrangian Formulation ◽  
Compressive Failure ◽  
Stress Concentrations ◽  
Fiber Matrix ◽  
Total Lagrangian Formulation

scholarly journals Micro-scale numerical study of fiber/matrix debonding in steel fiber composites

2020 ◽  
Vol 15 ◽  
pp. 155892502091072 ◽  
Author(s):  
Baris Sabuncuoglu ◽  
Stepan V Lomov
Keyword(s):  
Steel Fiber ◽  
Volume Fraction ◽  
Numerical Study ◽  
Glass Fibers ◽  
Fiber Composites ◽  
Steel Fibers ◽  
Opening Angle ◽  
Stress Concentrations ◽  
Fiber Volume ◽  
Fiber Matrix

Fiber/matrix debonding behavior of steel fiber composites is analyzed using a parametric finite element modeling procedure and compared with conventional composites with carbon and glass fibers. Cohesive surfaces are applied to fiber–matrix interface to simulate the debonding behavior, while the interface strength properties of steel fiber are obtained with and without surface treatment. The effect of various parameters on the debonding behavior is investigated, including stress concentrations, fiber diameter, fiber shape, and fiber volume fraction, using the parametric model. The influence of stress concentrations is determined to be much lower than the debonding strength. Debonding damage is more evident in larger fibers compared to smaller ones. Earlier and sudden interface separation is observed with the polygonal steel fibers compared to the circular ones. Increase in the fiber volume ratio increases the debonding opening distance but does not affect the opening angle significantly. The results can be useful for assessing possibilities to use steel fibers to increase toughness of the composites in comparison with glass and carbon reinforcement.

Fiber/matrix interface stress analysis of flax-fiber composites under transverse loading considering material nonlinearity

2020 ◽  
Vol 39 (9-10) ◽  
pp. 345-360
Author(s):  
Baris Sabuncuoglu ◽  
Onur Cakmakci ◽  
Fevzi S Kadioglu
Keyword(s):  
Fiber Composites ◽  
Flax Fiber ◽  
Material Nonlinearity ◽  
Transverse Strain ◽  
Matrix Interface ◽  
Transverse Loading ◽  
Stress Concentrations ◽  
Transverse Cracks ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Distribution of stresses in fiber/matrix interface in UD flax fiber reinforced composites is investigated under transverse loading and compared with conventional synthetic fibers. Micro-scale finite element models with representative volume elements are generated with various fiber packing types and fiber volume ratios. The study is performed for various strain values, which take into account the material nonlinearity of matrix. The results show that significantly lower stress concentrations exist in the case of flax fibers compared to glass fiber composites, explaining the absence of transverse cracks until failure in previously conducted transverse tension tests. Increase in the applied transverse strain causes a further decrease in the stress concentrations due to the nonlinear behavior of the matrix.

Confinement Shear Effect in Fiber Composites

2019 ◽  
Vol 805 ◽  
pp. 170-176
Author(s):  
Pu Zi Zhang ◽  
Jin Xing Liu
Keyword(s):  
Progressive Failure ◽  
Failure Process ◽  
Fiber Composites ◽  
Failure Behavior ◽  
Shear Effect ◽  
Compressive Failure ◽  
Fiber Reinforced Materials ◽  
Matrix Properties ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Composites have been playing an increasingly important role in various engineering applications. We examine the confinement shear effect arising in the neighborhood of the fiber-matrix interface in fiber-reinforced materials, which is a problem calling for further investigations. It is well known that the progressive failure process strongly depends on the interfacial transition zone (ITZ). Thus, we take the studied material as three-phased, i.e. fiber, matrix and interface in between. The generalized beam (GB) lattice model is adopted to simulate the compressive failure behavior of a representative volume element with one fiber included. Numerical results are provided to explain the confinement shear effect during the progressive failure process in specimens with various fiber-matrix properties, fiber orientations and distributions.

Micro-scale finite element analysis of stress concentrations in steel fiber composites under transverse loading

2014 ◽  
Vol 49 (9) ◽  
pp. 1057-1069 ◽  
Author(s):  
Baris Sabuncuoglu ◽  
Svetlana Orlova ◽  
Larissa Gorbatikh ◽  
Stepan V Lomov ◽  
Ignaas Verpoest
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steel Fiber ◽  
Fiber Composites ◽  
Transverse Loading ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Micro Scale

A Mechanistic Approach to Matrix Cracking Coupled with Fiber–Matrix Debonding in Short-Fiber Composites

2005 ◽  
Vol 127 (3) ◽  
pp. 337-350 ◽  
Author(s):  
Ba Nghiep Nguyen ◽  
Brian J. Tucker ◽  
Mohammad A. Khaleel
Keyword(s):  
Damage Mechanics ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Short Fiber ◽  
Matrix Cracking ◽  
Element Analysis ◽  
Pull Out ◽  
Stiffness Reduction ◽  
Mechanistic Approach ◽  
Fiber Matrix

A micro–macro mechanistic approach to damage in short-fiber composites is developed in this paper. At the microscale, a reference aligned fiber composite is considered for the analysis of the damage mechanisms such as matrix cracking and fiber–matrix debonding using the modified Mori–Tanaka model. The associated damage variables are defined, and the stiffness reduction law dependent on these variables is established. The stiffness of a random fiber composite containing random matrix microcracks and imperfect interfaces is then obtained from that of the reference composite, which is averaged over all possible orientations and weighted by an orientation distribution function. The macroscopic response is determined using a continuum damage mechanics approach and finite element analysis. Final failure resulting from saturation of matrix microcracks, fiber pull-out and breakage is modeled by a vanishing element technique. The model is validated using the experimental results found in literature as well as the results obtained for a random chopped fiber glass–vinyl ester system. Acoustic emission techniques were used to quantify the amount and type of damage during quasi-static testing.

Longitudinal Compressive Failure Modes in Fiber Composites: End Attachment Effects on IITRI Type Test Specimens

1985 ◽  
Vol 7 (4) ◽  
pp. 129 ◽  
Author(s):  
KL Reifsnider ◽  
GP Sendeckyj ◽  
SS Wang ◽  
TT Chaio ◽  
W Feng ◽  
...  
Keyword(s):  
Failure Modes ◽  
Fiber Composites ◽  
Compressive Failure ◽  
Type Test
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