Large deformation near a crack tip in a fiber-reinforced neo-Hookean sheet with discrete and continuous distributions of fiber orientations

Author(s):  
Luca Di Stasio ◽  
Yin Liu ◽  
Brian Moran
1975 ◽  
Vol 9 (3) ◽  
pp. 266-287 ◽  
Author(s):  
John F. Mandell ◽  
Su-Su Wang ◽  
Frederick J. Mcgarry

MRS Advances ◽  
2016 ◽  
Vol 1 (12) ◽  
pp. 791-797
Author(s):  
Kabiru Mustapha ◽  
Martiale G. Zebaze Kana ◽  
Winston O. Soboyejo

ABSTRACTThis study presents a combine experimental and analytical investigation of the toughening behavior in natural fiber-reinforced earth-based composites. A specially designed single fiber pullout apparatus was used to provide a quantitative determination of interfacial properties that are relevant to toughening brittle materials through fiber reinforcement. The parameters investigated included a specially designed high strength earth-based matrix comprising of 60% laterite, 20% clay and 20% cement. The toughening behavior of whisker-reinforced earth-based matrix is analyzed in terms of a whisker bridging zone immediately behind the crack tip and interface strength. This approach is consistent with microscopy observations which reveal that intact bridging whiskers exist behind the crack tip as a result of debonding of the whisker-matrix interface. Debonding with constant frictional stress was obtained and this formed the basis for the analytical model considered and the underlying crack-microstructure interactions associated with Resistance-curve behavior was studied using in situ/ex situ optical microscopy to account for the bridging contribution to fracture toughness. The effect of multiple toughening mechanisms (debonding and crack bridging) was elucidated and the implications of the results are considered for potential applications in the design of robust earth-based building materials for sustainable eco-friendly homes.


2010 ◽  
Vol 123-125 ◽  
pp. 603-606
Author(s):  
Mohammad Tahaye Abadi

A viscoelastic model is developed to describe the mechanical response of fiber-reinforced elastomeric composites at large deformation. A continuum approach is used to model the macroscopic mechanical behavior of elastomeric materials reinforced with unidirectional fibers, in which the resin and fibers are regarded as a single homogenized anisotropic material. The anisotropic viscoelastic constitutive model is developed considering transient reversible network theory. An efficient computational algorithm based on micromechanical modeling is proposed to relate the material parameters of constitutive model to the mechanical properties of composite constituents at finite strain. The microstructure is identified by a representative volume element (RVE) and it is subjected to large deformation with considering the conformity of opposite boundaries. The material parameters of the viscoelastic constitutive law are determined based on the response of heterogeneous microstructure which is examined under different loading conditions.


Author(s):  
Zheng-Dong Ma ◽  
Dongying Jiang ◽  
Yuanyuan Liu

A three-dimensional nonlinear thread formulation developed by the first two authors [1] has been extended in this paper for modeling and simulation of woven fabrics and fiber-reinforced composites of various configurations under arbitrary large deformation. The resultant model accounts for extensibility of the woven fibers in the composite, geometry nonlinearity, tension variation along the fiber, and other nonlinear effects due to the woven composition and large deformation. The new modeling effort includes the development of a contact model for simulating the contact between fibers, which can be used to predict high-fidelity behavior of woven fibers in the composite and their interactions. Matrix model is also added into the composite for studying the coupling between woven fibers and matrix material such as resin. The incremental form of original nonlinear equation is discretized using a finite element method with an iteration scheme. Two numerical examples are given to demonstrate the effectiveness of the proposed modeling technique.


2017 ◽  
Vol 12 (1) ◽  
pp. 122
Author(s):  
Emmanuel ET Olodo ◽  
Clement Ahouannou ◽  
Olivier A. Passoli

One of the major concerns in designing of prestressed beams in ultra-high performance fiber- reinforced concrete (UHPFRC) is improvement of their ductility fracture due to the nature of the materials used in their manufacture. This can induce plastic behaviours which it is necessary to take into account by designing of such structures, especially when they are of large spans. In the present work, it is proposed an analytical model in large deformation of a rigid plastic prestressed UHPFRC beam embedded at one end and having at other end rolled support. She is approached by a local uniform load and external moments to supports. The proposed non-linear model can find exact analytical solutions for the determination of the local arrows and the associated charge by the technique of Lagrange multiplier which allows finding the stationary points of differentiable function of one or several variables under constraints. The results of this work can be useful in designing and calculation of long span prestressed structures with plastic rigid behavior.


Author(s):  
Ashish Thakur ◽  
Okqubamariam Leake ◽  
Micheal G. Mariam

The main purpose of this research was to investigate crack propagation resistance of shaft. Hollow transmission composite shafts were produced and their crack behavior was investigated. Glass fiber-reinforced polyester polymer composite material is used for the hollow transmission shaft of Hidasie H260 helicopter model of Dejen Aviation Engineering Complex, DAEC. The elastic engineering constants of composite transmission shaft are determined using the Classic Laminate Theory, CLT. Linear Elastic Fracture Mechanics, LEFM was used to analyze its crack propagation by taking a through-thickness central crack. The stress at the crack tip is analyzed and it was found that the glass fiber-reinforced polyester polymer composite transmission shaft has good resistance to crack propagation. FEA method was used to crack propagation analyses. The model of shaft is generated using Finite Element Method. Due to the symmetry of the problem, only a quarter part of it is modeled and analyzed. The crack-tip region was meshed using quarter point (singular) 8-node quadrilateral elements to get accurate results and the analysis used a fit of the nodal displacements in the vicinity of the crack tip. The maximum stress is at the crack tip since there is a stress concentration at sharp edges.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2024
Author(s):  
Jun Liang ◽  
Chunjing Wu ◽  
Zihang Zhao ◽  
Weizhong Tang

In order to promote the industrialization of the large deformation technology of carbon fiber composites, this paper studies a new method of forming of helical carbon fiber reinforced aluminum matrix composite. The purpose is to solve the problem of large deformation of carbon fiber with low elongation and metal matrix with high elongation. By introducing carbon fiber with helical space structure into the aluminum matrix, the helical carbon fiber reinforced aluminum matrix composites were prepared and the subsequent drawing deformation was carried out. Here we systematically studied the large plastic deformation behavior of helical carbon fiber reinforced aluminum matrix composite via a combination of numerical simulations and experiments, and analyzed the deformation law and stress of helical carbon fiber in the deformation process. We found that the plastic deformation of the composite causes local stress concentration around the helical carbon fiber, and the helical carbon fiber will move synchronously with the aluminum matrix during the deformation, and receive the pressure from the aluminum matrix. Second, the best process parameters obtained from the simulation, that is, the drawing die angle α = 7°, when five-pass drawing experiments were carried out, the total deformation reached 58%, and the average elongation of a single pass was 18.9%. The experimental show carbon fiber reinforced aluminum matrix composite with helical space structure can achieve large deformation and high strength. The experimental and simulation are in general agreement, which verifies the correctness of the carbon fiber helical structure model.


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