A Self-Consistence Numerical Method to Estimate Effective Mechanical Properties of Fibrous Composites

Vasheghani, Koorosh | 2017

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 49291 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Hosseini Kordkhaili, Ali
  7. Abstract:
  8. One of the most widely used methods in the study of the mechanical behavior of fiber-reinforced polymers is modeling and simulation of a unit cell behavior. According to the arrangement of composite materials, the unit cell is selected in order to include and represent actual constructions of the material. In this study a numerical self-consistence method is proposed to estimate effective properties of Carbon-epoxy composite materials. In this method, in addition of two main phases i.e. matrix and fiber, a phase of composite properties is also considered surrounding the unit cell. First using analytical and semi-empirical methods, the properties are calculated and are converged after iterations. It has been shown that the results have acceptable agreement with the experiments. Development and utility of the multi-scale methods for an accurate analysis of composite materials is necessary. In this method a transformation from macro to micro phase is needed. The transformation is accomplished by a stress amplification factor matrix. The presence of a damage in the material causes the tensor elements to change. Using FEM analysis of the unit cell and applying monotonic stress under periodic boundary conditions, and defining damage parameter by damage bilinear model, the damage is simulated in the matrix. The damage effect on the diagonal elements of the stress amplification factor matrix is studied in a mean view. In this study, a method for calculation of the average value of the stress amplification factor matrix is proposed versus damage in order to be used in multi-scale analysis
  9. Keywords:
  10. Micromechanics ; Property ; Multiscale Modeling ; Amplification Factor ; Numerical Solution ; Progressive Damage, Bilinear Model

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