Kayran, Altan
In this study, a method of strain and stress analysis is developed to determine the stress and strain fields in fibers and matrix of a laminated composite for the cases of nonlinear strain and stress distributions with high gradients. The strain values calculated by using a classical method are considered as input, and the strain fields at each layer are determined. These strain fields are then used as input to express the strains in fibers and matrix. In these processes the heterogeneity effects, which are caused by the existence of different materials in a composite, are taken into account. By the summation of input strains and the heterogeneity strains, the strains in the fibers and the matrix are calculated. By using the fiber and matrix strains in constitutive equations the stresses in fibers and matrix are obtained. The non-classical method is applied to a sample problem and numerical results are presented as well as a comparison of the layer stresses with the results from MSC/Nastran finite element software composite material solution.


Coupled thermoviscoplasticity of glassy polymers in the logarithmic strain space based on the free volume theory
Miehe, Christian; Mendez Diez, Joel; Göktepe, Serdar; Schaenzel, Lisa Marie (Elsevier BV, 2011-06-15)
The paper outlines a constitutive model for finite thermo-visco-plastic behavior of amorphous glassy polymers and considers details of its numerical implementation. In contrast to existing kinematical approaches to finite plasticity of glassy polymers, the formulation applies a plastic metric theory based on an additive split of Lagrangian Hencky-type strains into elastic and plastic parts. The analogy between the proposed formulation in the logarithmic strain space and the geometrically linear theory of pl...
Solution of the dynamic frictional contact problem between a functionally graded coating and a moving cylindrical punch
BALCI, MEHMET NURULLAH; Dağ, Serkan (Elsevier BV, 2019-04-01)
This paper presents an analytical method developed to investigate the dynamic frictional contact mechanics between a functionally graded coating and a rigid moving cylindrical punch. Governing partial differential equations of elastodynamics are solved analytically by applying Galilean and Fourier transformations. Interface continuity and boundary conditions are written and contact problem is then reduced to a singular integral equation of the second kind. The singular integral equation is solved numericall...
An adaptive fully discontinuous Galerkin level set method for incompressible multiphase flows
KARAKUS, Ali; WARBURTON, Tim; AKSEL, MEHMET HALUK; Sert, Cüneyt (Emerald, 2018-01-01)
Purpose This study aims to focus on the development of a high-order discontinuous Galerkin method for the solution of unsteady, incompressible, multiphase flows with level set interface formulation.
A study of phase stability and mechanical properties of hydroxylapatite-nanosize alpha-alumina composites
Evis, Zafer (Elsevier BV, 2007-04-01)
Hydroxylapatite (HA)-nanosize alumina composites were synthesized to study their phase stability and mechanical properties. To make these composites, nanosize alpha-Al2O3 powder was used because of its better sinterability and densification as compared to nanosize gamma-Al2O3. The composites were air sintered without pressure and hot pressed in vacuum at 1100 degrees C and 1200 degrees C. In the composites, HA decomposed to tricalcium phosphate faster after the air sintering than hot pressing. Moreover, hex...
Finite viscoplasticity of amorphous glassy polymers in the logarithmic strain space
Miehe, Christian; Göktepe, Serdar; Mendez Diez, Joel (Elsevier BV, 2009-01-01)
The paper outlines a new constitutive model and experimental results of rate-dependent finite elastic-plastic behavior of amorphous glassy polymers. In contrast to existing kine-matical approaches to finite viscoplasticity of glassy polymers, the formulation proposed is constructed in the logarithmic strain space and related to a six-dimensional plastic metric. Therefore, it a priori avoids difficulties concerning with the uniqueness of a plastic rotation. The constitutive framework consists of three major ...
Citation Formats
E. ARDIC, C. BOLCAN, and A. Kayran, “A METHOD OF STRAIN AND STRESS-ANALYSIS OF COMPOSITES FOR NONLINEAR STRAIN DISTRIBUTION CASE,” INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, pp. 3457–3473, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37676.