The Effect of Volume Fractions on Hole Stress Concentration in Composite Lamina Subjected to Matrix Plasticity

Document Type : Persian

Author

Assistant Professor, Department of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

Abstract

In this paper, the stress concentration around a hole in the single layer composite materials with long fibers is examined. The single layer has an infinite length, limited with and instant thickness and is loaded by a constant tension force p at infinity. The width of the lamina is considered to be finite and bears a hole as a defect. Due to presence of excessive shear stress in the matrix bays bounding the hole, a yielded zone of size  is developed around the hole. Shear lag model (SLM) is used to drive the displacement and stress fields. The resulting equations are solved analytically based on boundary conditions and continuity in governing equations. Finally, the stress concentrations around the hole are calculated using a computer code.  It is shown that the volume fractions of the fiber and matrix, as well as length of the plastic zone, have considerable effect on the stress concentrations within the lamina. Moreover, the number of broken fibers, the total number of fibers and the hole deformation seem to have considerable effect on hole stress concentrations. It is shown the stress concentration coefficient decreases with the increase of the plastic zone length. Also, the stress concentration factor increases in the elastic case with the increase of the volume fraction but in the plastic case at first it increases and then decreases with the increase of the volumes fraction.

Keywords

References

[1] Hedgepth J., Van Dyke P., Local Stress Concentration in Imperfect Filamentary Composite Materials, Journal of Composite Materials, vol. 1, 1967, pp. 294 - 309.
[2] Hedgepth J., Van Dyke P., Stress Concentration from Single Filament Failure in Composite Materials, Textile Research Journal, vol. 39, 1969, pp. 618 – 626.
[3] Franclin H.G., Hole Stress Concentration in Filamentary Structures, Fibers Science and Technology, vol. 2, 1970.
[4] Ko W.L., Nagy A., Francis P.H., Lindholm U. S., Crack Extension in Filamentary Materials, Engineering Fracture Mechanics, vol. 8, 1976, pp. 411– 424.
[5] Rossetos J.N., Shishesaz M., Stress Concentration in Fiber Composite Sheets Including Matrix Extension, Journal of Applied Mechanics, vol. 54, 1987, pp. 723-724.
[6] Landis C.M, McMeeking R.M., A Shear-Lag Model for a Broken Fiber Embedded in a Composite with a Ductile Matrix, Composite Science and Technology, vol. 59, 1999, pp. 447-457.
[7] Sayman O., Aksoy S., Elastic-Plastic Stress Analysis of Simply Supported and Clamped Aluminum Metal-Matrix Laminated Plates with a Hole, Composite Structures, vol. 53, 2001, pp.355-364.
[8] Miserez A., Rossoll A., Mortensen A., Investigation of Crack-tip Plasticity in High Volume Fration Particulate Metal Matrix Composite, Engineering Fracture Mechanics, vol. 71, 2004, pp. 2385-2406.
[9] Peters, S.T., Handbook of Composite, London: Chapman & Hall, 1998.
[10] ASM International Handbook Committee, Engineered Materials Handbook, Composite, Vol. 4, U. S., 1987.
[11] Lubin, G., Handbook of Composite Materials, Van Nostrand Reinhold Company, 1982.
 
 
Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
Volume 8, Issue 2 - Serial Number 2
Summer 2015
Pages 137-148

Files

Share

How to cite

Statistics