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ءاتونى زبر الحديدحتى إذا ساوى بين الصدفين قال انفخوا حتى إذا جعله نارا قال ءاتونى أفرغ عليه قطرا فما اسطاعوا أن يظه

”. ءاتونى زبر الحديدحتى إذا ساوى بين الصدفين قال انفخوا حتى إذا جعله نارا قال ءاتونى أفرغ عليه قطرا فما اسطاعوا أن يظهروه وما استطاعوا له نقبا صدق الله العظيم. *. “. سورة الكهف ، الاية 96و97. Fatigue and Fracture Behavior of Composites. by Hossam Sallam, Ph.D.

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ءاتونى زبر الحديدحتى إذا ساوى بين الصدفين قال انفخوا حتى إذا جعله نارا قال ءاتونى أفرغ عليه قطرا فما اسطاعوا أن يظه

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  1. ” ءاتونى زبر الحديدحتى إذا ساوى بين الصدفين قال انفخوا حتى إذا جعله نارا قال ءاتونى أفرغ عليه قطرا فما اسطاعوا أن يظهروه وما استطاعوا له نقبا صدق الله العظيم * “ سورة الكهف ، الاية 96و97

  2. Fatigue and Fracture Behavior of Composites by Hossam Sallam, Ph.D. Materials Engineering Department, Zagazig University

  3. Objective The goal of this review article is to present a sound background regarding the development of the understanding of the fracture processes and fatigue damage in composite materials and show how they act as a foundation for current models. This presentation shows the importance of matrix, reinforcement, and reinforcement/matrix interface in fatigue and fracture behavior of composite materials. Composites exhibit an unusual combination of brittle and ductile phenomena.

  4. out line • Introduction • Continuous Fiber-Reinforced Composites • Short Fiber-Reinforced Composites • Particulate-Reinforced Composites • Summary

  5. COMPOSITE MATERIALS

  6. Introduction to Fracture Mechanics • Linear Elastic Fracture Mechanics (LEFM) * SIF, K * plain strain fracture Toughness, KIc • Elastic-Plastic Fracture Mechanics (EPFM) * J-integral * Crack Tip Opening Displacement (CTOD) * Crack tip Deformation

  7. S N Introduction to Fatigue of Materials • Wohler’s S-N Curve, 1871 • da/dN-DK curve Elber,1970 Paris Law, 1963 da/dN da/dN DKeff DK DKth Kc

  8. out line • Introduction • Continuous Fiber-Reinforced Composites • Short Fiber-Reinforced Composites • Particulate-Reinforced Composites • Summary

  9. Continuous Fiber-Reinforced Composites • Fiber Bridging • Shear lag Models • Fiber Pressure model Crack Front Debonding Fiber Bridging Fiber Pull-out Matrix Crack Wake Debonding/Sliding The various mechanisms that accompany mode I matrix crack propagation in unidirectional composites

  10. out line • Introduction • Continuous Fiber-Reinforced Composites • Short Fiber-Reinforced Composites • Particulate-Reinforced Composites • Summary

  11. Short Fiber-Reinforced Composites Fiber Reinforced Concrete Microcrack P Microfiber PC Stress Crack P Large Fiber Strain Illustration of different sizes fibers on crack bridging

  12. out line • Introduction • Continuous Fiber-Reinforced Composites • ShortFiber-Reinforced Composites • Particulate-ReinforcedComposites • Summary

  13. Particulate-Reinforced Composites • Ductile Particle in Brittle Matrix (c) (a) (b) The stages of crack propagation

  14. Brittle Particle in Ductile Matrix (a) High strength matrix & Coarse particles (b) Strong interface & High modulus of particles (c) Weak interface Possible particle-crack tip interactions in fatigue crack growth

  15. out line • Introduction • Continuous Fiber-Reinforced Composites • ShortFiber-Reinforced Composites • Particulate-Reinforced Composites • Summary

  16. Summary • Crack-Tip Shielding Mechanisms (b) Zone Shielding (a) Crack Deflection - microcrack toughening (c) Contact Shielding • Wedging • Bridging - corrosion-induced crack closure - roughness-induced crack closure (d) Combined Zone and Contact Shielding - plasticity-induced crack closure

  17. الحمد لله رب العالمين وشكراَ

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