Study o n two-phase materials

1. Study on two-phase materials Kovács Kornélés Kun Ferenc Debreceni Egyetem Elméleti Fizikai Tanszék

2. Motivation • Materials of high mechanical performance are often fabricated by embedding strong fibers in a relatively weak matrix. The damage process of such two-phase materials can be followed experimentally by recording the acoustic signals - also known as crackling noise - emitted by cracks. This can be used to predict the imminent failure. • By understanding the effect of the two component with widely different mechanical strength, our results shall be used for developing better NDT (non-destructive testing) techniques for such materials.

3. Modell • Extension of the classical FBM: • fraction of fibers are un-breakable • Used set-up in simulations: • L = 101 -> 1001 system size • N = LxL number of fibers • : fraction of strong fibersaz • Load redistribution: • global (GLS) • local (LLS)

4. GLS Constitutive behaviour: • Strength disorder of weak fibers: • Weibull: • Uniform:

5. GLS – Macroscopic response

6. GLS – Avalanches 1 M. Kloster, A. Hansen and P.C. Hemmer, ”Burst Avalanches in Solvable Models of Fibrious Materials”, Phy. Rev. E 56, 2615 (1997)

7. GLS – Avalanches • Power law divergence • Scaling

8. LLS

9. LLS – Macroscopic response The threshold distribution is uniform: • a görbének –ben szakadása van • a görbe folytonossá válik

10. LLS – Avalanches

11. LLS – Avalanches • Power law divergence

12. LLS – Avalanches • Scaling

13. LLS – Avalanches • Skálázhatóság

14. Cluster Size