Abstract In their temperature window of application, TiAl alloys typically fail in a semi-brittle manner. For this material class, the Griffith concept, developed initially for ideal brittle materials, has to be adapted by additional dissipative contributions fracture resistance: plastic deformation, crack bridging, work deform and shear ledges, bifurcation. These terms resistance induce pronou...

We report a study of dynamic cracking in a silicon single crystal in which the ReaxFF reactive force field is used for ~3,000 atoms near the crack tip while the other 100,000 atoms of the model system are described with a simple nonreactive force field. The ReaxFF is completely derived from quantum mechanical calculations of simple silicon systems without any empirical parameters. Our results r...

Continuing in the vein of a recently developed generalization of continuum thermomechanics, in this paper we extend fracture mechanics and beam mechanics to materials described by fractional integrals involving D, d and R. By introducing a product measure instead of a Riesz measure, so as to ensure that the mechanical approach to continuum mechanics is consistent with the energetic approach, sp...

The mechanical characterization of mortars is problematic due to their sensitivity to stress concentration defects, namely pores and flaws. In this paper, data on three-point bending, Young’s modulus and fracture toughness of mortar beams are presented and discussed. Here, Weibull statistics is applied to analyse flexural strength of the developed mortar. Based on data obtained according to the...

This paper describes experimental observations of various phenomena characteristic of dynamic intersonic decohesion of bimaterial interfaces[ Two separate but complementary optical methods are used in con! junction with high!speed photography to explore the nature of the large!scale contact and mach wave formation at the vicinity of running cracks in two di}erent bimaterial systems[ Theoretical...

Material failure is accompanied by important heat exchange, with extremely high temperature - thousands of degrees - reached at crack tips. Such a temperature may subsequently alter the mechanical properties of stressed solids, and finally facilitate their rupture. Thermal runaway weakening processes could indeed explain stick-slip motions and even be responsible for deep earthquakes. Therefore...

In this paper, we’ll answer several abstract, formal questions about the nature of crack growth and nucleation. Bringing a field theory point of view to fracture illuminates things in what I hope will be an entertaining way. Formally, what is the crack nucleation rate? Fracture is an instability of elastic theory under tension. For thermally nucleated cracks, there is an analogy with supercoole...