In this work, a meshfree method is used to simulate thermo-mechanical ductile fracture under finite deformation. A Galerkin meshfree formulation incorporating the Johnson-Cook damage model is implemented in numerical computations. We are interested in the simulation of thermomechanical effects on ductile fracture under large scale yielding. A rate form adiabatic split is proposed in the constit...

A molecular-dynamics study of ductile and brittle fracture in model noncrystalline solids Abstract Molecular-dynamics simulations of fracture in model amorphous solids are shown to exhibit brittle or ductile behavior depending on small changes in interatomic potential. Yet, simulations of these two model solids under pure shear reveal no significant difference in their ultimate yield stress. To...

The Earth stands out in the solar system as the only planet with plate tectonics. This peculiarity is due not only to strong internal heating but also a lithosphere rheology characterized by brittle failure and localization, as a comparison with Venus clearly show. Localization in the ductile regime are manifested on Earth by ductile shear zones, which have proven difficult to explain theoretic...

[1] We have conducted double‐shear biaxial deformation experiments in layers of NaCl within its fully‐plastic (FP) regime up to large shear strains (g < 50) with velocity steps. From this, we have empirically formulated a rate‐ and state‐dependent flow law which explains the transient mechanical behavior. The steady state flow stress in the FP regime can be explained by a power‐law with a stres...

Sea ice contains flaws including frictional contacts. We aim to describe quantitatively the mechanics of those contacts, providing local physics for geophysical models. With a focus on the internal friction of ice, we review standard micro-mechanical models of friction. The solid’s deformation under normal load may be ductile or elastic. The shear failure of the contact may be by ductile flow, ...

Ductile-brittle fracture transition was investigated using compact tension (CT) specimens from -70 o C to 40 o C for a carbon steel. Large deformation finite element analysis has been carried out to simulate the stable crack growth in the compact tension (CT, a/W=0.6), three point-point bend (SE(B), a/W=0.1) and centre-cracked tension (M(T), a/W=0.5) specimens. Experimental crack tip opening di...

The enrichment of coalbed methane (CBM) and the outburst of gas in a coal mine are closely related to the nanopore structure of coal. The evolutionary characteristics of 12 coal nanopore structures under different natural deformational mechanisms (brittle and ductile deformation) are studied using a scanning electron microscope (SEM) and low-temperature nitrogen adsorption. The results indicate...

In this work, the plastic deformation mechanisms responsible for mechanical properties and fracture toughness in nanotwinned (NT) magnesium is studied by molecular dynamics (MD) simulation. The influence of twin boundary (TBs) spacing and crack position on deformation behaviors are investigated. The microstructure evolution at the crack tip are not exactly the same for the left edge crack (LEC)...

This paper studies the surface finish and integrity of glass, silicon, some advanced ceramics and aluminum-based metal matrix composites (MMCs) reinforced with ceramic particles, precision machined by various machining processes. The studies revealed that grinding/lapping operations using inexpensive machine tools can produce ductile streaks on glass and silicon surfaces under good grinding/lap...

[1] Geothermobarometric together with microand macro-structural data indicate ductile flow in the metamorphic core of the Himalaya in the Garhwal region of India. Peak metamorphic pressure and temperature increase dramatically across the Main Central Thrust (MCT) from !5 kbar and !550°C in the Lesser Himalayan Crystalline Sequence (LHCS) to !14 kbar and !850°C at !3 km above the MCT in the Grea...