Tensile test on smooth and circumferentially notched specimens, systematic observation of fracture surfaces and large deformation finite element analysis were conducted to understand the deformation and failure behavior of a magnesium alloy (AM60). The plastic deformation is considered to be dominated by twining mediated slip. The tensile properties were not sensitive to the strain rates applie...

A unified experimental-computational study on ductile fracture initiation and propagation during small punch testing is presented. Tests are carried out at room temperature with unnotched disks of different thicknesses where large-scale yielding prevails. In thinner specimens, the fracture occurs with severe necking under membrane tension, whereas for thicker ones a through thickness shearing m...

By employing the in situ transmission electron microscopy (TEM) technique, tensile deformation behaviors of a silver nanowire (NW) with a single twin structure were studied. Our observations revealed that the initial stage of plastic deformation was dominated by surface-mediated partial dislocation activities. Strikingly, the void formation and growth were shown to govern the later stage of pla...

We describe the historical development of large-scale nonequilibrium molecular-dynamics (NEMD) computer simulations of fracture at Los Alamos. We have found that dynamic crack propagation leads to energy buildup that seeds instabilities, such as dislocation emission and branching. Recent three-dimensional simulations have shed light on ductile fracture mechanisms, including sequences of disloca...

The fracture toughness and uniaxial tensile yield strengths of unmodified and CTBN-rubbermodified epoxies were measured under hydrostatic pressure. The purpose of these experiments was to learn how suppressing cavitation in rubber particles affects the deformation mechanisms and the fracture toughness of rubber-modified epoxy. It was found that the cavitation of CTBN-rubber could be suppressed ...

In this paper, we report that silver films evaporated on poly-ethylene-terephthalate (PET) substrates coated with an acrylic primer can be stretched beyond 70% without fracture. As-deposited films show a larger failure strain than annealed coatings. These observations are rationalized in light of a ductile fracture mechanism where debonding from the substrate coevolves with strain localization....

Austempered ductile iron (ADI) has been proved to be an excellent material as it possesses attractive properties: high strength, ductility and toughness combined with good wear resistance and machinability. These properties can be achieved upon adequate heat treatment which yields the optimum microstructure for a given chemical composition. The heat treating of the ductile cast iron produces th...

Fracture experiments in a high-strength ductile steel (2.3Ni-1.3Cr-0.17C) were conducted under static and dynamic loading conditions in a three-point bend and a one-point bend configurations. A qualitative description of the influence of loading rate on the microscopic features of the fracture surfaces and their role in the fracture initiation process was considered. The fracture surfaces consi...

Pressure vessels are used in variety of industries like petroleum refining, oil and gas, chemical, power, fertilizers etc. In this paper the rupture phenomenon occurring in the ductile failure has been studied using the Fracture Mechanics approach. The material selected for this study is the low carbon steel (SA-516 Grade 70) widely used for making pressure vessels. Compact Tension (C(T)) speci...