Under uniaxial tension, high-density polyethylene (HDPE) often fractures in a ductile manner. The fracture involves extensive necking that is known to occur in the plane-stress condition. However, for large-scale HDPE products like polyethylene pipe, crack can grow rapidly in a brittle manner. This type of fracture is known to be in the plane-strain condition, which has much lower toughness tha...

Charpy V-notch impact testing is widely used in the toughness assessment of large forged components, e.g. the pressure vessel for pressurised water reactors m). At low temperature, A508 C1.3 nuclear pressure vessel steel fails by cleavage fracture. The results reported here are part of both an experimental program and numerical investigations which aim at the establishment of a non-empirical re...

Bone fragility is a concern for aged and diseased bone. Measuring bone toughness and understanding fracture properties of the bone are critical for predicting fracture risk associated with age and disease and for preclinical testing of therapies. A reference point indentation technique (BioDent) has recently been developed to determine bone's resistance to fracture in a minimally invasive way b...

Recent studies document linear elastic response of muddy marine sediments to load and deformation on temporal and spatial scales relevant to animal movement, with burrowers making openings for movement in such sediments by fracture. Cracks propagate through linear elastic solids in mode I (opening-mode crack growth) when the stress intensity factor (KI) at the crack tip exceeds the material’s f...

Abstract: Zirconia solid electrolytes with nonequilibrium composite structure were prepared by impregnation of a porous 8YSZ matrix with a solution of Zirconia. Microstructures were characterized by XRD and SEM. The electrical properties were studied by impedance spectroscopy as a function of temperature. Biaxial flexural strength and fracture toughness of composite samples were measured by rin...

Abrasive machining in general and grinding in particular are processes, which increase their importance with high demands on accuracy of surface finish. The chip thickness is an evaluating variable to describe the quality of ground surface as well as the performance of the overall grinding system. A significant characteristic that distinguishes ceramics from metals is their low fracture toughne...

The fracture toughness of the refractory hardmetal TisSi3, with a grain size between 5 and 6 lam, was measured using the controlled-flaw method in conjunction with the miniaturized disc-bend test. The specimens used in these experiments were 3 mm diameter and varied in thickness from 150-450 lam. They were indented using a Vickers pyramid indentor to indention loads varying from 2.9-79.2 N. Ind...

The increasing need in the mechanical testing of sub-sized samples motivated the present study focused on the effect of the size of samples. Sometimes, attempts are made, due to economic reasons, to replace testing of the fracture toughness by a cheaper testing of notch toughness. Several empirical relations, pertaining to relations between fracture toughness and energy consumption in impact te...

an epoxy resin was modified by silica nanoparticles and cured with an anhydride. the particles with different batches of 12, 20, and 40 nm sizes were each distributed into the epoxy resin ultrasonically. electron microscopy images showed that the silica particles were well dispersed throughout the resin. tensile test results showed that young’s modulus and tensile strength increased with the vo...

The fracture toughness of snow in shear is one of the most relevant parameters when studying the mechanics of snow slab avalanche release. Double-cantilever snow beams were loaded asymmetrically to determine K(IIc). If crack surfaces touch under applied pressure, the fracture toughness in shear of snow (rho=247 kg m(-3)) is K(IIc)=680+/-60 Pa m(1/2). Screening of the stress intensity at the cra...