In this paper, two different techniques for mixed-mode type engineering fracture analysis, by using the weight-function method, are presented. These two methods are (a) the virtual crack extension technique (VCE), and (b) the equivalent domain integral method (EDI). For mixed-mode weight-function evaluation, a technique of using two reference load states, both of which cannot be either pure mod...

We have conducted experiments and numerical simulations to investigate supersonic cracks. The experiments are performed at 85 ◦C to suppress strain-induced crystallites that complicate experiments at lower temperature. Calibration experiments were performed to obtain the parameters needed to compare with a theory including viscous dissipation. We find that both experiments and numerical simulat...

Acoustic measurements, using longitudinal waves in plane specimens, based on the theory of acoustoe~asticity, permit the determination of the sum of the principal stresses (crl + cr2). By automatic scannlng, we are able to make such measurements throughout a region of interest. In this paper we shall be concerned with the application of this acoustoelastic stress analysis to fracture mechanics....

A theory is provided for piezoresistivity in carbon fiber reinforced cement (with and without embedded steel reinforcing bars) under flexure (three-point bending). The phenomenon, which involves the reversible increase of the tension surface electrical resistance and the reversible decrease of the compression surface electrical resistance upon flexure, allows strain sensing. The theory is based...

ÐTransient cyclic fatigue-crack growth behavior following variable-amplitude loading sequences has been investigated in a hot-pressed, monolithic Si3N4 ceramic (NTK EC-141), for which fracture toughness (resistance-curve) and cyclic fatigue properties are well characterized. Following rapid changes in the applied stress-intensity range, DK, during both low-high and high-low block-loading sequen...

This paper presents a formulation for brittle fracture in 3D elastic solids within the context of configurational mechanics. The local form of the first law of thermodynamics provides a condition for equilibrium of the crack front. The direction of the crack propagation is shown to be given by the direction of the configurational forces on the crack front that maximise the local dissipation. Th...