Dynamic crack propagation in a unidirectional carbon/epoxy composite is studied through finite element analyses of asymmetric impact (shear loading) of a rod against a rectangular plate. A finite deformation anisotropic visco-plastic model is used to describe the constitutive response of the composite. Crack propagation is simulated by embedding zero thickness interface element along the crack ...

hydraulic fracturing (hf), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. the combination of horizontal drilling and multiple hf with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. despite the wide use of hf, there are still ambiguous aspects that requi...

In this study, 5052 Al–Mg alloy was pre-treated and friction stir processing (FSP) was then performed on the specimens to explore the deformation resistance. The experimental results indicate that the FSP specimens not only had better tensile properties but also better vibration fracture resistance. It is significant that the tensile elongation and deformation resistance tended to increase as t...

Underground coal mining activities are prone to cause movement and breakage in geological strata and also lead to mining subsidence and even ground fissures. Along the direction working panel advancing, ground fissures may occur in roof in front and/or behind working panel. However, the investigations of previous similarity tests in lab only emphasize on the region behind working panel. By impr...

This paper experimentally investigates the fatigue damage evolution in pre-corroded aluminum alloy (AA) 7075-T7651 via digital image correlation (DIC) and scanning electron microscopy (SEM). Three stages of including accumulation, macro-crack initiation propagation are identified described combined analysis severity curves strain maps. The micro-cracking characteristics dominant fracture region...

The purpose of this research is to determine the resistance to the stress corrosion cracking (SCC) of three unidirectional (pultruded) E-glass/polymer composites based on modified polyester, epoxy and vinyl ester resins. The composites have been subjected to a nitric acid solution of pH 1.2 in a newly designed four-point bend fixture. The stress corrosion process was initiated on the as supplie...

In this paper an analytical crack propagation scenario is proposed which assumes that a crack propagates in the tooth root in both the crack depth direction and the tooth width direction, and which is more reasonable and realistic for non-uniform load distribution cases than the other presented scenarios. An analytical approach is used for quantifying the loss of time-varying gear mesh stiffnes...