A controlled crack growth was achieved in single edge—cracked specimens made of a high—molecular weight PNNA by regulating the cross— head speed of loading of the specimens by a computer—driven testing device. The crosshead speeds used during the tests were varied between v =1x107m/s and 1X1O5m/s. 5 It was shown that in this area of very slow quasi—static loading of brittle plexiglas specimens ...

Purpose: In the present paper a crack arrest model is proposed for an infinitely long narrow poled piezoelectric strip embedded with a centrally situated finite hairline straight crack. Design/methodology/approach: The ceramic of the strip is assumed to be mechanically brittle and electrically ductile. Combined mechanical and electrical loads applied at the edge of the strip open the rims of th...

Department of Mechanics of Materials, School of Mechanical Engineering, Hanoi University of Science and Technology, No. 1, Dai Co Viet Road, Hanoi, Viet Nam b International Research Center for Computational Materials Science, Hanoi University of Science and Technology, No. 1, Dai Co Viet Road, Hanoi, Viet Nam Department of Engineering Science and Mechanics, M/C 0219, Virginia Polytechnic Instit...

The study of brittle or fatigue fracture that involves contact along the crack faces is difficult for several reasons. On the one hand, material data pertaining to the growth of cracks in a compressive environment are scant, and, on the other, frictional stresses may be transmitted across the contacting crack faces. The analysis of cracks under these conditions is complicated. Nevertheless, sol...

Background and Aim: Preparation of root canal with rotary nickel-titanium (NiTi) instruments may potentially create microcracks that can lead to vertical root fracture. This study aimed to compare the incidence of crack formation by BioRaCe and Edge Taper Platinum systems in the mesiobuccal canals of extracted first mandibular molars. Materials and Methods: In this experimental study, 50 first...