The purpose of the present study is to examine the relationship between the supportive designs of proximal region of zirconia framework on the fracture load. The zirconia frameworks with four different supportive designs on the proximal region were fabricated and classified with their radiuses of curvature (R): R=0.5 mm, R=1.0 mm, R=1.5 mm, and R=2.0 mm. The zirconia frameworks were conditioned...

Collagen is considered to be the principal contributor of postyield properties. Any modification of bone collagen including accumulation of non-enzymatic cross-links should, therefore, be expected to modify the fracture behavior of bone. Previous studies under monotonic loading to fracture have shown that non-enzymatic glycation (NEG) of bone reduces its post-yield properties [1,2], but no info...

Molecular dynamics (MD) simulations are used to directly observe nucleation of median cracks in oxide glasses under indentation. Indenters with sharp angles can nucleate median cracks in samples with no pre-existing flaws, while indenters with larger indenter angles cannot. Increasing the tip radius increases the critical load for nucleation of the median crack. Based upon an independent set of...

Present study deals with the prediction of crack initiation angle for mixed mode (I/II) fracture using finite element techniques and J-Integral based approach. The FE code ANSYS is used to estimate the stress intensity factor numerically. The estimated values of SIF were incorporated into six different crack initiation angle criteria to predict the crack initiation angle. Single edge crack spec...

This paper deals with the application of Cohesive Zone Model (CZM) concepts to study mode I fracture in adhesive bonded joints. In particular, an intrinsic piece-wise linear cohesive surface relation is used in order to model fracture in a pre-cracked bonded Double Cantilever Beam (DCB) specimen. Finite element implementation of the CZM is accomplished by means of the user element (UEL) feature...

In this paper a new method to determine the fracture properties and strain energy release rate for Carbon- Polyester composite has been introduced.  Fracture characteristics such as critical stress intensity factor and critical strain energy release rate for mode I, mode II and mixed mode loading were determined using Arcan type specimen. 130 layers of carbon fiber polyester woven composite wit...

In this paper, using energy method, small scale effects on the buckling analysis of a double-walled carbon nanotube (DWCNT) under external radial pressure is studied. The constitutive equations derived for a DWCNT using the nonlocal theory of elasticity which Eringen are presented for the first time. By minimizing the second variation of the total energy for a DWCNT, hence, the value of the non...

in this study, the process-based watershed model, soil and water assessment tool (swat), was used for simulating hydrology and sediment transport in the gharesou watershed and for identifying critical areas of soil erosion and water pollution. after model calibration and uncertainty analysis using sufi-2 (sequential uncertainty fitting, ver. 2) method, the outputs of the calibrated model were u...

A combined experimental/analytical work is carried out to elucidate the fracture resistance of a thin, hard coating bonded to a semi-infinite substrate due to indentation by a cylindrical surface. The bending of the coating under the softer substrate induces concentrated tensile stress regions at the lower and upper surfaces of the coating, from which cracks may ensue. The evolution of such dam...