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Mayfield West, Australia

Mostafavi S.S.,University of New South Wales | Zhang L.C.,University of New South Wales | Lunn J.,Bradken
Key Engineering Materials | Year: 2010

Edge chipping by an indenter has been used to investigate the fragmentation of brittle materials. This paper proposed a constitutive model for studying both the initiation and propagation of cracks during the chipping of concrete. The analysis was carried out by the finite element method using a commercially available code, LS-DYNA. The results showed that a zone with very high compressive stresses appears beneath the indenter and causes the material to break or crush. Most of the external work, about 78%, was dissipated in the crushing zone while only a small percentage (less than 17%) contributed to form chips/fragments. As the indentation proceeded, radian-median cracks initiated and propagated downward and parallel to the front surface of the material to form a half penny crack. The crack tips from both sides of the indenter on the surface would then deviate toward the free edge, leading to a chipping scallop at a critical load. © (2010) Trans Tech Publications, Switzerland.

Sivaneri N.T.,West Virginia University | Kavipurapu P.,Bradken
54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference | Year: 2013

The dynamic response of simply supported glass/epoxy composite beams subjected to moving loads in a hygrothermal environment is carried out using the general purpose finite element program ANSYS. The moving load model and the hygrothermal incorporation are validated separately by reproducing results available in the literature. The hygrothermal effect is introduced by using empirical relations for degrading the material stiffness properties of the matrix. The corresponding ply properties are calculated using the rule of mixtures. A parametric study is conducted by varying the fiber volume fraction and the fiber orientation of the angle plies in the laminate. The results indicate that the dynamic magnification factors generally increase due to hygrothermal effects but all the laminates considered do not behave in a similar manner. Thus it is possible to minimize the environmental effect by judiciously selecting the laminate configuration. © 2013 by Nithi Sivaneri.

Wu X.,Bradken | Wu X.,Shanxi Normal University | Wang F.,Shanxi Normal University | Wang C.,Shanxi Normal University
Journal of Magnetism and Magnetic Materials | Year: 2015

The magnetic properties and reversal process of L10-FePt/Fe and L10-FePt exchange coupled graded nanodots were investigated using the object-oriented micromagnetic framework (OOMMF). It is indicated that the increase in anisotropy gradient span of L10-FePt section is favorable for the reduction in coercivity for L10-FePt/Fe graded nanodots. However, the low remanence magnetization and squareness ratio caused by the large gradient span is not popular for recording media. If the Fe soft section is removed, the low coercivity and high squareness ratio can be achieved simultaneously for L10-FePt graded nanodots with an appropriate gradient design. Therefore, the combination of exchange coupled graded structure and bit patterned media is an effective approach to balance the trilemma issues of current perpendicular magnetic recording media. © 2015 Elsevier B.V. All rights reserved.

David D.,Steel Founders Society of America | Monroe R.,Steel Founders Society of America | Thomas E.,Bradken
Welding Journal | Year: 2015

AWS B2.1, D1.6, and a stringent standard such as ASME Boiler and Pressure Vessel Code ( BPVC). Section IX recognize cast grades and allow the use of the same Welding Procedure Specification (WPS) as other similar steels in other product forms. AWS D1.1 should add cast grades. Its users can use prequalified WPS. The WPS is a document specifying how the welding process must be done to ensure sound and quality welds. These standards identify cast carbon grades as Groups I and II in their base metal grouping. The mechanical properties of these cast grades are also comparable to the prequalified base metals. Both ASME BPVC Section IX and ASTM A488 allow the qualification of welding of castings using wrought steel in the same P-number group.

Yao Q.,University of New South Wales | Zhang L.C.,University of New South Wales | Bao R.,University of New South Wales | Lunn J.,Bradken | Melmeth C.,Bradken
Key Engineering Materials | Year: 2010

This paper investigates experimentally the edge chipping of a rock to assess the cutting performance of a conical and a pyramidal tip. It was found that the conical tip generates many radiated cracks and results in a larger amount of fine rock grains due to crashing. The size of chips produced by the pyramidal tip is bigger. It was concluded that the critical chipping energy has approximately a linear relation with h9/4 of which h is the depth of cut of the tip. © (2010) Trans Tech Publications, Switzerland.

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