Hydraulically pumped cone fracture in bilayers with brittle coatings
نویسندگان
چکیده
An earlier finite element modeling analysis of inner cone cracks in monolithic brittle solids subject to cyclic indentation in liquids is extended to include the case of a brittle layer bonded to a compliant substrate, using a model glass/polycarbonate bilayer system as an illustrative case study. Provision is made for incorporation of plate flexure stresses, along with hydraulic pumping stresses, into the Hertzian contact field. Tensile flexure stresses ultimately accelerate inner cone cracks through the lower halves of the glass plates to unstable failure. The analysis accounts for the experimentally observed trends in the inner cone crack evolution in cyclic contact fatigue. 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
منابع مشابه
Role of core support material in veneer failure of brittle layer structures.
A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin ba...
متن کاملHydraulically pumped cone fracture in brittle solids
An analysis of inner cone cracks in brittle solids subject to cyclic indentation in liquid is presented. These inner cone cracks, so named because they form well within the maximum contact circle, are postulated to be driven by a hydraulic pumping mechanism. Unlike their more traditional outer cone crack counterparts, inner cones do not appear in monotonic loading or even cyclic loading in the ...
متن کاملMulti-crack analysis of hydraulically pumped cone fracture in brittle solids under cyclic spherical contact
The evolution of surface damage in bilayers due to cyclic spherical indentation in the presence of incompressible lubricant is studied using an all-transparent glass/polycarbonate system as amodel formore practical applications such as dental crowns and rolling contact fatigue. In situ observations and post-mortem material sectioning reveal that inner cone cracks evolve sequentially from the co...
متن کاملCracking of porcelain coatings bonded to metal substrates of different modulus and hardness
A preceding study of contact damage in a bilayer system consisting of a porcelain coating on a stiff Pd-alloy substrate is here expanded to investigate the role of substrate modulus and hardness. Bilayers are made by fusing the same dental porcelain onto Co-, Pd-, and Au-alloy metal bases. Indentations are made on the porcelain surfaces using spheres of radii 2.38 and 3.98 mm. Critical loads to...
متن کاملCracking of brittle coatings adhesively bonded to substrates of unlike modulus
The role of elastic mismatch in determining critical conditions for indentation fracture in brittle coatings on substrates of unlike modulus was investigated. A model transparent trilayer system, consisting of a glass coating layer bonded to a thick substrate of different glass or polymer by a thin layer of epoxy adhesive, facilitated in situ observations of crack initiation and propagation. A ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006