journal article·2007-06-18

Influences of complex loading and margin geometry: failure of curved brittle layer structures

Tarek Qasim

International Journal of Fracture· Volume 144· Issue 1
Publisher page

Abstract

This study investigates the influences of off-axis loading and of margin geometry on “margins failure” observed in loaded curved bi-layer structures, away from the contact loading point. Specimens of hemispherical bi-layer model consist of glass shells with varying margins geometry, and filled with epoxy resin substrate are prepared. These specimens are loaded with compliant PTFE Teflon cylindrical indenters, with a modulus of several orders of magnitude lower than the indented materials. Load is applied normally; axisymmetric to the dome apex, and at 45° from the axis of symmetry. In this fashion, the effect of off-axis loading and the influence of margin geometry on “margins failure” are studied. The onset of fracture is observed in situ using a video camera system. Finite element analysis is applied to determine basic stress distribution within the dome structures, and to confirm a shift in maximum tensile stress from the near-contact area to the dome sides with the use of more compliant indenters. Critical loads to initiate radial cracks and damage evolution are presented, and interpreted with the results of FEA.
Source: openaire · Quality: candidate unverified · Source record ↗

Research context

OpenAlex topics: Mechanical Behavior of Composites · Structural Response to Dynamic Loads · Structural Analysis of Composite Materials

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (25)

Show source-provided references
1. Qasim T, Ford C, Bush M and Hu X-Z (2006). Contact damage in brittle curved coatings: the influence of indenter/coating modulus mismatches. Key Eng Mater 312: 369–37410.4028/www.scientific.net/KEM.312.369 ↗
2. Thompson JY, Anusavice KJ, Naman A and Morris HF (1994). Fracture Surface Characterization of Clinically Failed All-Ceramic Crowns. J Dental Res 73: 1824–183210.1177/00220345940730120601 ↗
3. Malament KA and Socransky SS (1999a). Survival of Dicor glass-ceramic dental restorations over 14 years: I. Survival of Dicor complete coverage restorations and effect of internal surface acid etching, tooth position, gender and age. J Prosthetic Dentistry 81: 23–3210.1016/S0022-3913(99)70231-3 ↗
4. Malament KA and Socransky SS (1999b). Survival of Dicor glass-ceramic dental restorations over 14 years: II. Effect of thickness of Dicor material and design of tooth preparation. J Prosthetic Dentistry 81: 662–66710.1016/S0022-3913(99)70104-6 ↗
5. Malament KA and Socransky SS (2001). Survival of Dicor glass-ceramic dental restorations over 16 years: Part III: effect of luting agent and tooth or tooth- substitute core structure. J Prosthetic Dentistry 86: 511–51910.1067/mpr.2001.119415 ↗
6. Qasim T, Ford C, Bush M, Hu X-Z, Lawn B and Malament K (2007a). Margin failure in brittle dome structures: relevance to failure of dental crowns. J Biomed Mater Res: Part B-Appl Biomater 80B: 78–8510.1002/jbm.b.30571 ↗
7. Qasim T, Bush M and Hu X-Z (2004b). A numerical/experimental study of contact damage in non-planar porcelain/metal bi-layers. Int J Mech Sci 46: 827–84010.1016/j.ijmecsci.2004.06.004 ↗
8. Chai H, Lawn BR and Wuttiphan S (1999). Fracture modes in brittle coatings with large interlayer modulus mismatch. J Mater Res 14: 3805–381710.1557/JMR.1999.0514 ↗
9. Zhao H, Hu X and Bush M (2000). Contact damage in porcelain/Pd-alloy bilayers. J Mater Res 15: 676–8210.1557/JMR.2000.0100 ↗
10. Lawn BR, Deng Y, Miranda P, Pajares A, Chai H and Kim DK (2002). Overview: damage in brittle layer structures from concentrated loads. J Mater Res 17: 3019–303610.1557/JMR.2002.0440 ↗
11. Rudas M, Qasim T, Bush M and Lawn B (2005). Failure of curved brittle layer systems from radial cracking in concentrated surface loading. J Mater Res 20(10): 2812–281910.1557/JMR.2005.0343 ↗
12. Lawn BR, Lee KS, Chai H, Pajares A, Kim DK and Wuttiphan S (2000a). Damage-resistant brittle coatings. Adv Eng Mater 2: 745–74810.1002/1527-2648(200011)2:11<745::AID-ADEM745>3.0.CO;2-E ↗
13. Jung YG, Wuttiphan S, Peterson IM and Lawn BR (1999). Damage modes in dental layer structures. J Dental Res 78: 887–89710.1177/00220345990780040901 ↗
14. Lawn BR, Lee KS, Chai H, Pajares A, Kim DK, Wuttiphan S, Peterson IM and Hu X (2000b). Damage-resistant brittle coatings. Adv Eng Mater 2: 745–74810.1002/1527-2648(200011)2:11<745::AID-ADEM745>3.0.CO;2-E ↗
15. Qasim T, Bush M, Hu X-Z and Lawn B (2004a). Contact damage in brittle coating layers: influence of surface curvature. J Biomed Mater Res: Part B-Appl Biomater 73B: 179–18510.1002/jbm.b.30188 ↗
16. Chai H and Lawn BR (2004). Fracture Mode Transitions in Brittle Coating Layers on Compliant Substrates as a Function of Thickness. J Mater Res 19: 1752–176110.1557/JMR.2004.0219 ↗
17. Qasim T, Ford C, Bush M and Hu X-Z (2004c). Effect of indenter size on critical conditions for contact damage in planar and non-planar bi-layers. Strength Frac Complexity 2: 81–93
18. Zhao H, Hu X, Bush MB and Lawn BR (2001). Cracking of porcelain coatings bonded to metal substrates of different modulus and hardness. J Mater Res 16: 1471–147810.1557/JMR.2001.0205 ↗
19. Qasim T, Ford C, Bush M and Hu X-Z (2007b). The influence of margin geometry on failure in brittle coatings on compliant substrate: Relevance to failure of dental crowns. Key Eng Mater 334–335: 573–57610.4028/www.scientific.net/KEM.334-335.573 ↗
20. Qasim T, Ford C, Bush M, Hu X-Z and Lawn B (2005). Effect of off-axis concentrated loading on failure of curved brittle layer structures. J Biomed Mater Res: Part B-Appl Biomater 76B: 334–33910.1002/jbm.b.30373 ↗
21. Lee C-S, Lawn BR and Kim DK (2001). Effect of tangential loading on critical conditions for radial cracking in brittle coatings. J Am Ceram Soc 84: 2719–272110.1111/j.1151-2916.2001.tb01081.x ↗
22. Lawn BR, Deng Y and Thompson VP (2001). Use of contact testing in the characterization and design of all-ceramic crown-like layer structures: A review. J Prosthetic Dentistry 86: 495–51010.1067/mpr.2001.119581 ↗
23. Zhang Y and Brian L (2004). Long term strength of ceramics for biomedical applications. J Biomed Mater Res 69B: 166–17210.1002/jbm.b.20039 ↗
24. Zhang Y, Bhowmich S and Lawn B (2005). Competing fracture modes in brittle materials subject to concentrated cyclic loading in liquid environments: Monoliths. J Mater Res 20: 2021–202910.1557/JMR.2005.0276 ↗
25. Bhowmich S, Zhang Y and Lawn B (2005). Competing fracture modes in brittle materials subject to concentrated cyclic loading in liquid environments: Bi-layer structures. J Mater Res 20: 2792–280010.1557/JMR.2005.0335 ↗