Numerical Analysis of Three-Dimensional Semi-Elliptical Interfacial Cracks Subjected to Indentation Load

2014 ◽  
Vol 627 ◽  
pp. 289-292 ◽  
Author(s):  
N. Kurihara ◽  
Masayuki Arai
Keyword(s):  
Fracture Toughness ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Interfacial Crack ◽  
Indentation Test ◽  
Interfacial Fracture ◽  
Indentation Load ◽  
J Integral ◽  
Interfacial Fracture Toughness ◽  
Interfacial Cracks

The aim of this study is to show elastic J-integral needed to evaluate the interfacial fracture toughness of bi-material in indentation test. Three dimensional J-integrals along the crack front tip in semi-elliptical crack lying on the interface were analyzed using domain integral technique installed in commercialized finite element code MARC. The J-integral was calculated under several kind of aspect ratio of semi-elliptical cracks. In order to have to evaluate the interfacial fracture toughness from interfacial crack length and indentation load obtained in indentation tests, the analytical formula for two dimensional interfacial crack J-integral under plane stress, which had been introduced by J. R. Rice and G. C. Sih, was modified in reflecting upon the three dimensional effect. Finally, the indentation test was conducted for Aluminum alloy/ PMMA combination sample, and the associated fracture toughness was evaluated.Fig.1 Schematic illustration of indentation testFig.2 Schematic illustration of analysis mode

scholarly journals Design Equations for Mixed-Mode Fracture of Dental Ceramic-cement Interfaces Using the Brazil-nut-sandwich Test

2021 ◽  
pp. 1-33
Author(s):  
David Manan ◽  
Jeongho Kim ◽  
Renata Marques de Melo ◽  
Yu Zhang
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Interfacial Fracture ◽  
Mixed Mode Fracture ◽  
Interfacial Fracture Toughness ◽  
Brazil Nut ◽  
Modulus Ratio ◽  
Dental Ceramic ◽  
Interfacial Cracks ◽  
Practical Guidance

Abstract Dental interfaces are subject to mixed-mode loading. This study provides a practical guidance for determining interfacial fracture toughness of dental ceramic systems. We address interfacial fracture of a composite resin cement sandwiched between two dental ceramic materials. Emphasis is placed on sandwich disc specimens with cracks originating from elliptical-shaped flaws near the center, for which analytical fracture mechanics methods fail to predict. The interaction integral method is used to provide accurate finite element solutions for cracks with elliptical-shaped flaws in a Brazil-nut-sandwich specimen. The developed model was first validated with existing experimental data, and then used to evaluate three most widely used dental ceramic systems: polycrystalline ceramics (zirconia), glass-ceramics (lithium disilicate), and feldspathic ceramics (porcelain). Contrary to disc specimens with ideal cracks, those with cracks emanating from elliptical-shaped flaws do not exhibit a monotonic increase in interfacial toughness. Also, interfacial fracture toughness is seen to have a direct relationship with the aspect ratio of elliptical-shaped flaws and an inverse relationship with the modulus ratio of the constituents. The presence of an elliptical-shaped flaw significantly changes the interfacial fracture behavior of sandwich structures. Semi-empirical design equations are provided for fracture toughness and stress intensity factors for interfacial cracks. The developed design equations provide a practical guidance for determining interfacial fracture toughness of selected dental ceramic material systems. Those equations take into account four critical factors: size of the elliptical flaw, modulus ratio of constituent materials, loading angle and applied load.

Elasto-Plastic Analysis of the Peel Test for Thin Film Adhesion

1988 ◽  
Vol 110 (3) ◽  
pp. 266-273 ◽  
Author(s):  
Kyung-Suk Kim ◽  
Junglhl Kim
Keyword(s):  
Fracture Toughness ◽  
Interfacial Crack ◽  
Peel Test ◽  
Interfacial Fracture ◽  
Peel Strength ◽  
Interfacial Fracture Toughness ◽  
Cu Films ◽  
Film Adhesion ◽  
Thin Film Adhesion ◽  
Elastoplastic Bending

Analyses have been made to extract the objective interfacial fracture toughness from the peel strength of very thin metallic films. An elastoplastic bending model of the adherend film has been employed in the analyses applying the fracture mechanics concept of steady-state interfacial crack growth. The analytic result finally shown is a universal peel diagram where the objective interfacial fracture toughness is readily readable when the peel strength is known. Experimental results for Cu films on Si and polyimide substrate systems with a Cr interface are also presented.

scholarly journals Solutions and Discussions of thin film Undergoing the Nonlinear Peeling

2003 ◽  
Vol 795 ◽  
Author(s):  
Yueguang Wei ◽  
Siqi Shu ◽  
Ying Du LNM
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Effective Strain ◽  
Slope Angle ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness ◽  
Element Analysis ◽  
Von Mises

ABSTRACTBased on the bending model, three double-parameter criteria characterizing thin film peeling process are introduced and analyzed in detail. Three double-parameter criteria include: (1) the interfacial fracture toughness and the separation strength, (2) the interfacial fracture toughness and the interfacial crack tip slope angle of thin film, and (3) the interfacial fracture toughness and the critical von Mises effective strain of thin film at crack tip. Based on the three double-parameter criteria, the thin film nonlinear peeling problems are solved analytically for each case. The results show that the solutions of thin film nonlinear peeling based on the bending model are very sensitive to the model parameter selections. Through analyses and comparisons for different solutions, a connection between solutions based on the bending models and based on the two-dimensional elastic-plastic finite element analysis is obtained.

Current Activities for Standardization of Test Method for Interfacial Fracture Toughness of Thermal Spray Coatings in Japan

2013 ◽  
Vol 577-578 ◽  
pp. 149-152
Author(s):  
Masayuki Arai ◽  
Yasuhiro Yamazaki ◽  
Masato Suzuki ◽  
Yukio Miyashita ◽  
H. Waki
Keyword(s):  
Fracture Toughness ◽  
Thermal Spray ◽  
Indentation Test ◽  
Hardness Test ◽  
Interfacial Fracture ◽  
Standard Test ◽  
Test Method ◽  
Test Machine ◽  
Interfacial Fracture Toughness ◽  
Spray Coatings

Collaborative research has been conducted by the Japan Thermal Spray Society (JTSS) to establish a standard test method for evaluating the interfacial fracture toughness of thermal sprayed coatings, including thermal barrier coatings. The test method is based upon the indentation test method utilizing a conventional Vickers hardness test machine. In this committee, round robin tests were performed to check differences in the evaluated results among collaborators. This paper reports on the progress of such activity in Japan.

scholarly journals Evaluation of the Interfacial Fracture Toughness of Anodic Bonds

2007 ◽  
Vol 73 (735) ◽  
pp. 1266-1272 ◽  
Author(s):  
Yoshiaki NOMURA ◽  
Masaki NAGAI ◽  
Toru IKEDA ◽  
Noriyuki MIYAZAKI
Keyword(s):  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness
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