Weight Function Analysis of Interface Cracks: Mismatch Versus Oscillation

1991 ◽  
Vol 58 (4) ◽  
pp. 931-938 ◽  
Author(s):  
Huajian Gao
Keyword(s):  
Weight Function ◽  
Interface Crack ◽  
Function Method ◽  
Function Analysis ◽  
Dissimilar Materials ◽  
Global Scale ◽  
Oscillatory Behavior ◽  
Intensity Factors ◽  
Fundamental Understanding

This paper has two goals. First, it is aimed at providing a fundamental understanding of the oscillatory behavior of an interface crack between two dissimilar materials from the viewpoint of the interface mismatch that results from the cracking. Second, we extend the Bueckner-Rice weight function method to facilitate the interface crack analysis. Using properties of the surface Green’s functions of a homogeneous solid and solutions obtained from weight function formulae, a mismatch analysis is carried out which indicates that the local mismatch near the crack tip results in the oscillatory near-tip field while the mismatch on the global scale leads to the corresponding stress intensity factors. For an oscillatory interface crack field, it is shown that, other than a few extra material constants, the interface weight function analysis is completely parallel to the well-developed homogeneous theory so that knowledge of one crack solution for a given bimaterial geometry is sufficient for determination of solutions under any other loading conditions.

Comparison of Different Methods for the Determination of Stress Intensity Factors of Cracks in Pipes With Stress Gradients

1984 ◽  
Vol 106 (2) ◽  
pp. 209-213 ◽  
Author(s):  
C. Mattheck ◽  
P. Morawietz ◽  
D. Munz ◽  
H. Stamm
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Weight Function ◽  
Excellent Agreement ◽  
Stress Intensity Factors ◽  
Function Method ◽  
Weight Functions ◽  
Intensity Factors ◽  
Stress Gradients

Stress intensity factors for long longitudinal and complete circumferential cracks under stress gradients were calculated using a weight function method. The weight functions were obtained by a method proposed by Petroski and Achenbach [3] and by a finite element fit procedure. Excellent agreement was obtained with finite element results of Labbens, et al. [7].

Reliability Evaluation of Flip Chip Using Stress Intensity Factors of an Interface Crack

2003 ◽  
Author(s):  
Won-Keun Kim ◽  
Toru Ikeda ◽  
Noriyuki Miyazaki
Keyword(s):  
Stress Intensity ◽  
Interface Crack ◽  
Stress Intensity Factors ◽  
Flip Chip ◽  
Liquid Crystal Display ◽  
Dissimilar Materials ◽  
Circuit Board ◽  
Electrical Performance ◽  
Intensity Factors ◽  
Adhesive Film

Anisotropic Conductive Adhesive Film (ACF) has been used for electronic assemblies such as the connection between a Liquid Crystal Display (LCD) panel and a flexible print circuit board (FPC). ACF is expected to be a key technology for flip chip packaging and chip size packaging. The goal of our work is to provide an optimum design scheme to achieve the best combination of electrical performance and mechanical reliability for electronic packages using the ACF. This study presents an evaluation technology for the delamination of the ACF connections. We utilized the stress intensity factors of an interface crack between jointed dissimilar materials. The evaluation technology presented herein was found to provide reliability of an electronic package using the ACF connection during the solder reflow process.

scholarly journals Crack Paralleling an Interface Between Dissimilar Materials

1987 ◽  
Vol 54 (4) ◽  
pp. 828-832 ◽  
Author(s):  
J. W. Hutchinson ◽  
M. E. Mear ◽  
J. R. Rice
Keyword(s):  
Stress Intensity ◽  
Interface Crack ◽  
Stress Intensity Factors ◽  
Dissimilar Materials ◽  
Complex Stress ◽  
External Loading ◽  
Universal Relation ◽  
Intensity Factors ◽  
Elastic Solids ◽  
Complex Stress Intensity Factor

A crack paralleling a bonded plane interface between two dissimilar isotropic elastic solids is considered. When the distance of the crack from the interface is small compared to the crack length itself and to other length scales characterizing the geometry, a simple universal relation exists between the Mode I and Mode II stress intensity factors and the complex stress intensity factor associated with the corresponding problem for the crack lying on the interface. In other words, if the influence of external loading and geometry on the interface crack is known, then this information can immediately be used to generate the stress intensity factors for the sub-interface crack. Conditions for cracks to propagate near and parallel to, but not along, an interface are derived.

A Method to Extract Interface Stress Intensity Factors Using Interlayers

2005 ◽  
Author(s):  
Sridhar Santhanam
Keyword(s):  
Stress Intensity ◽  
Interface Crack ◽  
Stress Intensity Factors ◽  
Crack Problem ◽  
Interface Stress ◽  
Mode I ◽  
Universal Relation ◽  
Intensity Factors ◽  
Infinite Blocks

A method is presented here to extract stress intensity factors for interface cracks in plane bimaterial fracture problems. The method relies on considering a companion problem wherein a very thin elastic interlayer is artificially inserted between the two material regions of the original bimaterial problem. The crack in the companion problem is located in the middle of the interlayer with its tip located within the homogeneous interlayer material. When the thickness of the interlayer is small compared with the other length scales of the problem, a universal relation can be established between the actual interface stress intensity factors at the crack tip for the original problem and the mode I and II stress intensity factors associated with the companion problem. The universal relation is determined by formulating and solving a boundary value problem. This universal relation now allows the determination of the stress intensity factors for a generic plane interface crack problem as follows. For a given interface crack problem, the companion problem is formulated and solved using the finite element method. Mode I and II stress intensity factors are obtained using the modified virtual crack closure method. The universal relation is next used to obtain the corresponding interface stress intensity factors for the original interface crack problem. An example problem involving a finite interface crack between two semi-infinite blocks is considered for which analytical solutions exist. It is shown that the method described above provides very acceptable results.

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