scholarly journals Effect of Substrate Compliance on Measuring Delamination Properties of Elastic Thin Foil

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
C. Liu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Model Problem ◽  
Hot Isostatic Pressing ◽  
Interfacial Crack ◽  
Interfacial Strength ◽  
Thin Foil ◽  
Bulge Test ◽  
Thin Elastic Plate

Through the analysis of a model problem, a thin elastic plate bonded to an elastic foundation, we address several issues related to the miniature bulge test for measuring the energy-release rate associated with the interfacial fracture of a bimaterial system, where one of the constituents is a thin foil. These issues include the effect of the substrate compliance on the interpretation of the energy release rate, interfacial strength, and the identification of the boundary of the deforming bulge or the location of the interfacial crack front. The analysis also suggests a way for measuring the so-called foundation modulus, which characterizes the property of the substrate. An experimental example, a stainless steel thin foil bonded to an aluminum substrate through hot-isostatic-pressing (HIP), is used to illustrate and highlight some of the conclusions of the model analysis.

Miniature bulge test and energy release rate in HIPed aluminum/aluminum interfacial fracture

2018 ◽  
Vol 120 ◽  
pp. 179-198 ◽  
Author(s):  
C. Liu ◽  
M.L. Lovato ◽  
K.D. Clarke ◽  
D.J. Alexander ◽  
W.R. Blumenthal
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Interfacial Fracture ◽  
Bulge Test

Effect of Characteristic Parameters of Exponential Cohesive Zone Model on Mode I Fracture of Laminated Composites

2012 ◽  
Vol 525-526 ◽  
pp. 409-412 ◽  
Author(s):  
Guo Wei Zhu ◽  
Yu Xi Jia ◽  
Peng Qu ◽  
Jia Qi Nie ◽  
Yun Li Guo
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Laminated Composites ◽  
Peak Load ◽  
Interfacial Strength ◽  
Critical Energy ◽  
Mode I ◽  
Zone Model ◽  
Critical Energy Release Rate

Delamination is a particularly dangerous damage mode of high performance laminated composites. In order to describe the composites ductile cracking and its progressive evolution accurately, the adjusted exponential cohesive zone model (CZM) is adopted, which correlates the tensile traction with the corresponding interfacial separation along the fracturing interfacial zone. At first the adjusted exponential CZM is used to simulate the mode I delamination of the standard double cantilever beam (DCB). The simulated results are in good agreement with the corrected beam theory and the corresponding experimental results. Then in order to research how the interfacial properties influence the mode I fracture, the interfacial strength and the critical energy release rate are studied. The main results are obtained as follows. The interfacial strength plays a crucial role in the laminated composites delamination onset, and it affects the peak load significantly if there is not a pre-crack. Once the delamination propagation begins to occur in the laminated composites, the responses of the load-displacement plots are relatively insensitive to the interfacial strength, and only the critical energy release rate is of critical importance. Furthermore, the peak load increases with the increase of the critical energy release rate and interfacial strength.

scholarly journals The crack kinking out of an interface

2005 ◽  
Vol 32 (3) ◽  
pp. 209-221 ◽  
Author(s):  
Jelena Veljkovic
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Interfacial Crack ◽  
Intensity Factors ◽  
Elastic Materials ◽  
Kinked Cracks ◽  
Compliant Material ◽  
Stiff Material ◽  
Plane Strain Crack

Kinking of a plane strain crack out of an interface between the two dissimilar isotropic elastic materials is analyzed. Analysis is focused on the initiation of kinking and thus the segment of the crack leaving the interface is imagined to be short compared to the segment in the interface. The analysis provides the stress intensity factors and energy release rate of the kinked cracks in terms of the corresponding quantities for the interfacial crack. The energy release rate is enhanced if the crack heads into the more compliant material and is diminished if the crack kinks into the stiff material.

scholarly journals Analytical Energy Release Rate of Interfacial Crack in Composite Laminates

2019 ◽  
Vol 37 (1) ◽  
pp. 137-142
Author(s):  
Weiling Zheng ◽  
Longxi Zheng
Keyword(s):  
Finite Element ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Composite Laminates ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Beam Theory ◽  
Three Point Bending ◽  
The Right

In order to study whether the interfacial crack will grow or not in the composite laminates, the energy release rate of a crack in three-point bending model was obtained by using the Timoshenko beam theory and local generalized forces. The results of energy release rate were validated by the finite element results. The results indicate that the energy release rate of left crack tip is equal to that of the right crack tip when the crack before the crack goes cross the loading point; after the crack goes cross the loading point, the energy release rate of the left crack tip increases and then decreases gradually, while the energy release rate of right crack tip decreases first and increases later; the energy release rate of left crack tip is equal to that of the right crack tip again when the crack is symmetric with the loading point.

Study of Interfacial Delamination by Considering the Effect of Temperature and Moisture during Solder Reflow for QFN Package

2005 ◽  
Vol 2 (3) ◽  
pp. 197-207
Author(s):  
Fu-Mauh Wong ◽  
K.N Seetharamu
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Interfacial Crack ◽  
Strain Energy Release ◽  
Geometrical Parameters ◽  
High Tendency ◽  
Solder Reflow

Experiment has been conducted to measure the solubility Csat of mold compound and to obtain the moisture weight loss curves at various temperature. Moisture desorption modeling has been conducted to calculate the moisture diffusivity for desorption D(T) by matching with the experimental results. Finite Element Analysis (FEA) has also been conducted to calculate the transient development of strain energy release rate (ERR) at the interfacial crack tip due to thermal stress only (Gt), hygrostress only (Gh), and the combined effect (Gtotal) during solder reflow. ERR is computed based on the Virtual Crack Closure Technique (VCCT). It is found that Gh is significantly smaller than Gt, however the effect of hygrostress significantly increases the total strain energy release rate when combined with the thermal effect. The maximum Gtotal occurs at the peak of the solder reflow profile. The effects of crack size and geometrical parameters have been studied. The result imply that the interfacial crack is unstable and has a high tendency of growing to a significant extent. ERR is strongly influenced by the thickness of the package while length between the edge of die and pad has a moderate affect on the ERR.

scholarly journals Analytical Fracture Mechanics Analysis of the Pull-Out Test Including the Effects of Friction and Thermal Stresses

2000 ◽  
Vol 9 (6) ◽  
pp. 096369350000900 ◽  
Author(s):  
John A. Nairn
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Thermal Stresses ◽  
Interfacial Crack ◽  
Single Fibre ◽  
Finite Elements Analysis ◽  
Accurate Analysis ◽  
Pull Out ◽  
Microbond Test

The energy release rate for propagation of a debond in a single-fibre pull out test was derived analytically. The key finding was that an accurate analysis can be derived by a global energy analysis that includes effects of residual stresses and interfacial friction but does not need to include the details of the stress state at the interfacial crack tip. By comparison to finite elements analysis, it was verified that the analytical results are very accurate provided the debond tip is not too close to either end of the specimen. By casting the results in terms of net-specimen stress, it was possible to derive a general energy release rate result that applies to both the pull-out test and the related microbond test. The energy release rate expressions can be used to determine interfacial fracture toughness from single-fibre pull-out tests or microbond tests.

The Strain Energy Release Rate of a Bi-Material Beam with Interfacial Crack

2006 ◽  
Vol 306-308 ◽  
pp. 369-374 ◽  
Author(s):  
Shiuh Chuan Her ◽  
Wei-Bo Su
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Layer Structure ◽  
Interfacial Crack ◽  
Beam Theory ◽  
Strain Energy Release ◽  
Before And After

Multi-layer structures are common in electronic package especially for the micro devices manufactured via the semi-conductor processes or MEMS processes. Interfacial crack due to the delamination significantly weakens the multi-layer structure. It is desired to understand the interfacial fracture properties of the electronic packaging materials. In this research, three specimens named Doubled Cantilever Beam (DCB), End-Notched Flexure (ENF), and Four-Point-Bending are proposed to investigate the fracture toughness associated with mode I, mode II and mixed mode. Basing on the Euler-Bernoulli beam theory, the strain energy in a bi-layer beam is derived. The strain energy before and after the propagation of the interfacial crack are calculated, lead to the determination of the strain energy release rate. The analytical results of strain energy release rate derived in this investigation are compared with the numerical results obtained from finite element method. The effects of material properties and thickness between the adjacent layers of interfacial crack are examined through the parametric study.

scholarly journals Influence of temperature on behavior of the interfacial crack between the two layers

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 259-268 ◽  
Author(s):  
Jelena Djokovic ◽  
Ruzica Nikolic ◽  
Srdjan Tadic
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Room Temperature ◽  
Environmental Temperature ◽  
Interfacial Crack ◽  
Uniform Temperature ◽  
Influence Of Temperature On ◽  
Thickness Variations ◽  
Distribution Of Stresses

In this paper is considered a problem of the semi-infinite crack at the interface between the two elastic isotropic layers in conditions of the environmental temperature change. The energy release rate needed for the crack growth along the interface was determined, for the case when the two-layered sample is cooled from the temperature of the layers joining down to the room temperature. It was noticed that the energy release rate increases with the temperature difference increase. In the paper is also presented the distribution of stresses in layers as a function of the temperature and the layers? thickness variations. Analysis is limited to the case when the bimaterial sample is exposed to uniform temperature.

Sign in / Sign up

Export Citation Format

Share Document