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.

Reliability Simulation of Cu/Polymer interface in Fan-out Wafer Level Packaging

2020 ◽  
Vol 2020 (1) ◽  
pp. 000094-000099
Author(s):  
Yuji Okada ◽  
Atsushi Fujii ◽  
Kenta Ono ◽  
Yoshiharu Kariya
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Thermal Stresses ◽  
Material Selection ◽  
Basic Material ◽  
Model Structure ◽  
Critical Energy Release Rate ◽  
Interlayer Dielectric ◽  
Polymer Interface

Abstract In order to improve the performance and reliability of the package, the interlayer dielectric (Polymer) must not be delaminated and materials should not fracture due to thermal stresses during the operation or the manufacturing process. If the reliability of the package can be known in advance by simulation, it can be expected to greatly help in material selection and package design. Firstly, we created material-specific master curves (time–temperature superposition) by considering the measurement results of the Peel Test at the Cu/Polymer interface and the mechanical properties of polymer. The critical Energy Release Rate (𝒢𝒸) could be calculated by its master curve. Secondary, we calculated the Energy Release Rate (𝒢) from Finite Element Analysis (FEA) in the package model structure. Finally, delamination is judged by normalizing 𝒢/𝒢𝒸. This study has made it possible to simulate the delamination possibility of Cu/Polymer interface at arbitrary temperatures and displacement rates from basic material data and FEA analysis of the package model structure.

scholarly journals Study of Strain-Hardening Behaviour of Fibre-Reinforced Alkali-Activated Fly Ash Cement

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4015
Author(s):  
Hyuk Lee ◽  
Vanissorn Vimonsatit ◽  
Priyan Mendis ◽  
Ayman Nassif
Keyword(s):  
Fly Ash ◽  
Energy Release Rate ◽  
Strain Hardening ◽  
Energy Release ◽  
Release Rate ◽  
Critical Energy ◽  
Critical Energy Release Rate ◽  
Pull Out ◽  
Alkali Activated ◽  
Alkali Activated Cement

This paper presents a study of parameters affecting the fibre pull out capacity and strain-hardening behaviour of fibre-reinforced alkali-activated cement composite (AAC). Fly ash is a common aluminosilicate source in AAC and was used in this study to create fly ash based AAC. Based on a numerical study using Taguchi’s design of experiment (DOE) approach, the effect of parameters on the fibre pull out capacity was identified. The fibre pull out force between the AAC matrix and the fibre depends greatly on the fibre diameter and embedded length. The fibre pull out test was conducted on alkali-activated cement with a capacity in a range of 0.8 to 1.0 MPa. The strain-hardening behaviour of alkali-activated cement was determined based on its compressive and flexural strengths. While achieving the strain-hardening behaviour of the AAC composite, the compressive strength decreases, and fine materials in the composite contribute to decreasing in the flexural strength and strain capacity. The composite critical energy release rate in AAC matrix was determined to be approximately 0.01 kJ/m 2 based on a nanoindentation approach. The results of the flexural performance indicate that the critical energy release rate of alkali-activated cement matrix should be less than 0.01 kJ/m 2 to achieve the strain-hardening behaviour.

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.

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.

scholarly journals Energy release rate in the presence of residual and thermal stresses

2015 ◽  
Vol 59 ◽  
pp. 73-78 ◽  
Author(s):  
Jeong Soon Park ◽  
Young Hwan Choi ◽  
Jungdo Kim ◽  
Seyoung Im
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Thermal Stresses

Numerical Study on Adhesive Interface Reinforcement of Piezoelectric Composite under Impact Load

2011 ◽  
Vol 117-119 ◽  
pp. 849-857
Author(s):  
Rui Xiang Bai ◽  
Liang Wang
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Mechanical Load ◽  
Impact Load ◽  
Numerical Study ◽  
Piezoelectric Composite ◽  
Interfacial Toughness ◽  
Pull Out ◽  
Fiber Bridging

The interfacial reinforcement with interlaminar chopped fibers of piezoelectric composite under impact electro-mechanical load was studied using nonlinear finite element method. A meso- mechanical model based on the main toughness reinforcement mechanism of single fiber bridging and pull out was adopted, and then a tri-linear bridging law was obtained, while the interface chopped fibers by defining nonlinear bidirectional spring elements between coincident nodes on the two crack surfaces within bridging zone and the energy release rate was calculated using the virtual crack closure technique. The numerical investigation indicates that the interlaminar chopped fiber can effectively reduce the crack tip energy release rate whether the applied voltage is positive or negative, which was an effective technique improve the interfacial toughness of the piezoelectric composite adhesive structure.

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