Effects of Preexisting Stress Voids on Electromigration Stress Buildup and Flux Divergence

1999 ◽  
Vol 563 ◽  
Author(s):  
Y. -L. Shen ◽  
C. A. Minor ◽  
Y. L. Guo
Keyword(s):  
Stress Field ◽  
Stress Profile ◽  
Flux Divergence ◽  
Element Analysis ◽  
One Dimensional ◽  
Atomic Flux ◽  
The Finite Element Analysis ◽  
The One ◽  
Aluminum Interconnects ◽  
Stress Buildup

AbstractNumerical modeling of electromigration stress buildup and flux divergence was undertaken. The objective is to provide a mechanistic understanding of the question: Do preexisting stress voids grow during later electromigration, to become potentially fatal? Conflicting experimental results have been reported. In this work the stress field in aluminum interconnects containing voids was first quantified using the finite element analysis. The averaged stress field then served as the initial condition in the one-dimensional partial differential equation of electromigration stress buildup. The finite difference method was employed to solve the evolving stress profile and the associated atomic flux and flux divergence along the conducting line. It was found that a large preexisting void suffers greater flux divergence and is therefore more prone to growth during electromigration. A single large stress void is more detrimental than populous small voids. Published experimental observations seem to support these findings.

Modeling Electromigration-Induced Stress Buildup Due to Nonuniform Temperature

1994 ◽  
Vol 338 ◽  
Author(s):  
J. J. Clement ◽  
C. V. Thompson ◽  
A. Enver
Keyword(s):  
Integrated Circuits ◽  
Driving Force ◽  
Stress Evolution ◽  
Nonuniform Temperature ◽  
Flux Divergence ◽  
Atomic Transport ◽  
Atomic Flux ◽  
Induced Stress ◽  
Interconnect Lines ◽  
Stress Buildup

ABSTRACTAtomic transport due to electromigration in interconnect lines in integrated circuits depends strongly on temperature. Therefore temperature nonuniformities can create sites of atomic flux divergence resulting in material accumulation or depletion leading to failure. The mechanical stress which will evolve at the sites of material flux divergence will oppose the electromigration driving force. A model is developed to describe the stress evolution during electromigration in the presence of temperature nonuniformnities. Solutions of the differential equations describing the electromigration-induced stress buildup are calculated numerically. The solutions are compared to experimental data in the literature.

Thermo-mechanical analyses of beryllium compound refractive lens for NSLS-II beamline

2011 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
V. Ravindranath ◽  
S. Sharma ◽  
O. Chubar ◽  
Y. Cai ◽  
S. Coburn
Keyword(s):  
Peak Power ◽  
Thermal Strain ◽  
Total Power ◽  
Element Analysis ◽  
One Dimensional ◽  
X Ray Scattering ◽  
Insertion Device ◽  
The Finite Element Analysis ◽  
Refractive Lens ◽  
Synchrotron Light

In this paper we discuss the finite-element analysis (FEA) of a one-dimensional beryllium compound refractive lens (Be-CRL) that was undertaken to study the feasibility of installing the CRL in the Inelastic X-ray Scattering (IXS) beamline of National Synchrotron Light Source-II (NSLS-II) (a new state-of-the-art medium-energy third-generation storage ring). The current insertion device for this beamline is an IVU22-6m in-vacuum planar undulator delivering a total power of ~9 kW with a peak power density of ~90 kW/mrad2. Through analysis, based on calculation of spectral angular distribution of undulator radiation from IVU22, we determined that it is essential to install a 30 µm graphite filter upstream of the CRL in order to restrict the temperature rise in the CRL to 65°C for acceptable thermal strain.

scholarly journals Study of one-dimensional cure simulation applicable conditions for thick laminates and its comparison with three-dimensional simulation

2018 ◽  
Vol 25 (6) ◽  
pp. 1197-1204 ◽  
Author(s):  
Mingfa Ren ◽  
Qi Wang ◽  
Jie Cong ◽  
Xin Chang
Keyword(s):  
Computational Cost ◽  
Three Dimensional ◽  
Cure Kinetics ◽  
Transient Heat Conduction ◽  
Material System ◽  
Element Analysis ◽  
One Dimensional ◽  
Dimensional Simulation ◽  
The One ◽  
Three Dimensional Finite Element

AbstractThe comparison of one- and three-dimensional cure simulation of thick thermoset matrix laminates was conducted in this study. The applicable conditions of one-dimensional cure simulation were investigated. The transient heat conduction equation coupled to the cure kinetics was solved numerically using one- and three-dimensional finite element analysis. The evolution of temperature and degree of cure of the laminates during the curing process obtained by the simulation agreed well with the published experimental results. The results indicate that a wider one-dimensional analysis applicable region around the center point will be obtained in the laminate with a higher span-to-thickness ratio and in a less anisotropic material system. In the applicable region, the accuracy of the one-dimensional cure simulation can satisfy the engineering request and save the computational cost. While beyond the region, there is a steep increase in deviation of the one- and three-dimensional simulation results.

Mechanical Properties of a One-Way Beam String Structure with the Cooperation of the Supporting Structure

2010 ◽  
Vol 163-167 ◽  
pp. 701-707
Author(s):  
Yun Jing Nie ◽  
Tie Ying Li
Keyword(s):  
Mechanical Properties ◽  
Analysis Software ◽  
Element Analysis ◽  
Single Beam ◽  
Supporting Structure ◽  
Practical Project ◽  
The Finite Element Analysis ◽  
String Structure ◽  
The One ◽  
Load Conditions

In this paper, taking a practical project for the study, using the finite element analysis software ANSYS, static analyses under different load conditions are performed on a single beam string structure (BSS) and a one-way beam string structure with the cooperation of the supporting structure, respectively. Moreover, influence of factors on mechanical properties of the one-way BSS with the cooperation of the supporting structure is investigated. The factors include grouting, support form, corrosion. The results can provide a reference for design and construction of the same type of structure.

Mechanical Behavior of Hollow Steel-Concrete Composite Columns with Perforated Ribs

2011 ◽  
Vol 255-260 ◽  
pp. 619-623
Author(s):  
Yao Zeng ◽  
Chong Wu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Bearing Capacity ◽  
The Other ◽  
Element Analysis ◽  
Composite Columns ◽  
The Finite Element Analysis ◽  
The One ◽  
Relationship Of

Two different specimens of hollow composite columns with perforated ribs, one is the column with double steel skin and the other is with single steel skin, were designed for imposing axial compression test. The tests indicated that both of the columns have a good bearing capacity and the column with double steel skin has a comparatively better bearing capacity than the one with single steel skin. Then comparisons between tests and finite element analysis (FEA) were preceded, which showed that not only the load-displacement relationship of the columns, but also a reasonable failure mode can be simulated by the finite element analysis.

Stress Field in Finite Width Axisymmetric Wound Rolls

2001 ◽  
Vol 69 (2) ◽  
pp. 130-138 ◽  
Author(s):  
Y. M. Lee ◽  
J. A. Wickert
Keyword(s):  
Stress Field ◽  
Mixed Boundary ◽  
Nonlinear Material ◽  
Shear Stresses ◽  
Finite Width ◽  
Web Interface ◽  
Element Analysis ◽  
One Dimensional ◽  
The Core ◽  
The Web

A model is developed for predicting the stress field within a wound roll of web material, in which the radial, circumferential, transverse, and shear stresses can vary in both the roll’s radial and cross-web (transverse) directions. As has been the case in previous wound roll stress analyses based on one-dimensional models, the present approach accounts for the anisotropic and nonlinear material properties of the layered web material, and the incremental manner in which the roll is wound. In addition, the present development accounts for arbitrary cross-sectional geometry and material of the core, and the presence of nonuniform tension across the web’s width during winding. The solution is developed through an axisymmetric, two-dimensional, finite element analysis which couples individual models of the core and layered web region substructures. The core’s stiffness matrix at the core-web interface provides a mixed boundary condition for the web region’s first layer. In several parameter studies, variations of the stress components in the roll’s radial and cross-width directions are discussed and compared with predictions of the simpler companion one-dimensional model. The character of the stress field at the web region’s free edges and along the core-web interface, and the possibility of stress concentration or singularity existing there, are also discussed.

scholarly journals The solution of the plane problem of the theory of elasticity by the boundary elements method

2020 ◽  
Vol 211 ◽  
pp. 02021
Author(s):  
Mykola Surianinov ◽  
Yurii Krutii ◽  
Anatolii Kovrov ◽  
Vladimir Osadchiy
Keyword(s):  
Plane Problem ◽  
Boundary Elements ◽  
Theory Of Elasticity ◽  
Element Analysis ◽  
One Dimensional ◽  
Method Of Boundary Elements ◽  
Boundary Elements Method ◽  
Numerical Analytical Method ◽  
The Green Function ◽  
The One

An approach to solving the biharmonic equation of the plane problem of the theory of elasticity by the numerical-analytical method of boundary elements is developed. The reduction of the two-dimensional problem to the one-dimensional one was carried out by the KantorovichVlasov method. Systems of fundamental orthonormal functions and the Green function are constructed without any restrictions on the nature of the boundary conditions. A numerical example of solving a plane problem by the boundary element method for a rectangular plate is considered. The results are compared with the data of finite element analysis in the ANSYS program and those obtained by A.V. Aleksandrov.

Application of the Eigenstrain Theory to Predict Residual Stress around Curved Edges after Laser Shock Peening

2013 ◽  
Vol 768-769 ◽  
pp. 185-192 ◽  
Author(s):  
Stefano Coratella ◽  
M. Burak Toparli ◽  
Michael E. Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Laser Shock Peening ◽  
Stress Profile ◽  
Laser Shock ◽  
Element Analysis ◽  
Residual Stress Profile ◽  
The Finite Element Analysis ◽  
Treatment Technologies ◽  
Shock Peening

Residual stresses play a fundamental role in mechanical engineering. They can be generated by manufacturing processes or introduced purposely by surface treatment technologies. One of the most recent technologies developed to introduce residual stresses is Laser Shock Peening. Since it is a relatively expensive technology, a fundamental role is played by the Finite Element Analysis approach to predict the final residual stress profile. The FEA approach consists of either direct simulation of the LSP process or the application of the eigenstrain approach. The application of the eigenstrain theory in predicting residual stresses after LSP treatment in curved edges is the subject of this research.

Numerical Simulation of Stress Field of PRMMC Caused by Current Impulse

2011 ◽  
Vol 211-212 ◽  
pp. 555-560
Author(s):  
Rong Xin Guo ◽  
Hai Ting Xia ◽  
Bang Cheng Yang ◽  
Le Hui Huang ◽  
Feng Yan
Keyword(s):  
Stress Field ◽  
Random Distribution ◽  
Volume Fraction ◽  
Cell Model ◽  
Matrix Composites ◽  
Current Field ◽  
Element Analysis ◽  
Current Impulse ◽  
The Finite Element Analysis ◽  
Analysis Platform

In this paper, based on the finite element analysis platform ANSYS, the stress field of particle reinforced metal matrix composites (PRMMC) caused by current impulse has been simulated. The cube cell model and multi-particle random distribution cell model are used in this simulation. The current field, temperature field and stress field of PRMMC caused by current impulse are given. The influence of material character of PRMMC, number or volume fraction of the particles in cell model, particles shape and distance on those fields is analyzed.

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