Experiments and numerical simulations of microelectronic devices subjected to multipoint impact loading

2021 ◽  
Vol 127 ◽  
pp. 114408
Author(s):  
Xi-huang Zhang ◽  
Jin-zhu Li ◽  
Feng Qin ◽  
Lin Wang
Keyword(s):  
Numerical Simulations ◽  
Impact Loading ◽  
Microelectronic Devices

scholarly journals Comparison of Damage Models in Numerical Simulations of Fillet Welds under Quasi-static and Impact Loading

2017 ◽  
Vol 197 ◽  
pp. 79-88
Author(s):  
E.L. Grimsmo ◽  
L.E.B. Dæhli ◽  
O.S. Hopperstad ◽  
A. Aalberg ◽  
M. Langseth ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Impact Loading ◽  
Fillet Welds ◽  
Damage Models

scholarly journals Crashworthiness of Inflatable Thin-Walled Structures for Impact Absorption

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Cezary Graczykowski ◽  
Jan Holnicki-Szulc
Keyword(s):  
Numerical Simulations ◽  
Impact Loading ◽  
Mechanical Characteristics ◽  
Pressure Control ◽  
Thin Walled Structures ◽  
Compressed Gas ◽  
Thin Walled ◽  
Crash Characteristics ◽  
The Impact ◽  
Impact Absorption

The paper describes application of innovative, inflatable thin-walled structures for absorption of the impact loading and thoroughly investigates their crash characteristics. The proposed concept assumes inflation of thin-walled structures with compressed gas of appropriately adjusted pressure in order to improve their basic mechanical properties, enhance energy dissipation capabilities, and increase corresponding durability to impact loading. In the first part of the paper the influence of compressed gas on mechanical characteristics of aluminium beverage can is analysed experimentally and by the corresponding numerical simulations. The following section proposes and numerically verifies three diverse engineering applications of inflatable thin-walled structures for impact absorption. Finally, the last part introduces the concept of adaptive inflatable barrier and briefly presents three simple strategies of pressure control. Both the performed basic experiment and the conducted numerical simulations show the advantageous influence of compressed gas and prove the feasibility of using inflatable thin-walled structures for impact absorption.

Real-Time Detection and Explicit Finite Element Simulation of Delamination in Composite Laminates Under Impact Loading

2000 ◽  
Author(s):  
K. Minnaar ◽  
M. Zhou
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Real Time ◽  
Impact Loading ◽  
Matrix Cracking ◽  
Laser Vibrometer ◽  
Zone Model ◽  
Elastic Model ◽  
Damage Initiation ◽  
The Impact

Abstract A new experimental technique is developed to determine the onset and evolution of delamination in fiber-reinforced composites under impact loading. The configuration uses a split-Hopkinson bar for low-velocity impact loading and two Polytec laser vibrometer systems for real-time monitoring of the initiation and progression of delamination. The experiment allows the histories of load, displacement, and velocity of impacted specimens to be recorded and analyzed. The recorded profiles are used to characterize the damage initiation and evolution in the laminate. Numerical simulations are conducted using a cohesive finite element method. The method employs a cohesive zone model to simulate matrix cracking and interlaminar delamination and a transversely isotropic, elastic model to characterize the bulk behavior of each ply. The simulations provide time-resolved characterization of damage during the impact loading. The damage modes predicted by the numerical simulations agree well with experimental observations.

Characterization of Sputtered Films using the Scanning Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 44-45
Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Sputtered Films ◽  
Plasma Sputtering ◽  
Microelectronic Devices ◽  
Control Film ◽  
Scanning Electron

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.

Ion Beam Induced Interfacial Reactions in Molybdenum Thin Films on Silicon

1981 ◽  
Vol 39 ◽  
pp. 162-163
Author(s):  
L. J. Chen ◽  
L. S. Hung ◽  
J. W. Mayer
Keyword(s):  
Ion Beam ◽  
Chemical Vapor ◽  
Interfacial Reactions ◽  
Practical Applications ◽  
Microelectronic Devices ◽  
Recent Emergence ◽  
Chemical Vapor Deposited ◽  
Atomic Mixing ◽  
Silicon Interface ◽  
Kinetics Of

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.

Saturation mechanism and generated viscosity in gravito-turbulent accretion disks

2020 ◽  
Vol 640 ◽  
pp. A53
Author(s):  
L. Löhnert ◽  
S. Krätschmer ◽  
A. G. Peeters
Keyword(s):  
Growth Rate ◽  
Numerical Simulations ◽  
Accretion Disks ◽  
Gravitational Instability ◽  
Turbulent Viscosity ◽  
Radial Distance ◽  
Maximum Growth ◽  
Wave Number ◽  
Radiative Cooling ◽  
Mixing Length

Here, we address the turbulent dynamics of the gravitational instability in accretion disks, retaining both radiative cooling and irradiation. Due to radiative cooling, the disk is unstable for all values of the Toomre parameter, and an accurate estimate of the maximum growth rate is derived analytically. A detailed study of the turbulent spectra shows a rapid decay with an azimuthal wave number stronger than ky−3, whereas the spectrum is more broad in the radial direction and shows a scaling in the range kx−3 to kx−2. The radial component of the radial velocity profile consists of a superposition of shocks of different heights, and is similar to that found in Burgers’ turbulence. Assuming saturation occurs through nonlinear wave steepening leading to shock formation, we developed a mixing-length model in which the typical length scale is related to the average radial distance between shocks. Furthermore, since the numerical simulations show that linear drive is necessary in order to sustain turbulence, we used the growth rate of the most unstable mode to estimate the typical timescale. The mixing-length model that was obtained agrees well with numerical simulations. The model gives an analytic expression for the turbulent viscosity as a function of the Toomre parameter and cooling time. It predicts that relevant values of α = 10−3 can be obtained in disks that have a Toomre parameter as high as Q ≈ 10.

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