Nanomechanical Response of Materials and Thin Film Systems: Finite Element Simulation

1994 ◽  
Vol 356 ◽  
Author(s):  
S.A. Syed Asif ◽  
B. Derby ◽  
S.G. Roberts
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Contact Area ◽  
Considerable Error ◽  
Element Simulation ◽  
Pile Up ◽  
Simulation Results ◽  
Hardness Response

AbstractFinite element simulation of the nanoindentation process has been carried out to investigate the nanomechanical response of materials and thin film systems. The influence of the geometry of the indenter, friction between the indenter and the surface, and pre-stress in the film, on the nanomechanical response have all been investigated. The effect of pile-up on the contact area calculation and the problems which occur with the commonly used methods in calculating the contact area have been studied. Results shows considerable error in calculating the contact area which depends on the indentation conditions used for the simulation. Simulation results suggest, that the influence of residual stress on hardness response is material sensitive.

Simulation research on low frequency sound absorption of monostable metamaterials

2021 ◽  
Vol 263 (6) ◽  
pp. 648-652
Author(s):  
Tuo Xing ◽  
Xianhui Li ◽  
Xiaoling Gai ◽  
Zenong Cai ◽  
Xiwen Guan
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Theoretical Model ◽  
Finite Element Simulation ◽  
Sound Absorption ◽  
Magnetic Force ◽  
Low Frequency ◽  
Low Frequencies ◽  
Element Simulation ◽  
Simulation Results

The monostable acoustic metamaterial is realized by placing a flexible panel with a magnetic proof mass in a symmetric magnetic field. The theoretical model of monostable metamaterials has been proposed. The method of finite element simulation is used to verify the theoretical model. The magnetic force of the symmetrical magnetic field is simplified as the relationship between force and displacement, acting on the mass. The simulation results show that as the external magnetic force increases, the peak sound absorption shifts to low frequencies. The theoretical and finite element simulation results are in good agreement.

Nanoscale thermal mapping of few-layer organic crystals

CrystEngComm ◽  
2019 ◽  
Vol 21 (36) ◽  
pp. 5402-5409
Author(s):  
Ying Zhang ◽  
Cong Zhang ◽  
Dacheng Wei ◽  
Xue Bai ◽  
Xiangfan Xu
Keyword(s):  
Thin Film ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Organic Crystals ◽  
Organic Thin Film ◽  
Thermal Mapping ◽  
Element Simulation

Combining a scanning thermal microscope with a finite element simulation, the conductivity of an organic thin-film can be quantitatively detected.

scholarly journals Piezoelectric Two Layer Plate for Position Stabilization

2012 ◽  
Author(s):  
Martin Krause ◽  
Daniel Steinert ◽  
Eric Starke ◽  
Uwe Marschner ◽  
Günther Pfeifer ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Network Model ◽  
Inertial Frame ◽  
System Simulation ◽  
Simulation And Optimization ◽  
Laboratory Setup ◽  
Element Simulation ◽  
Rigid Connection ◽  
Simulation Results

Numerous vibrating electromechanical systems miss a rigid connection to the inertial frame. An artificial inertial frame can be generated by a shaker which compensates for vibrations. In this paper we present an encapsulated and perforated unimorph bending plate for this purpose. As basis for system simulation and optimization a new 3-port multi domain network model was derived. An extension of the network allows the simulation of the acoustical behavior inside the capsule. Network parameters are determined using Finite Element simulations. The dynamic behavior of the network model agrees with the Finite Element simulation results up to the first resonance of the system. The network model was verified by measurements on a laboratory setup, too.

Optimization and performance analysis of magnetorheological fluid damper considering different piston configurations

2019 ◽  
Vol 30 (5) ◽  
pp. 764-777 ◽  
Author(s):  
Song-lin Nie ◽  
De-kui Xin ◽  
Hui Ji ◽  
Fang-long Yin
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Structural Parameters ◽  
Magnetorheological Fluid ◽  
Magnetorheological Damper ◽  
Magnetorheological Dampers ◽  
Magnetorheological Fluid Damper ◽  
Element Simulation ◽  
Fluid Damper ◽  
Simulation Results

This article presents the design and multi-physics coupling analysis of a shear-valve-mode magnetorheological fluid damper with different piston configurations. The finite element model is built to study the effects of the shape of the piston slot and magnetism-insulators at both ends of the piston yoke on the performance of the magnetorheological damper. Particle swarm optimization and finite element simulation are combined to optimize the structural parameters of the magnetorheological damper. The influences of different piston configurations on the magnetic flux density in the working gap, the shear stress, the viscous stress, and the dynamic range are investigated. The simulation results reveal that the magnetorheological damper, in which the corners of the piston slot are chamfered and the edges of the magnetism-insulators are filleted, exhibits a better damping performance. Furthermore, magnetorheological dampers with and without magnetism-insulators are fabricated. The influences of control current, displacement, and velocity on the mechanical performance of the magnetorheological dampers are experimentally investigated, and the experiment results are in accordance with the theoretical derivation and finite element simulation results.

Finite Element Simulation of Welding of Large Structures

1992 ◽  
Vol 114 (4) ◽  
pp. 441-451 ◽  
Author(s):  
S. Brown ◽  
H. Song
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Welding Distortion ◽  
Surrounding Structure ◽  
Element Simulation ◽  
Weld Distortion ◽  
Welding Processes

Current simulations of welding distortion and residual stress have considered only the local weld zone. A large elastic structure surrounding a weld, however, can couple with the welding operation to produce a final weld state much different from that resulting when a smaller structure is welded. The effect of this coupling between structure and weld has the potential of dominating the final weld distortion and residual stress state. This paper employs both two-and three-dimensional finite element models of a circular cylinder and stiffening ring structure to investigate the interaction of a large structure on weld parameters such as weld gap clearance (fitup) and fixturing. The finite element simulation considers the full thermo-mechanical problem, uncoupling the thermal from the mechanical analysis. The thermal analysis uses temperature-dependent material properties, including latent heat and nonlinear heat convection and radiation boundary conditions. The mechanical analysis uses a thermal-elastic-plastic constitutive model and an element “birth” procedure to simulate the deposition of weld material. The effect of variations of weld gap clearance, fixture positions, and fixture types on residual stress states and distortion are examined. The results of these analyses indicate that this coupling effect with the surrounding structure should be included in numerical simulations of welding processes, and that full three-dimensional models are essential in predicting welding distortion. Elastic coupling with the surrounding structure, weld fitup, and fixturing are found to control residual stresses, creating substantial variations in highest principal and hydrostatic stresses in the weld region. The position and type of fixture are shown to be primary determinants of weld distortion.

Packaging Induced Die Stress Characterization Using van der Pauw Sensors Between −180°C and 80°C

2014 ◽  
Vol 2014 (1) ◽  
pp. 000483-000487
Author(s):  
Uday S. Goteti ◽  
Francy J. Akkara ◽  
Richard C. Jaeger ◽  
Michael C. Hamilton ◽  
Jeffrey C. Suhling
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Temperature Effects ◽  
Temperature Range ◽  
Stress Sensors ◽  
Element Simulation ◽  
Die Stress ◽  
Simulation Results ◽  
Van Der Pauw

Packaging-induced die-stresses due to temperature effects on various materials of the package are characterized using piezoresistive van der Pauw stress sensors over a temperature range of −180° C to 80° C. Piezo-resistive coefficients extracted previously are then used to obtain a mapping between change in resistance and corresponding stress at all tested temperatures. The obtained values of stress are compared with finite element simulation results.

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