Comparison of Fundamental Frequency and Sweep Resistance of Different Wire Loops Using Finite Element Model

2015 ◽  
Vol 15 (01) ◽  
pp. 1450032 ◽  
Author(s):  
Yun Chen ◽  
Fuliang Wang
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
High Speed ◽  
Element Model ◽  
Microelectronic Packaging ◽  
Fe Model ◽  
Wire Loop ◽  
Loop Design ◽  
Loop Shape ◽  
The Wire

Wire loop resistance is critical for microelectronic packaging because it directly influences the reliability of the product. Proposed herein is an effective method for predicting the resistance of a wire loop. A finite element (FE) model is developed for verifying the method. The wire geometry is modeled based on actual wire profiles captured with a high-speed camera. Based on this model, the effects of wire properties, residual stresses, loop shape and loop type on the wire loop resistance are studied. Simulations demonstrated that the shape of the loop could dramatically alter the wire loop resistance. On the other hand, the wire properties, residual stresses and loop type mildly affect the wire loop resistance. The standard loop is the more resistant loop than the N and M loops. By using a large and hard wire, moderately tensioning the wire loop and reducing the loop span, height and number of kinks, one can improve the wire loop resistance. This study should provide useful insights into loop design for modern microelectronic packaging.

An assessment of the Sachs method for measuring residual stresses in cold worked fastener holes

1998 ◽  
Vol 33 (4) ◽  
pp. 263-274 ◽  
Author(s):  
D J Smith ◽  
C G C Poussard ◽  
M J Pavier
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Cold Working ◽  
Element Model ◽  
Fe Model ◽  
Working Process ◽  
Element Analysis ◽  
Near Surface ◽  
Cold Worked ◽  
Good Agreement

Measurements of residual stresses in 6 mm thick aluminium alloy 2024 plates containing 4 per cent cold worked fastener are made using the Sachs method. The measurements are made on discs extracted from the plates. The measured tangential residual stress distribution adjacent to the hole edge are found to be affected by the disc diameter. The measured residual stresses are also in good agreement with averaged through-thickness predictions of residual stresses from an axisymmetric finite element (FE) model of the cold working process. A finite element analysis is also conducted to simulate disc extraction and then the Sachs method. The measured FE residual stresses from the Sachs simulation are found to be in good agreement with the averaged through-thickness predicted residual stresses. The Sachs simulation was not able to reproduce the detailed near-surface residual stresses found from the finite element model of the cold working process.

scholarly journals Effect of Torsional Element towards High-Speed Rotating Shaft’s Critical Speed at Different Boundary Conditions

2019 ◽  
Vol 8 (4) ◽  
pp. 6787-6792
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
High Speed ◽  
Critical Speed ◽  
Element Model ◽  
Accurate Estimation ◽  
Fe Model ◽  
Rotating Shaft ◽  
Different Boundary Conditions ◽  
The Difference

Efficiency improvement that can be provided by the high-speed rotating equipment becomes a concern for designers nowadays. Since the high-speed rotating machinery was capable of rotating at very near to critical speed, the accurate estimation of critical speed needs to be considered. This paper investigated the effect of torsional element towards critical speed of high-speed rotating shaft system for pinned-pinned (P-P), clamped-free (C-F) and clamped-free (C-F) boundaries condition. The Nelson’s finite element model that considers the torsional effect was developed for formulating the finite element (FE) model. This FE model was used to derive Mathieu-Hill’s equation and then solved by applying the Bolotin’s theory. From the solution, the Campbell’s diagram of the high-speed shaft was plotted. It was found that torsional motion has significant effect on the critical speed for different boundary conditions. The difference between critical speed of 4DOF and 5DOF models can be as high as 6.91 %.

Effect of Process Routing on Machining Deformation for Multi-Frame Double Sided Monolithic Components

2010 ◽  
Vol 97-101 ◽  
pp. 2894-2897 ◽  
Author(s):  
Zhi Tao Tang ◽  
Zhan Qiang Liu ◽  
Li Qiang Xu
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Coordinate Measuring Machine ◽  
Element Model ◽  
Fe Model ◽  
Clamping Force ◽  
Optimal Process ◽  
Machining Deformation ◽  
Measuring Machine ◽  
Monolithic Components

When machining aerospace monolithic components, a severe deformation can be observed due to the release and redistribution of the original residual stresses, together with the action of cutting loads and clamping force. In this paper, a finite element model predicting machining deformation was developed considering the above mentioned multi-factors coupling effects. Based on the model, the effect of process routing on machining deformation for multi-frame double sided monolithic components was studied. To validate the FE model, true frame components were machined and deformations were measured on a Coordinate Measuring Machine. The result revealed that the prediction model is credible. At last the paper puts forwards optimal process routing based on minimizing the machining deformation.

Effect Residual Stress on Material Hardness by Finite Element Simulation during the Process of High Speed Cutting

2016 ◽  
Vol 719 ◽  
pp. 23-27
Author(s):  
De Weng Tang ◽  
Zhi Feng He ◽  
Xi Jian Lv ◽  
Cong Peng
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
High Speed ◽  
Cutting Temperature ◽  
Element Model ◽  
Residual Tensile Stress ◽  
Machined Surface ◽  
High Speed Cutting ◽  
Material Hardness

Residual stresses induced during the process of high speed cutting are very critical due to safety and corrosion resistance. Based on the nonlinear finite element code DEFORM, thermodynamic couple model of residual stress was built. Effect distribution of residual stresses on three different materials physical properties of hardness are analyzed by using the finite element model during the process of high speed cutting. The results show that metal material hardness is the key factors to residual stress. When materials’ hardness is higher, residual tensile stress is easy to form on the machined surface due to high cutting temperature, such as hardened steel SKD11(HRC=62). To lower hardness material, residual compressive stress is generated on the machined surface for plastic deformation, such as softer materials 7075Al (HRC=23).

Controlling and Optimization of Steering Wheel Shimmy of the Vehicle at High-Speed Based on FEA Method

2014 ◽  
Vol 574 ◽  
pp. 247-252
Author(s):  
Zong Bin Huang ◽  
Bing Xu ◽  
Zhao Hui Hu ◽  
Zhi Cheng He ◽  
Xiong Sheng Chen
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Plate Thickness ◽  
Element Model ◽  
Steering System ◽  
System Structure ◽  
Steering Wheel ◽  
Fe Model ◽  
Successful Solution ◽  
Wheel Shimmy

In this paper, finite element method was adopted to solve the Steering wheel shimmy problem. Firstly, finite element model of the whole steering system from the knuckle to the steering wheel is conducted, and be verified by test. After modeling and verification, it is possible for the FE model to identify a natural frequency that contributes reasonably to the shimmy phenomenon in the steering wheel. Secondly the frequency spectrum of acceleration which is obtained based on test is loaded at the knuckle to simulate steering wheel shimmy. Finally, the sequential quadratic programming is performed to optimize steering system structure and improve the isolation performance based on this model. The plate thickness and stiffness of bushing are set as discrete optimization variables, and the Y-direction acceleration of steering wheel at 12 o'clock is set as the objective function. The successful solution of the steering wheel shimmy of a passenger car proves that this method is efficacious.

scholarly journals Numerical Evaluation of Advanced Laser Control Strategies Influence on Residual Stresses for Laser Powder Bed Fusion Systems

2020 ◽  
Vol 9 (4) ◽  
pp. 435-445
Author(s):  
Massimo Carraturo ◽  
Brandon Lane ◽  
Ho Yeung ◽  
Stefan Kollmannsberger ◽  
Alessandro Reali ◽  
...  
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Laser Power ◽  
High Speed ◽  
Control Strategies ◽  
Element Model ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Element Analysis ◽  
Powder Bed

AbstractProcess-dependent residual stresses are one of the main burdens to a widespread adoption of laser powder bed fusion technology in industry. Residual stresses are directly influenced by process parameters, such as laser path, laser power, and speed. In this work, the influence of various scan speed and laser power control strategies on residual stresses is investigated. A set of nine different laser scan patterns is printed by means of a selective laser melting process on a bare plate of nickel superalloy 625 (IN625). A finite element model is experimentally validated comparing the simulated melt pool areas with high-speed thermal camera in situ measurements. Finite element analysis is then used to evaluate residual stresses for the nine different laser scan control strategies, in order to identify the strategy which minimizes the residual stress magnitude. Numerical results show that a constant power density scan strategy appears the most effective to reduce residual stresses in the considered domain.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Predicting the High Speed Cutting Process of Titanium Alloy by Finite Element Method

2011 ◽  
Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Process ◽  
Fe Model ◽  
Dry Cutting ◽  
Friction Coefficients ◽  
Machining Conditions

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

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