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.

scholarly journals Determination of Directional Residual Stresses by the Contour Method

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1104 ◽  
Author(s):  
Josef Hodek ◽  
Antonín Prantl ◽  
Jan Džugan ◽  
Pavel Strunz
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Electrical Discharge Machine ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Material Model ◽  
Element Model ◽  
Contour Method ◽  
Diffraction Measurement ◽  
Measuring Machine

This study evaluated residual stresses in heat-treated specimens made of 316L stainless steel using FE analysis and compared them with stresses determined by the contour method. Contour method is usually used just for evaluation of residual stresses that are normal to the cut plan. In the current study this approach is extended and both normal and tangential stresses are determined. The specimens were cut using wire electrical discharge machine and the contours of the cut were measured using a coordinate measuring machine. The prior treatment of the specimens was simulated using the finite-element method. An appropriate boundary condition and temperature-dependent material model were employed. The finite-element model was validated against neutron-diffraction measurement data. The results showed a good agreement in normal and tangential directions of stress.

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.

Optimization of Bulkhead Processing Sequence for Multi-Frame Monolithic Components by FEM

2007 ◽  
Vol 24-25 ◽  
pp. 355-360 ◽  
Author(s):  
Zhi Tao Tang ◽  
Zhan Qiang Liu ◽  
Xing Ai
Keyword(s):  
Residual Stress ◽  
Material Properties ◽  
Element Model ◽  
Clamping Force ◽  
Processing Sequence ◽  
Initial Residual Stress ◽  
Machining Deformation ◽  
Proposed Model ◽  
Key Techniques ◽  
Monolithic Components

When machining aerospace monolithic components, most of materials could be removed, resulting in severe deformation of the parts due to the release and redistribution of the blank’s original residual stress, together with the action of cutting loads and clamping force. A finite element model (FEM) is built for predicting the deformation caused by those factors mentioned above. In this model, some key techniques such as material properties, initial residual stress model, and application of dynamic cutting loads and transformation of boundary condition are discussed in details. The proposed model predicts the machining deformation for multi-frame monolithic components. Particular attention is paid to the influence of the bulkhead processing sequence on part deformation. At last the paper puts forwards optimal bulkhead processing sequence based on minimizing the machining deformation.

Validation of Residual Stresses of Finite Element Simulation of Multi Pass Butt-Welded Plates Using the Contour Method

2011 ◽  
Vol 681 ◽  
pp. 67-72
Author(s):  
Eduardo Rodríguez ◽  
Cristina Martín ◽  
José Luis Cortizo ◽  
Julio Guirao ◽  
José Manuel Sierra
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Finite Element Simulation ◽  
Fe Simulation ◽  
Coordinate Measuring Machine ◽  
Contour Method ◽  
Element Simulation ◽  
Measuring Machine ◽  
Number Of Passes ◽  
Good Agreement

In this paper a comparison between the results obtained using multi pass welding finite element (FE) simulation and the contour method was made to evaluate the accuracy in residual stresses simulated for plates with different thicknesses. The contour method has been used to measure the residual stresses in multi pass butt-welded plates. Two 316 austenitic stainless steel multi pass Metal Inert Gas (MIG) butt-welded plates of 10 mm thickness were cut using wire Electric Discharge Machining (EDM). The measurements of the cross-section were made with a coordinate measuring machine (CMM) and the points obtained were used to calculate the residual stresses by mean of static analysis of finite elements. A multi pass welding FE simulation of the two plates was made to obtain the residual stresses after time cooling. The simulated results are generally in good agreement with the experimental measurements. Other plates of 25 mm thickness and the same material were multi pass MIG butt-welded to evaluate the behavior with different thicknesses. In this case the number of passes was 11. The same method was applied to obtain the residual stresses. A comparison between different thicknesses was made. The residual stresses validation will allow the finite element simulation to be used for the later simulation of residual stresses relaxation.

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.

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.

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.

A Finite Element Model of Orthogonal Metal Cutting

1985 ◽  
Vol 107 (4) ◽  
pp. 349-354 ◽  
Author(s):  
J. S. Strenkowski ◽  
J. T. Carroll
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Element Model ◽  
Effective Plastic Strain ◽  
Orthogonal Metal Cutting ◽  
Chip Separation ◽  
Chip Geometry

A finite element model of orthogonal metal cutting is described. The paper introduces a new chip separation criterion based on the effective plastic strain in the workpiece. Several cutting parameters that are often neglected in simplified metal-cutting models are included, such as elastic-plastic material properties of both the workpiece and tool, friction along the tool rake face, and geometry of the cutting edge and workpiece. The model predicts chip geometry, residual stresses in the workpiece, and tool stresses and forces, without any reliance on empirical metal cutting data. The paper demonstrates that use of a chip separation criterion based on effective plastic strain is essential in predicting chip geometry and residual stresses with the finite element method.

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

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