FEM Dynamic Analysis of Continuous Rolling Pass of Seamless Tubes

2011 ◽  
Vol 704-705 ◽  
pp. 1487-1491
Author(s):  
Zhi Long Feng ◽  
Xu Ma ◽  
Jing Yun Ma ◽  
Xiao Yu Zhou ◽  
Hui Qiang Liu ◽  
...  
Keyword(s):  
Cross Section ◽  
High Efficiency ◽  
Rolling Force ◽  
Low Cost ◽  
Deformation Characteristic ◽  
Element Model ◽  
Continuous Rolling ◽  
Pass Design ◽  
Rolling Pass ◽  
Result Show

The development of new products of seamless tubes require the development of corresponding grooves in order to manufacture tubes with high precision, high efficiency at low cost. In this work, a finite element model and dynamic simulation of continuous rolling pass for seamless tubes process has been implemented under the ANSYS/LS-DYNA environment to verify the validity of the pass design. The result show the deformation characteristic of cross-section, the variation regularity of rolling force, strain and stress conform to the reality. The work is effective for developing new grooves and products for seamless tube continuous rolling.

scholarly journals Effects of Thermal Undercooling and Thermal Cycles on the Grain and Microstructure Evolution of TC17 Titanium Alloy Repaired by Wire Arc Additive Manufacturing

2021 ◽  
Author(s):  
Yimin Zhuo ◽  
Chunli Yang ◽  
Chenglei Fan ◽  
Sanbao Lin
Keyword(s):  
Titanium Alloy ◽  
Additive Manufacturing ◽  
High Efficiency ◽  
Low Cost ◽  
Single Layer ◽  
Element Model ◽  
Maximum Effect ◽  
Thermal Cycles ◽  
Layer Deposition ◽  
Wire Arc Additive Manufacturing

Abstract Wire arc additive manufacturing (WAAM) can be used to repair blades or blisk made of titanium alloy with the advantage of high efficiency and low-cost. In this work, the finite element model of repairing the blade based on the arc heat source was established to investigate it. Results showed that the maximum effect of thermal undercooling appears when the peak current transforms to the base current (1Hz or 5Hz), which will promote the grains refinement with the combination of sufficient constitutional supercooling. Compared to the single-layer deposition, the microstructure in the near-heat affected zone (near-HAZ) of multi-layer deposition changes from the metastable β phases to the extremely fine α phases, which was caused by the repeated thermal cycles.

scholarly journals Tabu Genetic Cat Swarm Algorithm Analysis of Optimization Arrangement on Mistuned Blades Based on CUDA

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yi Cai ◽  
Junjie Gu ◽  
Honggang Pan ◽  
Hongyuan Zhang ◽  
Tianyu Zhao
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Synthesis Method ◽  
Solution Space ◽  
Element Model ◽  
Lumped Parameter Model ◽  
Algorithm Analysis ◽  
Engineering Practice ◽  
Disk System ◽  
Bladed Disk

Tabu genetic cat swarm optimization algorithm is proposed for optimization arrangement on mistuned blades. Furthermore, it is improved to be an innovative parallel algorithm based on Compute Unified Device Architecture (CUDA), whose performance is analyzed both in continuous and discrete solution space. The lumped parameter model and finite element model of the bladed-disk system are established for dynamics analysis and optimization verification. The complete mistuned parameter identification method and the improved mixed-interface prestressed substructure modal synthesis method are two other highlights. The results indicate that the algorithm in this paper has the advantages of low cost and high efficiency. The vibration localization and amplitude of the mistuned bladed-disk system are both reduced significantly. The optimization analysis method is proved to be applicable to the mistuned bladed-disk system of the aeroengine in engineering practice.

Pass Design and Finite Element Simulation for Trapezoidal Stainless Steel Sieve Bar

2015 ◽  
Vol 1095 ◽  
pp. 804-807
Author(s):  
Ya Qin Wang ◽  
Rui Liu ◽  
Lu Pan
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Rolling Force ◽  
Metal Flow ◽  
Three Dimensional ◽  
Element Model ◽  
Pass Design ◽  
Pass System ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

According to a company’s trapezoidal stainless steel sieve bar specification, 4-stands pass system and rolling program are proposed. To verify the pass system, 4-stands sieve bar three-dimensional finite element model is established and simulated by ANSYS/LS-DYNA. Parameters, such as metal flow law (metal longitudinal flow, metal lateral flow) and power parameters (stress, strain and rolling force), are obtained, and provide a reference for new product pass design optimization and improvement.

Numerical Study on the Electrohydrodynamic Jet Printing

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xue Yang ◽  
Shuobang Wang ◽  
Zhifu Yin ◽  
Jili Wang ◽  
Wei Hu
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Formation Process ◽  
High Efficiency ◽  
Numerical Study ◽  
Low Cost ◽  
Element Model ◽  
Jet Formation ◽  
Electrohydrodynamic Jet Printing ◽  
Jet Printing

Abstract Electrohydrodynamic (EHD) printing is an alternative method to fabricate high-resolution micro- and nanostructures with high efficiency, low cost, and low pollution. Numerical simulation is an effective approach to systematically investigate the formation process of EHD jet. However, there are a few articles performing this work. In this study, a finite element model was established. The jet formation process and jetting modes were analyzed. The influence of applied voltage and printing distance on the maximum electric field near the nozzle tip was investigated. The effect of flow rate on the jet diameters was studied. Comparison between numerical and experimental results demonstrated that the proposed simulation model had a high potential for EHD jet analysis. According to the optimized printing conditions (printing distance of 200–300 μm, applied voltage of ∼1100 V, and flow rate of 0.1–0.3 ml/h), stable EHD jet can generate and polyvinyl pyrrolidone (PVP) lines with minimum line-width of 0.9 μm can be printed onto the glass slide.

Numerical Simulation Study on the Cold Rolling of Hollow Thread

2010 ◽  
Vol 160-162 ◽  
pp. 849-854 ◽  
Author(s):  
Hui Ping Qi ◽  
Yong Tang Li ◽  
Zhi Qi Liu ◽  
Shi Wen Du
Keyword(s):  
Numerical Simulation ◽  
Cold Rolling ◽  
High Efficiency ◽  
Rolling Force ◽  
Low Cost ◽  
New Technology ◽  
Failure Process ◽  
Tangential Force ◽  
Rolling Process ◽  
Thin Wall

The cold rolling technology of thread was rapidly developed due to its high efficiency, low cost and perfect property of its production. But theoretical researches on the precise forming were very few, especially for the hollow parts. In the rolling process, empirical (trial and error) methods have been a mainly part. This is unfavorable for the development of the new technology. In this paper, numerical simulation of the cold rolling process of hollow thread was studied. The DEFORM soft was used to perform the simulation work. The stress field, strain field and velocity field in the workpiece were obtained. The change curve of the rolling force and the relation curve of tangential force and torque were obtained. The failure process of hollow thread in the rolling process was also simulated. The failure reason of thin wall thread in the rolling process was analyzed according to the change of effective stress in the workpiece. The result is well agreement with theoretical ones. The further research will be done to promote the application of numerical simulation in the cold rolling of hollow thread parts.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

The Numerical Analysis of Contaminant Migration from Sanitary Landfill Sites

1977 ◽  
Vol 12 (1) ◽  
pp. 233-255
Author(s):  
J.F. Sykes ◽  
A.J. Crutcher
Keyword(s):  
Contaminant Transport ◽  
Cross Section ◽  
Element Model ◽  
Sanitary Landfill ◽  
Saturated Porous Media ◽  
Two Dimensional ◽  
Contaminant Migration ◽  
Southern Ontario ◽  
Galerkin Finite Element ◽  
Chloride Concentrations

Abstract A two-dimensional Galerkin finite element model for flow and contaminant transport in variably saturated porous media is used to analyze the transport of chlorides from a sanitary landfill located in Southern Ontario. A representative cross-section is selected for the analysis. Predicted chloride concentrations are presented for the cross section at various horizon years.

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