Finite Element Modeling of Hybrid Friction Diffusion Welding of Tube–Tubesheet Joints

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Fadi Al-Badour
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Three Dimensional ◽  
Infrared Camera ◽  
Element Model ◽  
Optical Microscope ◽  
Steel Tube ◽  
Diffusion Welding ◽  
Temperature Dependent ◽  
Mechanical Nature

Abstract A three-dimensional thermo-mechanical finite element model (FEM) was developed and solved to study the feasibility of hybrid friction diffusion bonding (HFDB) technique for welding tube–tubesheet joints using Abaqus/explicit enviroment. Considering the process thermo-mechanical nature, temperature-dependent material properties and Johnson–Cook model were adopted. Two tube configurations were considered in the numerical study; zero projection (flush) and 3 mm projection (extended). For validation purposes, HFDB of tube–tubesheet was experimentally performed on a 19 mm (¾ in.) ASTM 179 cold-drawn carbon steel tube into ASTM A516-70 tubesheet, considering a flush tube configuration. The tool–workpiece temperature was measured using infrared camera, and produced joints were sectioned and examined under optical microscope. A good agreement was found between numericaly estimated temperatures and material deformation with experimentaly measured ones. According to the estimated results, spring back of tube was found to negatively affect the joint integrity. Also, contact stresses during processing phase were found less in the projected tube (extended) as compared to the flush one.

scholarly journals Modeling inflatable fabric with undevelopable surfaces by motion folding method

2019 ◽  
Vol 14 ◽  
pp. 155892501988640
Author(s):  
Xiao-Shun Zhao ◽  
He Jia ◽  
Zhihong Sun ◽  
Li Yu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Study ◽  
Technical Problem ◽  
Three Dimensional ◽  
Element Model ◽  
Model Errors ◽  
Folding Model ◽  
Study Results ◽  
The Stability

At present, most space inflatable structures are composed of flexible inflatable fabrics with complex undevelopable surfaces. It is difficult to establish a multi-dimensional folding model for this type of structure. To solve this key technical problem, the motion folding method is proposed in this study. First, a finite element model with an original three-dimensional surface was flattened with a fluid structure interaction algorithm. Second, the flattened surface was folded based on the prescribed motion of the node groups, and the final folding model was obtained. The fold modeling process of this methodology was consistent with the actual folding processes. Because the mapping relationship between the original finite element model and the final folding model was unchanged, the initial stress was used to modify the model errors during folding process of motion folding method. The folding model of an inflatable aerodynamic decelerator, which could not be established using existing folding methods, was established by using motion folding method. The folding model of the inflatable aerodynamic decelerator showed that the motion folding method could achieve multi-dimensional folding and a high spatial compression rate. The stability and regularity of the inflatable aerodynamic decelerator numerical inflation process and the consistency of the inflated and design shapes indicated the reliability, applicability, and feasibility of the motion folding method. The study results could provide a reference for modeling complex inflatable fabrics and promote the numerical study of inflatable fabrics.

Numerical Study of Welding Sequence on the Residual Stress Field in a Thick-Walled Tee Joint

2011 ◽  
Vol 219-220 ◽  
pp. 1211-1214
Author(s):  
Wei Jiang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Numerical Study ◽  
Three Dimensional ◽  
Element Model ◽  
Residual Stress Field ◽  
Factors Affecting ◽  
Welding Sequence ◽  
Welding Sequences ◽  
Three Dimensional Finite Element

Finite element simulation is an efficient method for studying factors affecting weld-induced residual stress distributions. In this paper, a validated three-dimensional finite element model consisting of sequentially coupled thermal and structural analyses was developed. Three possible symmetrical welding sequences, i.e. one-welder, two-welder and four-welder sequence, which were perceived to generate the least distortion in actual welding circumstances, were proposed and their influences on the residual stress fields in a thick-walled tee joint were investigated. Appropriate conclusions and recommendations regarding welding sequences are presented.

Finite Element Modeling of Hybrid Friction Diffusion Welding of Tube-Tubesheet Joints

2019 ◽  
Author(s):  
Fadi Al-Badour
Keyword(s):  
Finite Element ◽  
Carbon Steel ◽  
Flow Behavior ◽  
Welding Process ◽  
Element Model ◽  
Processing Parameters ◽  
Steel Tube ◽  
Diffusion Welding ◽  
Steel Shell ◽  
Element Analysis

Abstract Hybrid Friction Diffusion Bonding (HFDB) is a solid-state welding process that proved its capability of producing sound tube-tubesheet joints, but with limitations on tube thickness (up to 1mm) and tube-tubesheet materials. In the petrochemical industry, there is a great demand for the use of carbon steel shell and tube heat exchangers. To investigate the feasibility of HFDB techniques in joining thicker tube (i.e 2.1 mm) on tubesheet joint, a three-dimensional thermo-mechanical finite element model (FEM) was developed and solved using ABAQUS (commercial finite element analysis (FEA) software). The model was used to predict the temperature distribution and developed stresses during and after welding. The model considered temperature dependent material properties while Johnson-cook model was used to govern material plastic flow behavior. In this paper,19 mm (¾ in) ASTM 179 cold-drawn carbon steel tube into an ASTM A516 Grade 70 tubesheet joints was simulated. Results are validated based on temperature measurements, which was found in good agreement with experimental results. The developed model can be used to optimize processing parameters (i.e. tool rotational speed, dwell time “holding time”, and forging force.. etc) and study their effect on material flow and developed stresses.

scholarly journals STUDY ON NONLINEAR PAVEMENT RESPONSES OF LOW VOLUME ROADWAYS SUBJECT TO MULTIPLE WHEEL LOADS / NETIESINĖS KELIO DANGOS PRIKLAUSOMYBĖS NUO MAŽO INTENSYVUMO KELIŲ, VEIKIAMŲ DAUGKARTINĖMIS RATŲ APKROVOMIS, TYRIMAS

2011 ◽  
Vol 17 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Minkwan Kim ◽  
Joo Hyoung Lee
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Asphalt Pavement ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Element Analysis ◽  
Nonlinear Stress ◽  
Low Volume ◽  
Stress Dependent

This paper describes numerical analyses on low volume roads (LVRs) using a nonlinear three-dimensional (3D) finite element model (FEM). Various pavement scenarios are analyzed to investigate the effects of pavement layer thicknesses, traffic loads, and material properties on pavement responses, such as surface deflection and subgrade strain. Each scenario incorporates a different combination of wheel/axle configurations and pavement geomaterial properties to analyze the nonlinear behavior of thinly surfaced asphalt pavement. In this numerical study, nonlinear stress-dependent models are employed in the base and subgrade layers to properly characterize pavement geomaterial behavior. Finite element analysis results are then described in terms of the effects of the asphalt pavement thickness, wheel/axle configurations, and geomaterial properties on critical pavement responses. Conclusions are drawn by the comparison of the nonlinear pavement responses in the base and subgrade in association with the effects of multiple wheel/axle load interactions. Santrauka Straipsnyje aprašoma skaitinė mažo intensyvumo kelių analizė, taikant netiesinį—erdvinį baigtinių elementų modelį. Skirtingi dangų paviršiaus variantai analizuojami siekiant ištirti, kokiąįtaką kelio dangos elgsenai, t. y. poslinkiams ir kelio pagrindo deformacijoms, turi dangų sluoksnių storiai, eismo apkrovos ir medžiagų savybės. Kiekvienas kelio dangos variantas turi skirtingas ratų arba ašies ir geometrinių savybių formas, kad būtų galima išanalizuoti netiesinę plonos asfalto dangos paviršiaus elgseną. Šioje skaitinėje analizėje nagrinėjami netiesiniai įtempių modeliai, kurie buvo taikomi pagrindo sluoksniams, siekiant tinkamai apibūdinti geometrinę kelio dangos elgseną. Baigtinių elementų analizės rezultatai toliau nagrinėjami atsižvelgiant į asfalto dangos storį ar ašies formą ir geometrines savybes, priklausomai nuo kritinės kelio dangos būklės. Išvados buvo gautos lyginant netiesines kelių dangos priklausomybes pagrindo sluoksnyje, atsižvelgiant į jų sąveiką su daugkartine ratų apkrova.

Modelling and measuring the thermal behaviour of the molten pool in closed-loop controlled laser-based additive manufacturing

2003 ◽  
Vol 217 (4) ◽  
pp. 441-452 ◽  
Author(s):  
D Hu ◽  
R Kovacevic
Keyword(s):  
Finite Element ◽  
Additive Manufacturing ◽  
Thermal Behaviour ◽  
Molten Pool ◽  
Closed Loop ◽  
Three Dimensional ◽  
Infrared Camera ◽  
Element Model ◽  
Experimental Investigations ◽  
Process Conditions

Laser-based additive manufacturing (LBAM) is a promising manufacturing technology that can be widely applied in solid freeform fabrication (SFF), component recovery and regeneration, and surface modification. The thermal behaviour of the molten pool is one of the critical factors that influences laser deposition indices such as geometrical accuracy, material properties and residual stresses. In this paper, a three-dimensional finite element model is developed using ANSYS to simulate the thermal behaviour of the molten pool in building a single-bead wall via a closed-loop controlled LBAM process in which the laser power is controlled to keep the width of the molten pool constant. The temperature distribution, the geometrical feature of the molten pool and the cooling rate under different process conditions are investigated. To verify the simulation results, the thermal behaviour of the molten pool is measured by a coaxially installed infrared camera in experimental investigations of a closed-loop controlled LBAM process. Results from finite element thermal analysis provide guidance for the process parameter selection in LBAM, and develop a base for further residual stress analysis.

scholarly journals Investigating pipeline–soil interaction under axial–lateral relative movements in sand

2011 ◽  
Vol 48 (11) ◽  
pp. 1683-1695 ◽  
Author(s):  
Nasser Daiyan ◽  
Shawn Kenny ◽  
Ryan Phillips ◽  
Radu Popescu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Study ◽  
Three Dimensional ◽  
Element Model ◽  
Lateral Interaction ◽  
Test Bed ◽  
Dense Sand ◽  
Centrifuge Tests ◽  
Soil Loading

This paper presents results from an experimental and numerical study on the axial–lateral interaction of pipes with dense sand. A series of centrifuge tests were conducted, with a rigid pipeline displaced in the horizontal plane in a cohesionless test bed. The relative pipe–soil interaction included axial, lateral, and oblique loading events. A three-dimensional continuum finite element model was developed using ABAQUS/Standard ( Hibbitt et al. 2005 ) software. The numerical model was calibrated against experimental results. A parametric study was conducted, using the calibrated finite element model to extend the investigations. The ultimate axial and lateral soil loading was found to be dependent on the angle of attack for relative movement between the pipe and soil. Two different failure mechanisms were observed for axial–lateral pipeline–soil interaction. This study confirms and improves on a two-part failure criterion that accounts for axial–lateral coupling during oblique soil loading events on buried pipelines.

Crushing of a Steel Tube Umbilical (STU) Cable During Laying Operation: A Finite Element Method Assessment at the Entry/Exit Regions of Tensioner Shoes

2020 ◽  
Author(s):  
William C. Guttner ◽  
Caio C. P. Santos ◽  
Celso P. Pesce
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Strain Curve ◽  
Element Model ◽  
Steel Tube ◽  
Gas Production ◽  
Three Dimensional Model ◽  
Steel Tubes ◽  
Umbilical Cable

Abstract Umbilical cables are fundamental equipment used in deep and ultra-deep waters oil and gas production systems. The complexity of this kind of structure leads structural analysis to be currently performed with numerical tools. This paper presents a nonlinear three-dimensional finite element model of a typical armored Steel Tube Umbilical Cable (STU) subjected to crushing loads imposed to the umbilical cable during laying operation. The study focuses on the analysis of the stress distribution in the steel tubes at caterpillar shoes, mainly at the entry/exit transition regions. With the use of a commercial software, the finite element model is constructed, considering geometric and materials nonlinearities. Crushing loads are imposed by two rigid plates. Focus is given on the duplex tubes, with the material stress-strain curve modeled from a specific crushing experiment with a single tube and by using a classic Ramberg-Osgood fitting. Firstly, comparisons at mid-length of the three-dimensional model are made with the results from a simpler and planar finite element model. Then, the localized three-dimensional effects are analyzed. The results show a considerable increase of the stress levels in the steel tubes at these transition regions, with the occurrence of stress field redistribution after the onset of plastic deformation.

A Combined Experimental and Numerical Study of the Effect of Surface Roughness on Nanoindentation

2019 ◽  
Vol 11 (07) ◽  
pp. 1950070
Author(s):  
M. Nazemian ◽  
M. Chamani ◽  
M. Baghani
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Finite Element ◽  
Rough Surface ◽  
Numerical Study ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Three Dimensional Finite Element ◽  
Effect Of Surface

Gold and copper thin films are widely used in microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) devices. Nanoindentation has been developed in mechanical characterization of thin films in recent years. Several researchers have examined the effect of surface roughness on nanoindentation results. It is proved that the surface roughness has great importance in nanoindentation of thin films. In this paper, the surface topography of thin films is simulated using the extracted data from the atomic force microscopy (AFM) images. Nanoindentation on a rough surface is simulated using a three-dimensional finite-element model. The results are compared with the results of finite-element analysis on a smooth surface and the experimental results. The results revealed that the surface roughness plays a key role in nanoindentation of thin films, especially at low indentation depths. There was good compatibility between the results of finite-element simulation on the rough surface and those of experiments. It is observed that on rough films, at low indentation depths, the geometry of the location where the nanoindentation is performed is of major importance.

A Finite Element Model for Prediction of the Bending Stress of Umbilicals

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Qingzhen Lu ◽  
Zhixun Yang ◽  
Jun Yan ◽  
Hailong Lu ◽  
Jinlong Chen ◽  
...  
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Three Dimensional ◽  
Friction Stress ◽  
Element Model ◽  
Steel Tube ◽  
Fe Model ◽  
Bending Stress ◽  
3D Finite Element ◽  
Bending Behavior

Umbilical is an important equipment in the subsea production to supply a connection between the floater and the subsea well. Analyzing strength and fatigue behaviors under bending is a key requirement to assure safety. An analytical model is proposed for predicting the bending behavior of a steel tube wounded helically around a frictionless cylinder. A full three-dimensional (3D) finite element (FE) model of an umbilical is developed by considering the frictions and contacts among its components. The numerical results of the bending stress of a steel tube were validated against that of the analytical model. The impacts of friction coefficients on the bending stress, contact pressure, and friction stress have been further investigated by the established FE model.

scholarly journals Analysis of strengthened short deficient rubberized concrete-filled steel tubular columns

2020 ◽  
Vol 15 (55) ◽  
pp. 1-19
Author(s):  
Fady Elshazly ◽  
Suzan Mustafa ◽  
Hesham Fawzy
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Compressive Load ◽  
Element Model ◽  
Crumb Rubber ◽  
Steel Tube ◽  
Fine Aggregate ◽  
Rubberized Concrete ◽  
Structural Behaviour ◽  
Cfst Columns

Concrete-filled steel tubular (CFST) columns are broadly used in many structural systems for their well-known merits. This paper presents a finite element investigation on the structural behaviour of short circular deficient steel tubes filled with rubberized concrete (RuC), under axial compressive load. To accomplish this study, a validation of the proposed three-dimensional nonlinear finite element model; using ANSYS software; was carried out showing good accurateness. The analysis involved two different concrete mixes with 5% and 15% replacement of fine aggregate volume with crumb rubber particles. Columns strength reduction due to horizontal or vertical deficiencies was handled by increasing the thickness of the steel tube or wrapping the columns with two different types of FRP sheets. Five strengthening arrangements were studied using GFRP sheets and CFRP sheets. The results indicated that the ultimate bearing capacity of the RuCFST columns was increased with increasing the steel tube thickness. application of FRP sheets for strengthening the deficient RuCFST columns efficiently managed to retrieve the strength-lost due to either horizontal or vertical deficiency. Moreover, an enhancement in the columns’ ductility was observed especially when using GFRP sheets

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