Modeling, Simulation and Analysis of Weld-Induced Thermal Stresses in a Solid Round-on-Flat Plate Fillet Weld

2017 ◽  
Author(s):  
Suhash Ghosh ◽  
Chittaranjan Sahay ◽  
Haider Al-Mamoury
Keyword(s):  
Thermal Stresses ◽  
Rapid Heating ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Fe Model ◽  
Modeling Simulation ◽  
Heating And Cooling ◽  
Mechanical Formulation ◽  
Stress Components

In this paper, development of a finite element model for simulating welding-induced thermal stresses is discussed. This nonlinear FE model employs sequentially coupled three-dimensional thermo-mechanical formulation. A solid three dimensional 20 node brick elements have been used in ABAQUS, a linearly elastic and linearly plastic approach is implemented in the analysis. The effects of key process parameters, viz., power, size and speed of welding has been discussed. Further, the need for interfacial elements, instead of solid mesh elements to simulate molten weld solidification, has been investigated. Model validation with published literature has been employed to determine the appropriate properties for the interfacial element (shear and normal). Due to the nature of the welding process, heat generation from moving heat source, rapid heating and cooling gives rise to high stresses in the weld. These stresses have been observed to be greatly influenced by the process variables as well the properties of the selected interfacial element. Position, orientation and magnitude of the highest residual stress components are discussed.

Modeling and Analysis of Weld Geometries, Size and Gap on Weld-Induced Thermal Stresses in a Solid Round-on-Flat Plate Fillet Weld

2017 ◽  
Author(s):  
Suhash Ghosh ◽  
Chittaranjan Sahay ◽  
Haider Al-Mamoury
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thermal Stresses ◽  
Rapid Heating ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Fe Model ◽  
Fillet Weld ◽  
Modeling And Analysis

In this paper a finite element model is presented which describes the effects of fillet weld geometry on the thermal stresses. In a separate research, development of a finite element model for simulating welding-induced thermal stresses is discussed. This nonlinear FE model employs fully coupled three-dimensional thermo-mechanical formulation, including interfacial element to simulate the weaker solidified molten weld pool. Due to the nature of the welding process, heat generation from moving heat source, rapid heating and cooling gives rise to high stresses in the weld. This research investigates the effect of weld shape & size, weld gap, (l/d ratio) depth of weld to size ratio on the generated thermal stresses. The size of the round and flat stocks has been varied to investigate their effects of the stresses as well as to determine the thick-to-thin geometry limits based on acceptable design limits of thermal stresses.

Evaluation of Thermal Distribution in Friction Stir Welding on Dissimilar Materials (Cu-Al) Using Infrared Thermography and Numerical Simulation

2016 ◽  
Vol 1138 ◽  
pp. 113-118
Author(s):  
Monica Iordache ◽  
Eduard Nitu ◽  
Claudiu Badulescu ◽  
Doina Iacomi ◽  
Lia Nicoleta Boţilă ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Infrared Thermography ◽  
Three Dimensional ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Element Model ◽  
Fe Model ◽  
Friction Stir ◽  
Solid State Joining ◽  
Joining Process

Friction Stir Welding (FSW) is a solid state joining process realized by the interaction between a non-consumable welding tool that rotates on the contact surfaces of the combined parts. Welding dissimilar materials aluminum and copper by FSW are of great interest because Al and Cu are two most common engineering materials widely used in many industries. This paper presents an investigation concerning the influence of the rotation of the tool on temperatures during the welding process. Also, the welding of copper and aluminum materials by FSW process was simulated using a finite element model. Three-dimensional FE model has been developed in ABAQUS/Explicit using the Coupled Eulerian Lagrangian method, the Johnson–Cook material law and the Coulomb’s Law of friction and was validated by infrared thermography method and thermocouple measurement.

Management of Complex Loading Histories for Use in Probabilistic Creep-Fatigue Damage Assessments

2018 ◽  
Author(s):  
N. A. Zentuti ◽  
J. D. Booker ◽  
R. A. W. Bradford ◽  
C. E. Truman
Keyword(s):  
Fatigue Damage ◽  
Input Parameter ◽  
Three Dimensional ◽  
Complex Loading ◽  
Fe Model ◽  
Plant Component ◽  
Fatigue Lifetime ◽  
Wide Range ◽  
Stress Components ◽  
Creep Fatigue

An approach is outlined for the treatment of stresses in complex three-dimensional components for the purpose of conducting probabilistic creep-fatigue lifetime assessments. For conventional deterministic assessments, the stress state in a plant component is found using thermal and mechanical (elastic) finite element (FE) models. Key inputs are typically steam temperatures and pressures, with the three principal stress components (PSCs) at the assessment location(s) being the outputs. This paper presents an approach which was developed based on application experience with a tube-plate ligament (TPL) component, for which historical data was available. Though both transient as well as steady-state conditions can have large contributions towards the creep-fatigue damage, this work is mainly concerned with the latter. In a probabilistic assessment, the aim of this approach is to replace time intensive FE runs with a predictive model to approximate stresses at various assessment locations. This is achieved by firstly modelling a wide range of typical loading conditions using FE models to obtain the desire stresses. Based on the results from these FE runs, a probability map is produced and input(s)-output(s) functions are fitted (either using a Response Surface Method or Linear Regression). These models are thereafter used to predict stresses as functions of the input parameter(s) directly. This mitigates running an FE model for every probabilistic trial (of which there typically may be more than 104), an approach which would be computationally prohibitive.

scholarly journals Condensation method in practical modal analysis of hull vibration with application of 3D FE model

2019 ◽  
pp. 162-169
Author(s):  
Valeriy Sutyrin
Keyword(s):  
Modal Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Fe Model ◽  
Structural Elements ◽  
Natural Vibrations ◽  
Condensation Method ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Analytical Approaches

This paper gives modal analysis results for mid-body of a refrigerator carrier ship by means of combined three-dimensional finite-element model with 1.5 million DOF. The study estimates the error of modal analysis for the ship structure if its boundary conditions are specified in advance, i.e. approximately, as well as analyses the gain in time offered by structuring the analytical model as per reduction (condensation) method. Analytical approaches thus transformed can be successfully applied in filtering lower frequencies and modes of natural vibrations for structural elements and joints of hull in the direct vicinity of exciting force application points.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

scholarly journals A robust 3D finite element model for concrete columns confined by FRCM system

2019 ◽  
Vol 281 ◽  
pp. 01006 ◽  
Author(s):  
Majid M.A. Kadhim ◽  
Mohammed J Altaee ◽  
Ali Hadi Adheem ◽  
Akram R. Jawdhari
Keyword(s):  
Finite Element ◽  
Cement Mortar ◽  
Three Dimensional ◽  
Concrete Columns ◽  
Element Model ◽  
Fe Model ◽  
3D Finite Element ◽  
Composite Failure ◽  
Global Buckling ◽  
Fibre Reinforced Polymer

Fibre reinforced cementitious matric (FRCM) is a recent application of fibre reinforced polymer (FRP) reinforcement, developed to overcome several limitations associated with the use of organic adhesive [e.g. epoxies] in FRPs. It consists of two dimensional FRP mesh saturated with a cement mortar, which is inorganic in nature and compatible with concrete and masonry substrates. In this study, a robust three-dimensional (3D) finite element (FE) model has been developed to study the behaviour of slender reinforced concrete columns confined by FRCM jackets, and loaded concentrically and eccentrically. The model accounts for material nonlinearities in column core and cement mortar, composite failure of FRP mesh, and global buckling. The model response was validated against several laboratory tests from literature, comparing the ultimate load, load-lateral deflection and failure mode. Maximum divergence between numerical and experimental results was 12%. Following the validation, the model will be used later in a comprehensive parametric analysis to gain a profound knowledge of the strengthening system, and examine the effects of several factors expected to influence the behaviour of confined member.

A finite element model to study the effect of porosity location on the elastic modulus of a cantilever beam

2019 ◽  
Vol 43 (4) ◽  
pp. 443-453
Author(s):  
Stephen M. Handrigan ◽  
Sam Nakhla
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Fe Model ◽  
Three Dimensional Finite Element

An investigation to determine the effect of porosity concentration and location on elastic modulus is performed. Due to advancements in testing methods, the manufacturing and testing of microbeams to obtain mechanical response is possible through the use of focused ion beam technology. Meanwhile, rigorous analysis is required to enable accurate extraction of the elastic modulus from test data. First, a one-dimensional investigation with beam theory, Euler–Bernoulli and Timoshenko, was performed to estimate the modulus based on load-deflection curve. Second, a three-dimensional finite element (FE) model in Abaqus was developed to identify the effect of porosity concentration. Furthermore, the current work provided an accurate procedure to enable accurate extraction of the elastic modulus from load-deflection data. The use of macromodels such as beam theory and three-dimensional FE model enabled enhanced understanding of the effect of porosity on modulus.

A STRUCTURAL ANALYSIS AND TOPOLOGY OPTIMIZATION ON CYLINDER BLOCK OF HEAVY DUTY DIESEL ENGIN

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2676-2681 ◽  
Author(s):  
HYUN-SEUNG LEE ◽  
YOUNG-SHIN LEE ◽  
JAE-HOON KIM ◽  
JOON-TAK JUN ◽  
JAE-OK LEE ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Structural Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Cylinder Block ◽  
Fe Model ◽  
Heavy Duty ◽  
Compacted Graphite ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

The heavy duty diesel engine must have a large output for maintaining excellent mobility. In this study, a three-dimensional finite element model of a heavy-duty diesel engine was developed to conduct the stress analysis by using property of CGI. The compacted graphite iron (CGI) is a material currently under study for the engine demanded for high torque, durability, stiffness, and fatigue. The FE model of the heavy duty diesel engine section consisting of four half cylinders was selected. The heavy duty diesel engine section includes a cylinder block, a cylinder head, a gasket, a liner, a bearing cap, bearing and bolts. The loading conditions of engine are pre-fit load, assembly load, and gas load. A structural analysis on the result was performed in order to optimize on the cylinder block of the diesel engine.

scholarly journals A Three-Dimensional Finite-Element Model of a Human Dry Skull for Bone-Conduction Hearing

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Namkeun Kim ◽  
You Chang ◽  
Stefan Stenfelt
Keyword(s):  
Finite Element ◽  
Bone Conduction ◽  
Three Dimensional ◽  
Human Head ◽  
Element Model ◽  
Fe Model ◽  
Lateral Direction ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

A three-dimensional finite-element (FE) model of a human dry skull was devised for simulation of human bone-conduction (BC) hearing. Although a dry skull is a simplification of the real complex human skull, such model is valuable for understanding basic BC hearing processes. For validation of the model, the mechanical point impedance of the skull as well as the acceleration of the ipsilateral and contralateral cochlear bone was computed and compared to experimental results. Simulation results showed reasonable consistency between the mechanical point impedance and the experimental measurements when Young’s modulus for skull and polyurethane was set to be 7.3 GPa and 1 MPa with 0.01 and 0.1 loss factors at 1 kHz, respectively. Moreover, the acceleration in the medial-lateral direction showed the best correspondence with the published experimental data, whereas the acceleration in the inferior-superior direction showed the largest discrepancy. However, the results were reasonable considering that different geometries were used for the 3D FE skull and the skull used in the published experimental study. The dry skull model is a first step for understanding BC hearing mechanism in a human head and simulation results can be used to predict vibration pattern of the bone surrounding the middle and inner ear during BC stimulation.

scholarly journals Moisture Induced Deformations in Glulam Members - Experiments and 3-D Finite Element Model

2017 ◽  
Vol 36 (2) ◽  
pp. 35-45
Author(s):  
Henry M. Kiwelu
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Solid Wood ◽  
Average Moisture Content ◽  
Fe Model ◽  
Fe Modelling ◽  
Average Value ◽  
Hybrid Buildings ◽  
External Shape

Experiments were performed on scaled glue laminated bending specimens to observetime dependent development of deformations during drying and wetting. Measurementsdetermined changes in the average moisture content and external shape and dimensionsbetween when specimens were placed into constant or variable climates. Alterations inthe external shape and dimensions reflected changes in the average value anddistribution of moisture and mechanosorptive creep in the glulam. The results are beingused to develop a sequentially-coupled three-dimensional hygrothermal Finite Element(FE) model for predicting temporally varying internal strains and external deformationsof drying or wetting solid wood structural components. The model implies temporallyvarying, and eventual steady, state internal stress distributions in members based onelastic and creep compliances that represent wood within glulam as a continuousorthotropic homogenised material. Thus, predictions are consistent with smearedengineering stress analysis methods rather than being a physically correct analogue ofhow solid wood behaves. This paper discusses limitations of and intended improvementsto the FE modelling. Complementary investigations are underway to address otheraspects of the hygrothermal behaviour of structural members of wood and othermaterials (e.g. reinforced concrete) embedded within superstructure frameworks ofmulti-storey hybrid buildings.

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