International Journal of Mechanical Engineering and Technology (IJMET)
Volume 10, Issue 01, January 2019, pp. 867–873, Article ID: IJMET_10_01_090
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=10&IType=01
ISSN Print: 0976-6340 and ISSN Online: 0976-6359
© IAEME Publication
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VALEDICTION OF RESIDUAL STRESS
MEASURED USING HOLE-DRILLING METHOD
WITH 3D SIMULATION THAT DEVELOPED
DURING TIG WELDING OF AISI 304 SS PLATES
Ramachandran Natarajan*
Assistant Professor, Department of Mechanical Engineering, Sri Krishna College of
Engineering and Technology, Coimbatore, Tamil Nadu, India.
Senthilmurugan Arumugam
Assistant Professor, Department of Automobile Engineering, RVS Technical Campus,
Coimbatore, Tamil Nadu, India.
Arvind Mohanasundaram
UG Student, Department of Mechanical Engineering, Sri Krishna College of Engineering and
Technology, Coimbatore, Tamil Nadu, India.
Divaakar Dharumarajan
UG Student, Department of Mechanical Engineering, Sri Krishna College of Engineering and
Technology, Coimbatore, Tamil Nadu, India.
Dineskumar Palaniswamy
UG Student, Department of Mechanical Engineering, Sri Krishna College of Engineering and
Technology, Coimbatore, Tamil Nadu, India.
Dinesh Gunasekaran
UG Student, Department of Mechanical Engineering, Sri Krishna College of Engineering and
Technology, Coimbatore, Tamil Nadu, India.
*corresponding author
ABSTRACT
Welding is aneffective permanent metal joining processes among all other processes
in manufacturing. In welding, a thermal cycle is applied to the weldment. Where welding
temperature differs across the material which results in irreversible elastic-plastic
deformation and itinduces the residual stresses in and around the welded and heat
affected zone (HAZ). Presence of residual stresses may be beneficial or harmful based on
the magnitude available along the thickness of the weldment. Here hole-drilling method
is adapted to measure residual stresses on the fusion zone of weldment as it suits well
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867
editor@iaeme.com
Ramachandran Natarajan, Senthilmurugan Arumugam, Arvind Mohanasundaram, Divaakar
Dharumarajan, Dineskumar Palaniswamy and Dinesh Gunasekaran
with the study of uniform residual stress in a localized area. From the experimental results
of hole-drilling method obtained from sophisticated laboratory setup under high
precision is set for further investigation. Using finite element based commercially
available software coupled thermo-mechanical 3D finite element model was developed
by with adefined geometry of the butt welded joint with prerequisite welding parametric
conditions adopted during fabrication process. FEM analysis was performed to
investigate themagnitude of residual stresses along its thickness in manual GTAW welded
joint of AISI 304 stainless steel plate. Variation of residual stress in the vicinityof top
surface of welded zone also studied.
Keywords: weldment, thermo-mechanical 3D finite element
Cite this Article: Ramachandran Natarajan, Senthilmurugan Arumugam, Arvind
Mohanasundaram, Divaakar Dharumarajan, Dineskumar Palaniswamy and Dinesh
Gunasekaran, Valediction of Residual Stress Measured Using Hole-Drilling Method with
3d Simulation that Developed During Tig Welding Of Aisi 304 Ss Plates, International
Journal of Mechanical Engineering and Technology, 10(01), 2019, pp.867–873
http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=10&Type=01
1. INTRODUCTION
AISI 304 stainless has greater application over other stainless steel because of its restored
properties like better corrosion resistance, ductility, forming and spinning ability. Some of the
important application is manufacturing chemical equipment, flatware utensils, coal hopper,
kitchen sinks, marine equipment etc. Residual stresses in the welded material are also considered
to have a serious effect on the main functions of the material. Residual stress is defined as the
“locked-in” stresses inside the structure without the application of any external loads. It is
supposed to be self-balancing within the material based on the direction and magnitude of the
stresses. Increase in fatigue strength of the component can be achieved with the beneficial effect
of compressive stresses and reduce stress corrosion cracking and brittle fracture. In large steel
fabrication industries such as ship building, sub-marine structures, aerospace industry and highspeed train guide ways and pressure vessels and piping in chemical and petrochemical industries
the problem of residual stresses and overall distortion subjected to be a serious issue affecting the
functional characteristics of the component. In some cases welded joint become weak. This is
due to the shortcomings of welding technology and mismatch of the mechanical properties at the
joints. For this vast application of welding joints in the industries, analysis of the residual stresses
in a weldment is a vital task in mechanical engineering design of the component. Welding can
cause highly localized tensile residual stresses that often approach the yield stress of the metal,
yet it is not completely discussed how various parameters of the welding process influence their
distributions [1]. Because of the inherent complexities of the welding process, many factors both
process related and geometry dependent, affect the resultant residual stresses.
2. METHODOLOGY
2.1. FABRICATION
It involves with two finite plates of AISI 304 SS joint with 100 mm length, 6 mm thick and 60
mm wide each, angle of weld-groove is 60° between the plates by GTAW permanent joining
process as shown in the figure 2.1. Where welding parameters taken in this study are travel speed
100mm/min, arc voltage 9 volts, arc current 100amp 10 lt/hr flow rate of argon shielding gas and
arc efficiency 90% for TIG welding.
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Valediction of Residual Stress Measured Using Hole-Drilling Method with 3d Simulation that
Developed During Tig Welding Of Aisi 304 Ss Plates
Figure 2.1
The mechanism that works in a hole-drilling method is when the component containing
residual stresses is cut through, the stresses with force components acting on the cut surface will
relieve and the stresses within the material along the removed surface will redistribute to maintain
interior force equilibrium. Drilling a hole in a localized area can also release the stress which
cause strain on surface of the component. Drilled hole should not alter the properties of
component [2]. With this objective the hole drilling method was carried out in a welded specimen
of flat plate of material AISI 304 SS.
2.2. STRAIN ROSETTE AND INSTALLATION
A strain gauge rosette is an arrangement of two or more closely positioned gauge grids, separately
oriented to measure the normal strains along corresponding directions on the surface of the
specimen. Strain gauge works on the principle that small changes in the gauge length of the
conductor that are caused by a load applied to the test object induce small changes in the
resistance of the conductor. These changes in the gauge resistance are detected by the measuring
instrumentation. Main role to be played by strain gauge is to establish strong thin bond with the
surface of the specimen so that it can obtain even small surface deformations caused by a holedrilling process. There are three standard rosette types are used, and the arrangements of these
types are shown in Figure 2.2 as Type A, Type B and Type C [3]. Marking for hole-drilling
location is indicated at the centre location of the rosettes.
Figure 2.2
For the proposed specimen geometry Type A rosette is considered in order to measure strain
along 0˚, 45˚, 90˚ from the origin. It represents strain along corresponding direction [3]. The
installed strain rosette is shown in Figure 2.3. Strain measurements were carried out at the centre
of weld. It is fixed firmly on the test specimen using Cyanoacrylate based adhesive which are
most widely used. Short lead wires are used to avoid lead wire resistance. These lead wires are
connected to the data acquisition equipment to read and record the experimental data from three
channel of strain rosette.
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Ramachandran Natarajan, Senthilmurugan Arumugam, Arvind Mohanasundaram, Divaakar
Dharumarajan, Dineskumar Palaniswamy and Dinesh Gunasekaran
Figure 2.3
2.3. HOLE-DRILLING METHODOLOGY
The test specimen was clamped and the drilling location was adjusted through the eye piece
position as shown in Figure 2.4. At this locked position the eye piece is replaced with the air
turbine assembly is fixed as shown in Figure 2.3. Now, the drilling operation is carried out at the
centre of the strain gauge rosette using air turbine controlled drilling tool which is capable of
operating the drill at a speed of 40,000 rpm. Micro meter scale is used to control the depth of the
drill provided the screw for adjustment. Hole is drilled at regular interval of depth [4]. The interval
of depth to be drilled is followed with reference to ASTM E837-13a. Locking collar is used to
hold the drill. Strain data is recorded at regular interval of depth from three channel of strain
rosette. It represents strain along corresponding direction. From each channel of the rosette, the
strain was acquired using data acquisition device. The acquired strain is used to calculate the
uniform stress values using the standard calculation method.
Figure 2.4
Graph has been drawn based on the stress values obtained from the experimental
methodology. Its obvious from the graph that stress values increase with increase in depth along
the thickness of the weldment as shown in the figure 2.5.
Figure 2.5
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Valediction of Residual Stress Measured Using Hole-Drilling Method with 3d Simulation that
Developed During Tig Welding Of Aisi 304 Ss Plates
3. ACKNOWLEDGEMENT
Above mentioned Hole-drilling test to measure residual stress is done in Welding Research
Institute, Bharat Heavy Electrical Limited, Tiruchirapalli one of the authorised welding research
institute in India run by Indian Government for Research and Development purposes.
3. SIMULATION OF WELDING PROCESS
In this study of finite element method, the butt-weld joint of two AISI 304 stainless steel plates
is modelled with corresponding geometry and welding parameters using a commercially
available finite element software. Sequential coupled thermo-mechanical analysis is
accomplished considering the birth and death element technique for welding simulation. Solid
tetrahedral 10-node element with three translational degrees of freedom per node is the mesh
content. Mesh control is applied to the weldment area. In plates the top surface of two plates was
allowed to convection of heat. In this paper analysis of stainless steel 304 is performed by Gas
tungsten arc welding (GTAW) in its characteristics of residual stress. Analysing the thermal and
mechanical part separately will simplify the process of welding simulation [6]. First step in the
computation is observing the temperature history during welding and sub sequential cooling after
welding the plates. Observed results of temperature distribution along fusion zone are applied as
a body force to a model to accomplish analysis of residual stress. Required heat input developed
during welding is provided as an heat flux. The Q, amount of heat input is determined by using
empirical relation. Where arc efficiency is denoted by η, arc voltage by U, arc current by I and
travel speed by V. The heat source during each time increment modelled as a moving heat input.
In this analysis welding arc stayed at an element with constant specific volume heat flux, and
then moved to the next element at the end of the load step as the welding is finished. To
accomplish this, TIG welding process of butt joint is simulated in seventeen steps of time
increment with temperature field for time increment of two seconds at each field [7]. Peak
temperature attained among these steps comes out to be 8213.3°C is shown in figure 4.1. By
using this value of heat input first of all by thermal analysis the temperature at various points are
noted and after that the values of residual stresses are calculated by means of stress analysis. This
simulated temperature field is then used in analysis step for calculating the residual stresses [8].
Figure 4.1
4. RESULTS
A three dimensional finite element modelled and the welding is simulated using technique of
element birth and death. The birth of an element takes place when element exposed to heat.
Element birth continues until dissipation of heat reaches ambient temperature through
conduction, convection and radiation. At the end of heat dissipation death of element occurs.
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Ramachandran Natarajan, Senthilmurugan Arumugam, Arvind Mohanasundaram, Divaakar
Dharumarajan, Dineskumar Palaniswamy and Dinesh Gunasekaran
Figure 5.1
Figure 5.1 shows the values of distribution of residual stresses against the distance from weld
centre. Obviously from the plot that heat affected zone experience distortion [9]. It is seen that
the residual stress in the centre of butt welded joint is 1638.5 MPa, result output image is shown
in the figure 5.2.
Figure 5.2
From the study of finite element analysis magnitude of residual stress is high on vicinity of
surface and keeps on decreasing in the direction of its of thickness in its fusion area [10]. Peak
value of residual stress is attained at the centre of welded area.
5. CONCLUSION
Moreover the result of finite element analysis agrees with the values of hole-drilling method. The
finite element method is a suitable method in simulating and analysing residual stresses
stimulated in TIG welding process. The results of finite element analysis of the residual stress
distributions of two butt welded plates along its thickness are studied at the centre of fusion zone.
It helps to conclude that residual stresses are high on the surface of the welded area and heat
affected zone which needs further investigation to prevent component from failure [10]. Also it
can be concluded that the reduced heat input decreases the residual stress distribution in the
material. Further study on residual stress distribution along its thickness is considered.
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Valediction of Residual Stress Measured Using Hole-Drilling Method with 3d Simulation that
Developed During Tig Welding Of Aisi 304 Ss Plates
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