WeldingMd Irfan Alam (11310R003)

EXPLOSION Harshit Choube (113100063)  Paul Dason Samuel(113109006)

Contents24

Welding Parameters3 SimulationPressure & Stress Profile

Principle

576

2

ConclusionVelocity Profile

Introduction1

Introduction

Explosion welding is a solid-state process that produces a high velocity interaction of dissimilar metals by a controlled detonation.Oxides found on material surfaces must be removed by effacement or dispersion.Surface atoms of two joining metals must come into intimate contact to achieve metallic bond

Explosion bonding process.

Principle

Prime component is placed either parallel or at an angle to the base.Explosive is distributed over top surface of prime component.Upon detonation, prime component collides with base component to complete welding.

Detonation

Primecomponent

Basecomponent

Weld

Action between componentsduring explosion welding.

Jet

Process Variables and ControlVariables:

Collision Velocity Collision Angle Prime Component VelocityThese are Controlled By: Component Mass Explosive Charge Initial Geometry - Standoff Distance or Angle

P = v𝛒 2

𝛒 = Plate density

V = charge velocity

Explosive Pressure

Experiment

Test No.

Flyer Plate thickness

(mm)

Measured Flyer Velocity

(m/s)

Stand-off(mm)

Explosive Thickness

(mm)

Detonator velocity Vd

(m/s)Results

1 3 280 3 107 2050 Wavy

2 3 380 6 107 2050 Shallow waves

3 6 210 3 135 2250 Mostly un-bonded

4 6 250 6 135 2250 Partial bonding

5 12 245 6 235 2400 Partial bonding

6 12 300 12 235 2400 Wavy interface

Experiment Results with Stainless steel as a flyer plate material in parallel condition with ANFO explosive

Simulation

Test No.

Measured Flyer Velocity

(m/s)

PredictedFlyer Velocity

(m/s)

Predicted Collision Velocity

(m/s)

PredictedmaximumPressure

(GPa)

Predictedmaximum

shearstress (GPa)

1 300 294 2250 5.28617 0.264

2 330 324 2250 5.81482 0.290

3 245 337 2400 4.26927 0.213

4 300 310 2400 5.55757 0.277

5 340 358 2400 6.39333 0.319

6 400 394 2400 7.01322 0.350

Results from ABAQUS model:

Velocity Profile

Vertical velocity of flyer and base plate

flyer plate eventually attained a terminal velocity for sufficiently large stand-off distance

vertical velocity profile for the flyer obtained from the ABAQUS analyses are shown in red in Fig.

velocity increases from zero to its highest at the collision point and then the velocity reaches zero

Pressure Distribution

Pressure profiles of flyer and base plates at one instant in timeContact pressure (normal to surface)

Contact pressures are about 107 PaHighest pressure is at collision of the order of 109 Pa

Pressure Contour

Inclined arrangements – pressure contour

Parallel arrangements – pressure contour

Pressure Contour

Pressure gradient profiles of flyer plate at 0.3 m from the edges of the plates

Pressure gradient is negative ahead of a stagnation point and positive behind.Decreasing from zero at infinity to a minimum value and reaching again at x = 0; to rise to a maximum positive value behind the collision point.

Stress Profile

Normal stress profiles of flyer and base plates

Shear stress profiles of flyer and base plates – parallel geometry

Stress Contour

Normal stress contours – Parallel arrangements

Normal stress contours – Inclined arrangements

Conclusion

Relationships between operational conditions and physical parameters, such as local stresses, strains and particle velocities which determine the success or failure of the weld were identified.Bonding is dependent on the level of induced plastic strain in the two materials exceeding a threshold level. In the case of simulations of the bonded plates the shear stresses were of opposite sign but had the same sign for non-welded plates.

References:

1. S.A.A. Akbari Mousavi, S.T.S. Al-Hassani , “Finite element simulation of explosively-driven plate impact with application to explosive welding” Materials and Design 29 (2008) 1–19.2. A.A. Akbari Mousavi, S.J. Burley, S.T.S. Al-Hassani, “Simulation of explosive welding using the Williamsburg equation of state to model low detonation velocity explosives”, International Journal of Impact Engineering 31 (2005) 719–734.3. Yuxin Wang, H.G. Beom , Ming Sun, Song Lin, “Numerical simulation of explosive welding using the material point method”, International Journal of Impact Engineering 38 (2011) 51e60.4. A.A. Akbari Mousavia, S.T.S. Al-Hassani, “Numerical and experimental studies of the mechanism of the wavy interface formations in explosive/impact welding”, Journal of the Mechanics and Physics of Solids 53 (2005) 2501–2528

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