Numerical examples computations by Mathieu Schryve

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Numerical examples (computations by Mathieu
Schryve)
Dynamic contact between a stiff sphere and a
viscoelastic cylindrical block treated with
axisymmetric conditions
Sphere (elastic behaviour)
Block (viscoelastic behaviour)
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An indentation example
Effect of the adhesion parameters
? 1
750 nodes 30 nodes of
contact
3 cases of adhesion law
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Results in case 1
weak bonds, weak energy

• Definitions
• adhesion radius zone of attraction and
  compressive forces ( )
• contact radius zone of compressive forces (
  )

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Results in case 2
strong bonds, weak energy
An initial fold due to adhesion
Still having loss of contact
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Results in case 3
strong bonds, strong energy
An initial fold due to adhesion
Increase of the contact radius
No loss of contact
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Approximation of the purely elastic problem
A rebound example
Adhesion parameters
w 104 J.m-2
CN 103 N.m-3
b 0.1 Ns.m-1
Viscosity parameter values ?
case 1 ? 1 case 2 ? 2.10-2
case 3 ? 10-3
Position of the point where the value of ß is
presented
750 nodes 30 nodes of
contact
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case 1 ? 1
The viscoelasticity is  maximal 
Adhesion radius
Value of ß
No rebounds
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case 2 ? 2.10-2
The viscoelasticity is  moderate 
Adhesion radius
time (s)
Value of ß
A small rebound appears
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case 3 ? 10-3
The elastic case is approximated
Adhesion radius
Value of ß
Rebounds are present