How short-range adhesion slows down crack closure and contact formation.

Area of Science:

• Materials Science
• Physics
• Tribology

Background:

• Adhesive contact rupture in viscoelastic materials is well-researched.
• Contact formation in these systems remains less understood.

Purpose of the Study:

• To investigate the contact formation process between power law indenters and viscoelastic foundations.
• To analyze the relationship between macroscopic relaxation time and adhesion range.

Main Methods:

• Computational simulations were employed.
• The study modeled contact formation using various power law indenters.
• An adhesive, viscoelastic foundation was utilized.

Main Results:

• Macroscopic relaxation time (τ) was found to scale with the inverse of the adhesion range (ρ) to the power of 1.8 (τ ∝ 1/ρ^1.8).
• The Tabor parameter was observed to prolong contact formation.
• Increased energy dissipation from short-range adhesion was identified as a key factor.

Conclusions:

• The study provides insights into the mechanics of adhesive contact formation.
• The findings contribute to understanding the role of viscoelasticity and adhesion in contact dynamics.
• The relationship between relaxation time, adhesion range, and dissipation offers a new perspective on contact phenomena.