[Paper Review] A Strong Bond Model for Stress Relaxation of Soft Solid Interfaces

Arun K. Singh, Vinay A. Juvekar|arXiv (Cornell University)|Nov 29, 2014

High-pressure geophysics and materials6 references3 citations

TL;DR

This paper proposes a mathematical model explaining stress relaxation in soft solid interfaces through a transition from weak to strong bonds at a critical time, resulting in non-zero residual stress. The model captures the dynamics of interfacial bonding using parametric analysis and is validated against experimental data, offering a mechanistic explanation for persistent interfacial adhesion in soft materials.

ABSTRACT

In this article, we propose a mathematical model which explains the formation of strong bonds during the relaxation process of a soft solid on a hard surface. As a result, the soft solid relaxes to a non zero residual stress level. The model assumes that formation of strong bonds occurs owing to transition from weak to strong bonds at a critical time. Parametric studies are carried out to understand the effect of different friction parameters related with the model on the relaxation process. The relaxation model is, in turn, validated with experiments and corresponding numerical values are justified.

Motivation & Objective

• To develop a mathematical model explaining the formation of strong interfacial bonds during stress relaxation in soft solids.
• To understand the role of critical time in the transition from weak to strong bonds at soft-solid/hard-surface interfaces.
• To quantify the influence of friction-related parameters on the relaxation process and residual stress levels.
• To validate the model against experimental data and justify numerical parameter values.

Proposed method

• The model introduces a time-dependent bond transition mechanism from weak to strong bonds at a critical time point.
• It employs a parametric framework to analyze the effects of friction parameters on stress relaxation dynamics.
• The relaxation process is modeled using a constitutive approach that accounts for interfacial energy and bond strength evolution.
• The model predicts a non-zero residual stress state due to the formation of strong interfacial bonds.
• Experimental validation is performed by comparing model predictions with measured stress relaxation curves.
• Numerical values for model parameters are justified through correlation with experimental observations.

Experimental results

Research questions

• RQ1 How does the transition from weak to strong interfacial bonds influence the stress relaxation behavior of soft solids?
• RQ2 What is the role of critical time in the formation of strong bonds and the resulting residual stress?
• RQ3 How do friction-related parameters affect the relaxation dynamics and final stress state?
• RQ4 To what extent can the model quantitatively reproduce experimental stress relaxation curves?
• RQ5 What determines the non-zero residual stress level observed in soft solid interfaces after relaxation?

Key findings

• The model successfully explains the emergence of non-zero residual stress in soft solid interfaces due to strong bond formation.
• The transition from weak to strong bonds at a critical time is identified as the key mechanism driving residual stress development.
• Parametric studies show that friction parameters significantly influence the rate and extent of stress relaxation.
• The model's predictions align closely with experimental stress relaxation data, validating its physical consistency.
• Numerical values for model parameters are justified through direct comparison with experimental measurements.
• The model provides a mechanistic explanation for persistent interfacial adhesion in soft materials, resolving long-standing observations of residual stress.