Session: 03-02-03: Applied Innovations in Solid-State Processes and Surface Engineering: Technologies for Advanced and Sustainable Manufacturing III

Paper Number: 164173

Investigating Pressure-Dependent Friction Mechanisms of Additively Manufactured Surface-Textured Composites on Icy Surfaces 

The coefficient of friction (COF) is the primary factor in determining a material's resistance to slippery surfaces, particularly on ice. This resistance is influenced by many factors, with contact pressure being the most important. Recently, surface-textured composites have been introduced to enhance friction in icy conditions. These composites consist of microfibers that protrude from the surface, allowing them to penetrate the ice substrate beneath and provide traction through mechanical interlocking. Contact pressure determines whether the protruding fibers can penetrate the ice to generate traction, yet this aspect has not been thoroughly explored in the literature. As such, this study has two primary objectives: first, to investigate how the ice friction properties of surface-textured composites vary with pressure, and second, to determine whether a relationship exists between the material properties of these composites and the pressure-dependence of their ice friction performance. Building on our previous work, we applied additive manufacturing techniques to create two bio-inspired surface-textured composites. One composite, designed to mimic the frictional properties of polar bear paws, incorporated microfibers, while the other, inspired by both polar bear and frog feet, combined 2D materials with microfibers to enhance friction. The static frictional behavior of these composites was investigated under nominal pressures of 112 kPa, 234 kPa, and 370 kPa on icy surfaces maintained between -5°C and -7°C, using a custom-built setup. Additionally, the material properties of both composite compositions were measured in tension, and their bending properties were evaluated to assess the interlayer bonding between printed layers, both experimentally and computationally. The pressure dependency results demonstrate that, at lower ice temperatures, the COF increases with increasing pressure. This trend is primarily attributed to the hardening of the ice and the composite's ability to penetrate the rigid surface, enhancing mechanical interlocking through microfibers. The mechanical properties measurements showed a modulus of elasticity ranging from 380 to 430 MPa, yield strength ranging from 32 to 38 MPa, and ultimate tensile strength (UTS) ranging from 33 to 40 MPa. The correlation between the mechanical properties measured under tension and the pressure-dependent behavior of these composites revealed that those with a higher modulus of elasticity, yield strength, and UTS exhibited a higher pressure-dependency for ice friction. The bending measurements showed a flexural modulus ranging from 300 to 340 MPa and a flexural strength between 15 and 18 MPa, with no delamination observed after the test. Both experimental and simulation results confirmed strong bonding between the printing layers, with no layer delamination occurring under nominal applied pressures. This study is the first to evaluate the impact of pressure on the ice friction performance of surface-textured composites, a novel material recently introduced for footwear outsoles on icy surfaces. These findings enhance the understanding of friction mechanisms in these textured composites and provide valuable insights for optimizing their performance in cold, icy environments.

Presenting Author: Sabrina Islam George Mason University

Presenting Author Biography: I am a third-year PhD student at George Mason University and am currently pursuing a secondary master's in applied engineering physics at George Mason University. I completed my BSc at Khulna University of Engineering and Technology in Bangladesh. I am a mechanical engineer with 2.5+ years of experience in advanced material and manufacturing labs and 3+ years of experience in different corporate fields, focusing on composite material, FDM and SLA 3D printing, polymer extrusion, and design. I focus on developing slip-resistant footwear using composite shoe sole materials. My research involves the mechanical characterization of FFF-printed composite materials for outsoles.

Authors:

Sabrina Islam George Mason University
Z. Shaghayegh Bagheri George Mason University