Residual stress evolution during ice accretion from a single water droplet

Ice accretion on solid surfaces at low temperatures causes serious problems in numerous engineering applications, such as aircraft, wind turbines, and power lines. To develop effective anti-icing and de-icing technologies, understanding the mechanism of residual stress evolution within the ice film during the accretion process is essential. In this study, experiments were conducted to clarify the residual stress evolution during the solidification of a single water droplet dropped onto a low-temperature stainless steel substrate. In-situ observations of the droplet impact, spreading, and solidification were performed, varying the substrate temperature as a key parameter. Simultaneously, strain was measured on the substrate's backside using a strain gauge, showing that tensile strain develops on the substrate as the droplet solidifies. Furthermore, the residual strain increased with the decreasing substrate temperature. Cracking occurred immediately at lower substrate temperatures, whereas higher temperatures required additional cooling for cracking. Numerical analysis reproduced these experimental observations, quantifying the stress evolution within the ice film. Temperature-dependent material properties were incorporated in the analysis, as well as a creep constitutive equation based on stress relaxation tests, thereby capturing the time-dependent residual strain on the substrate and elucidating the distribution and evolution of tensile residual stress within the ice film. Ultimately, tensile stress developed during solidification and increased with cooling, reaching approximately 7–8 MPa at the time of cracking. These findings provide a fundamental understanding of the thermo-mechanical processes during ice accretion, crucial for developing robust anti-icing and de-icing strategies. • Revealed tensile residual strain develops on substrate during droplet icing. • Quantified residual stress evolution and cracking in ice film via FEA. • Incorporated creep to explain temperature-dependent cracking behavior. • Established fundamental thermo-mechanical understanding of ice accretion.