Multi-scale characterization of viscoelastic properties in structural adhesives using PZT resonance and non-contact impulse validation
Year: 2025
Type: article
Abstract: Technical datasheets for structural adhesives, such as epoxies, methacrylates, and polyurethanes, typically report static elastic moduli but rarely include Poisson's ratios or damping characteristics, which are essential for applications involving dynamic or vibratory loading. This study presents a non-destructive methodology for determining the dynamic Young's modulus, Poisson's ratio, and damping properties using resonant ultrasonic vibration (RUV) combined with inverse finite element analysis. Experimental data from six structural adhesives revealed a quadratic relationship between the damping coefficient and the ratio of dynamic to static Young's moduli. This behavior was found to be consistent with a viscoelastic representation based on the Kelvin–Voigt mechanical model and scaling principles from the Doi-Edwards theory for entangled polymer networks. The resulting model expresses the storage modulus as a quadratic function of the damping ratio and is validated in a high-frequency regime above , where strain rates are significantly elevated. To complement the RUV tests, transient mechanical impulse excitation and non-contact laser vibrometer velocity measurements were conducted on larger specimens to capture lower-frequency modes. This multi-scale characterization strategy enabled validation of resonance frequencies and extended the applicability of the model. Among the adhesives tested, Sikadur 30 exhibited the highest stiffness, whereas 3M 2216 showed the lowest. 3M 2216 also demonstrated the greatest damping capacity, while Sicomin presented the lowest stiffness. Araldite and 3M 2216 displayed the highest Poisson's ratios, while the other adhesives (Loctite, SAF 30, Sicomin, and Sikadur 30) showed comparably low values. In terms of modulus ratio, SAF 30 recorded the highest value, whereas Sicomin exhibited the lowest. Additionally, glass transition temperature ( ) measurements clarified that the adhesives with the lowest stiffness corresponded to those with the lowest , linking reduced rigidity to lower transition temperatures. The proposed model, fitted to the modulus-to-damping ratio data, offers a framework for selecting structural adhesives in applications requiring both mechanical strength and vibrational energy dissipation.
Source: Results in Engineering
Authors: Serges Kikwani, Erick Ogam, Fréderic Lebon
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
OpenAlex ID: W4415973954