Shi-Qing Wang - Fellow, Elected 2026

Shi-Qing Wang is internationally recognized for paradigm-shaping contributions to nonlinear polymer rheology and polymer fracture, distinguished by a sustained emphasis on conceptual pictures, physical mechanisms, mechanical stability, and failure of constrained macromolecular systems.

His research reframed nonlinear rheology by demonstrating that many hallmark responses of entangled polymer melts and solutions – stress overshoot, flow heterogeneity, yielding, and rupture – originate from intrinsic mechanical instabilities of the load-bearing network of topological constraints (uncrossability-induced entanglement), rather than from purely homogeneous constitutive behavior. Through carefully controlled rheological and velocimetric experiments, he and his students provided some of the clearest and most influential experimental evidence for shear banding in well-entangled polymer melts, thereby challenging long-standing assumptions that such materials necessarily flow homogeneously.

A lasting contribution of his work is the establishment of yielding and failure as genuine physical processes in polymeric liquids. By directly linking stress localization, sharp stress drops, and irreversible structural changes to the breakdown of the entangled network under large fast deformation, he introduced a stability-based and structure-based framework that unifies shear banding, stress overshoot, and rupture. This perspective has reshaped interpretation of both shear and extensional rheology and clarified the physical origin of nonlinear responses that had previously been treated largely through phenomenological constitutive modeling.

Wang has also made major contributions to nonlinear extensional rheology, demonstrating that rupture and strain-hardening behavior in entangled polymers reflect the intrinsic integrity and failure of the molecular constraint network, rather than being governed solely by capillary or geometric instabilities. His work further extended these ideas to polymer glasses and solid polymers, establishing deep conceptual connections between the nonlinear mechanics of entangled melts and the plasticity and failure of amorphous solids.

These contributions are synthesized and articulated in his authoritative monograph Nonlinear Polymer Rheology (Wiley, 2018), which has become a principal reference for the physics of nonlinear deformation, flow instability, yielding, and rupture in polymeric liquids.

More recently, Wang has taken a paradigm-changing approach to elastomeric fracture. In a Perspective published in Macromolecules, he proposed a new framework for elastomeric fracture to replace the prevailing paradigm of the past seven decades. This work clarifies long-standing misunderstandings and establishes a unifying connection between fracture, nonlinear rheology, and chain scission via covalent-bond dissociation in highly stretched polymer network – placing his contributions in direct continuity with the classic advances of Gent, Rivlin, and Smith in elastomer mechanics, and climaxing in an upcoming book Physics of Deformation, Fracture Mechanics and Adhesion in Polymers (Wiley, 2026).

Collectively, Shi-Qing Wang’s work has redefined the scientific foundations of nonlinear polymer rheology and fracture by unifying instability, yielding, and failure within a coherent, physically transparent framework grounded in molecular constraints and mechanical stability.