Eshelby-like forces in elastic structures: theory, experiments and applications

The Eshelbian force is the main concept of a celebrated theoretical framework associated with the motion of dislocations and, more in general, defects in solid. Similarly, it is proven that a force driving the configuration of an elastic structure is generated through the motion and release mechanism of flexural and torsional energy. This configurational force, analytically derived through different approaches and experimentally validated, provides counterintuitive but crucial effects in elasticity. In particular, it affects equilibrium paths in systems with variable length and instabilities, bifurcation and restabilization occurring in a structure penetrating in a movable constraint. Furthermore, this configurational force (called 'Eshelby-like' in analogy to continuum mechanics) opens a totally new perspective in the mechanics of deformable mechanisms, with possible broad applications in new weighing devices (the 'elastica arm scale'), torsional locomotion along perfectly smooth channel and configurational actuators, capable of transforming torque into propulsive force.