Using feedback control to actively regulate the healing rate of a self-healing process subjected to low cycle dynamic stress

• Published in: Smart materials and structures Vol. 25; no. 5; pp. 55028 - 55038
• Main Authors: Kuponu, O S, Kadirkamanathan, V, Bhattacharya, B, Pope, S A
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.05.2016
• Subjects: Active control; Adaptive control systems; Damage; Fault minimization; Feedback control; Healing; Propagation; Self healing materials; self-healing; smart materials
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/25/5/055028

Intrinsic and extrinsic self-healing approaches through which materials can be healed generally suffer from several problems. One key problem is that to ensure effective healing and to minimise the propagation of a fault, the healing rate needs to be matched to the damage rate. This requirement is usually not met with passive approaches. An alternative to passive healing is active self-healing, whereby the healing mechanism and in particular the healing rate, is controlled in the face of uncertainty and varying conditions. Active self-healing takes advantage of sensing and added external energy to achieve a desired healing rate. To demonstrate active self-healing, an electrochemical material based on the principles of piezoelectricity and electrolysis is modelled and adaptive feedback control is implemented. The adaptive feedback control compensates for the insufficient piezo-induced voltage and guarantees a response that meets the desired healing rate. Importantly, fault propagation can be eliminated or minimised by attaining a match between the healing and damage rate quicker than can be achieved with the equivalent passive system. The desired healing rate is a function of the fault propagation and is assumed known in this paper, but can be estimated in practice through established prognostic techniques.