Numerical study of the heating effects of high intensity focused ultrasound on shape memory polymer fiber reinforced self-healing polymer composite

Abstract

In polymer composites, constrained shape recovery, either by shape memory polymer (SMP) matrix or embedded SMP fibers, is utilized to close wide-opened cracks, followed by molecular scale healing either extrinsically or intrinsically, the so-called close-then-heal strategy. The most popular means to trigger shape recovery and healing is by heating. In this study, the potential for using high intensity focused ultrasound as a trigger for shape memory effect and self-healing of an SMP fiber-reinforced thermosetting polymer composite was explored. The objectives of the study were achieved via a finite element simulation in COMSOL Multiphysics. Simulation results showed that for an 8 mm thick, 18 mm long model composite with 5.8% SMP fiber volume fraction, a temperature rise of up to 5.6 K was obtained in the embedded SMP fiber after 2 s with only 1 s of the insonation. It was found that heat generation occurred at the fiber–matrix interfaces; however, subsequent temperature rise within the embedded fibers was achieved via conventional thermal conduction from the high-temperature interfacial regions into the fibers. The effect of specimen length, thickness, and fiber volume fraction on temperature rising was also evaluated. This study provides a better understanding of using ultrasound to trigger self-healing of SMP fiber-reinforced polymer composites.

Zwitterionic Poly(aryl ether ketone) with Water-Actuated, Reshaping-Reconfiguration Ability and Triple Shape Memory Effect

“…In stage II of the shape recovery process, SMPs spontaneously recover to the original shape while the temperature reaches the transition temperature again. These unique shape fixity and recovery behaviors endow SMPs with wide applications, such as biomedical tissues, electronic devices, and aerospace structures. − …”

Enhanced Shape Memory Metal-Coordinated Poly(aryl ether ketone)s with Tunable Gradient-Deformation Behaviors as well as Self-Healing and Reprocessing Abilities

“…In this stage, the temporary shape of SMPs could be obtained by the external force. Rigid regions, composed of rigid segments, chain entanglements, crystalline phases, and crosslinking points, are involved in the structural stability and recovery of permanent shape. − Programable deformation ability allows SMPs to be widely used in fields, such as biomedical tissues, smart actuators, electronic devices, and aerospace structures, − which could be triggered by diverse external stimuli, including heat, light, electricity, magnetic field, and solvent . Nevertheless, SMPs, such as polylactic acid, − polyurethane, − and polycaprolactone, − with excellent self-deformation ability, usually exhibit the weak mechanical performances and poor thermal stability, which restrict their applications in engineering structures.…”