Prof. Seunghwa Ryu’s research team develops coupled electrical resistance measurement and IR thermography system for monitoring of damage in composite materials
(left)Ph.D candidate Kundo Park (Right)Professor. Seunghwa Ryu
Figure 1. Characterization of three ‘damage levels’ of GFRP through 3-channel tensile test where IR thermography and electrical resistance measurement are used simultaneously.
Figure 2. Thermal maps captured at different instants during the 3-channel tensile test of GFRP
Figure 3. Understanding of damage characteristic in each of the three damage levels obtained from multiphysics simulation.
The research team led by Prof. Seunghwa Ryu proposed a coupled non-destructive structural health monitoring method in which IR thermography and electrical resistance measurement are simultaneously employed to precisely evaluate both the onset and the spatial distribution of damage in composite material.
Existing researches that applied IR thermography alone for structural health monitoring of materials showed that despite its capability of evaluating the spatio-temporal distribution of internal damage formation, the detecting of permanent damage initiation in the material at its early deformation stage was not successful. In this research, a coupled health monitoring system in which IR thermography and electrical resistance measurement are simultaneously employed is proposed not only to capture the spatial distribution of damage, but to detect the moment of onset of damage as well.
Furthermore, the coupled system is applied to a uniaxial tensile test of CNT-doped GFRP and the result highlighted that the deformation and fracture process of GFRP could be divided into three different stages; here named ‘Damage levels’. To understand the physical phenomena in the material during each of the damage levels, they developed and employed a multi-physics simulation where mechanical, thermal, and electrical response of a material during its deformation can be modelled. The result exhibited that the three damage levels (I-III) can be characterized by the I) linear elasticity, II) accumulation of microdamage, and III) macro-scale crack propagation.
The result of present study will be published in Carbon, an international journal in composite materials, in September with Kundo Park, a Ph. D. candidate, as the first author. This research was co-advised by Prof. Seunghwa Ryu and Prof. Flavia Libonati in University of Genoa. (Paper title: Coupled health monitoring system for CNT-doped self-sensing composites)