[15p-P1-1~9] 1.5 Instrumentation, measurement and Metrology

[15p-P1-9] Direct and indirect visualization of stress distribution in adhesive layer

〇Nao Terasaki¹, Yuki Fujio¹, Yoshitaro Sakata¹ (1.AIST)

Keywords:mechanoluminescence, adhesive, visualization

Elasticoluminescent material is a novel ML functional ceramic powder (controllable size: 10 nm-100 μm, representative and the most efficient ML material: SrAl₂O₄:Eu²⁺) and it can emit intensive light repeatedly accompanied by mechanical stress such as deformation, friction, impact, even in elastic deformation region. The ML intensity is proportional to strain energy of the material. Thus, when dispersedly coated onto a structure, each particle acts as a sensitive mechanical sensor, while the two-dimensional (2D) emission pattern of the whole assembly reflects the dynamical strain/stress distribution inside the structure and the mechanical information around the defect and crack or the in-visible tip. Here, we would like to report on suitability of the ML sensing for diagnosing a stress distribution in adhesive, adhesion strength between metal interface and adhesive, and a stress contribution of adhesive and fiber in CFRP (carbon fiber reinforced plastic). As the result, we succeeded to directly visualize stress distribution related to adhesion and find out the area of pseud kissing bond, area of non-bonding condition, through mechanoluminescence.