Abstract: An object is to provide a joining state detection film, a joining state detection device, and a joining state detection method, capable of detecting a joining state of a joining portion of two members from the outside. [Solution]A film containing a mechanoluminescent substance is formed on a surface, on a side opposite to a joining surface, of at least one member of two members that are joined at joining parts each having the joining surface, and physical stimulation is applied thereto.

Abstract: A light emitting structure light in response to a load applied to an object from a load object. In the light emitting structure are formed contacting portions which are provided on a supporting surface of the object, and which have a predetermined length from the surface of the supporting surface in a direction perpendicular to the surface of the object, wherein a stress-luminescent material is included in at least a portion of the supporting surface and the surface of the contacting portions.

Abstract: To provide a fracture-visualization sensor capable of visualizing the fracture behavior of a composite material and a composite-material fracture-visualization system using the fracture-visualization sensor. A first luminescent film including a mechanoluminescent material is provided on one surface of a composite material. The first luminescent film has a maximum stress per unit of cross-sectional area within the range of 19-43 N/mm2.

Abstract: To provide a fracture-visualization sensor capable of visualizing the fracture behavior of a composite material and a composite-material fracture-visualization system using the fracture-visualization sensor. A first luminescent film including a mechanoluminescent material is provided on one surface of a composite material. The first luminescent film has a maximum stress per unit of cross-sectional area within the range of 19-43 N/mm2.

Abstract: An object is to provide a joining state detection film, a joining state detection device, and a joining state detection method, capable of detecting a joining state of a joining portion of two members from the outside. [Solution] A film containing a mechanoluminescent substance is formed on a surface, on a side opposite to a joining surface, of at least one member of two members that are joined at joining parts each having the joining surface, and physical stimulation is applied thereto.

Abstract: PROBLEM TO BE SOLVED Under conventional methods, calculation for determining the extent of damage progression inside a structural body by computation is difficult to apply in actual practice, and also time consuming. In addition, detection of damage occurring in objects with complicated shapes or infinitesimal damage is particularly difficult. SOLUTION When pressure applied from one surface of an object to be measured to another surface thereof is pressurized or depressurized, the distance d1 between two distorted sections R1, R2 due to damage formed on the other surface S, is detected and the extent of the said damage progression is measured.