Morphology and interaction between components for Ag nano-particles dispersed poly （vinyl alcohol） （PVA） composites were investigated. For this purpose, both PVA and Ag NO₃ aqueous solutions were mixed and cast. The dried films were irradiated with ultraviolet ray in order to reduce Ag⁺ion to Ag. From a transmission electron microscopic observation for ultrathin sections, 5-10 nm sized Ag particles were dispersed in PVA in the range of about 20wt％ of Ag loading. The agglomerations of Ag particles were observed at 33wt％ of Ag loading. From a dynamic mechanical analysis, the Ag loadingneverinfluencedontheglasstransitiontemperatureofPVA.From athermogravimetric analysis, the clear improvement of thermal stability of PVA was observed in the range of optimal Ag loading. However, this improvement was also observed in the HNO₃ added PVA.¹H pulse nuclear magnetic resonance analysis showed no evidence of interaction between the components.

Stepped-lap adhesive joints with similar solid and hollow cylinder adherends under static bending moments are analyzed using 3-DFEM.The effects of adhesive Young's modulus, the adhesive thickness,scarf angle,and then umber of steps on the interface stress distributions are examined.The code of FEM employed is ANSYS.The maximum principal stress　σ₁is singular at the outside edge of the interfaces for both of the similar solid cylinder and hollow cylinder joint,while,the value of σ₁ is larger at the outside diameter than that at the inside diameter for the similar hollow cylinder joints. The value of σ₁ decreases as the adhesive thickness decreases and as adhesive Young's modulus, the number of steps and the scarf angle increase. The bending moments when the joints rupture are predicted using the measured stress-strain curve of the adhesive.The predicted ruptured bending moments for the both joints are in a fairy good agreement with the measured results. It is found that the rupture dbending moment for similar solid cylinder joints is slightly larger than that for similar hollow cylinder joints