複合材料中の層間接着強度に及ぼす残留応力の影響

抄録

This review introduces how affect the residual stress in composites on its interlayer adhesive strength. Thesimple evaluation method of residual stress in resin products is also explained. The carbon fiber reinforcedthermo-plastics（ CFRTP） was fabricated by stacking and heat pressing the plain woven carbon cloth and thinsheetof PA6. For evaluation of interlayer adhesive strength, the simulated interlayer was prepared by insertingthe thin polyimide sheet before heat pressing. The needle with hemispherical tip was vibrated to axial directionby using ultrasonic transducer. The vibrated needle was stabbed to CFRTP toward thickness direction byusing CNC controlled XYZ table. By applying the tensile load to the simulated interlayer, the adhesive strengthwas evaluated. Test results showed that the interlayer adhesive strength of CFRTP was improved when needlewas stabbed with appropriate velocity. The improvement in adhesive strength was depending on the area ofsimulated interlayer. The hardness distribution measured by using model specimen revealed that the hardnessof model specimen around stabbed point was improved. The hardness measurement of resin under uni-axialstress revealed that the hardness of resin shows almost inverse linear relationship. These results suggestedthat the existence of compressive residual stress due to ultrasonic needle punching improves the interlayeradhesive strength of CFRTP.