Vibration characteristics of adhesive bonding repaired carbon fiber/epoxy laminate under hygrothermal condition

Abstract

Through theoretical derivation and finite element simulation, the vibration characteristics of composite laminate with four-edge clamped support under hygrothermal condition were studied. Based on the Mindlin first-order shear deformation theory and the Hamilton principle, taking the effect of hygrothermal stress into account and using the equivalence of temperature and humidity, the constitutive equation of composite laminate affected by the hygrothermal environment was derived. The finite element method was used to solve the vibration characteristic equation of the laminate. Bonding repaired laminate model was established by using the finite element software ABAQUS, and the model was compared with literature results. The effects of different hygrothermal environments and the number of additional patches on the vibration characteristic of the bonding repaired laminate were discussed. The results of the example show that in the hygrothermal environment, the introduction of additional patch reduces the natural frequencies of the various orders of the bonding repaired laminate. When the number of additional patches changes from one to two, the first-order natural frequency decreases further. The effect of increased humidity on natural frequency reduction is greater than that of temperature increase on natural frequency. In the environment where the temperature and humidity are simultaneously increased, the introduction of the additional patch will cause the bonding repaired laminate to reach the state of hygrothermal buckling earlier.

Keywords

• composite laminate
• bonding repair
• additional patch
• hygrothermal condition
• vibration characteristic