Strength Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods
The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the stress state of the composite laminates under unidirectional tensile force is analyzed. The strength criterion and damage mode are given based on the stresses of material principal direction. The three dimensional finite element models of the same laminates with non-penetrating damage repaired by two kinds of bonding methods are built. The strength criterion and the damage mode of the two kinds of repaired models are also given. The influence of the interlaminar stress is considered in these analysis models. It is showed that the three dimensional models can simulate the geometric and physical features of the real composite laminates. It is concluded that the original composite laminates and the repaired ones both damage first in the laminar whose second material principal direction coincides with the axial tensile force. The damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the mother laminates. After scarf bonding repair, the strength of the damaged laminates recovers up to about eighty-four percent. With additional surface patch, the strength of the damaged laminates recovers up to about eighty-nine percent. Surface patch can improve the strength of damaged laminates.
Guojun Zhang and Jessica Xu
F. Liu "Strength Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods", Advanced Materials Research, Vols. 160-162, pp. 81-86, 2011