Strength Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods

2010 ◽  
Vol 160-162 ◽  
pp. 81-86
Author(s):  
Feng Liu
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Principal Direction ◽  
Tensile Force ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surface Patch ◽  
Damage Mode ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

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.

Three Dimensional Finite Element Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Scarf Bonding Method

2010 ◽  
Vol 26-28 ◽  
pp. 370-375
Author(s):  
Feng Liu ◽  
Wen Feng Qin ◽  
Guo Chun Liu
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Principal Direction ◽  
Tensile Force ◽  
Three Dimensional ◽  
Element Model ◽  
Damage Mode ◽  
Bismaleimide Resin ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

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 model of the same laminates with non-penetrating damage repaired by scarf bonding method is built, and the stress state is also analyzed. The strength criterion and the damage mode of the scarf bonding composite laminates are also given. The strength and the damage mode of original laminates are compared with that of the laminates with non-penetrating damage. 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 made of carbon fiber reinforced bismaleimide resin and the repaired one both damage first in the laminar whose second material principal direction coincides with the axial tensile force. And the damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the laminates repaired by scarf bonding. After scarf bonding repair, the strength of the damaged laminates can recover up to about eighty-four percent.

Strength Analysis of Damaged Composite Laminates Repaired by Scarf Bonding Method Based on Three Dimensional Model

2010 ◽  
Vol 44-47 ◽  
pp. 2219-2223
Author(s):  
Feng Liu
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Principal Direction ◽  
Tensile Force ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Element Model ◽  
Damage Mode ◽  
Bonding Method ◽  
Three Dimensional Finite Element

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 presented based on finite element analysis. The strength criterion and initial damage mode are given based on the stresses of material principal direction. The three dimensional finite element model of the same laminates with non-penetrating damage repaired by scarf bonding method is built, and the stress state is also analyzed. Annular solids are used to simulate the resin between the mother laminates and the patches. The strength criterion and the damage mode of the scarf bonding composite laminates are also given. The strength and the damage mode of original laminates are compared with that of the repaired laminates. The influence of the annular shape resin is considered in the repaired model. 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 one both damage first in the laminar whose second material principal direction coincides with the axial tensile force. And the damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the repaired laminates. After scarf bonding repairing, the strength of the damaged laminates can recover up to about 88%.

Characterization of delamination-type damages in composite laminates using guided wave visualization and air-coupled ultrasound

2016 ◽  
Vol 16 (2) ◽  
pp. 142-152 ◽  
Author(s):  
Rabi S Panda ◽  
Prabhu Rajagopal ◽  
Krishnan Balasubramaniam
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Guided Wave ◽  
Finite Element Simulations ◽  
Wave Refraction ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Lamb Wave Propagation

This article reports on the characterization of delamination damages in composite laminates using wave visualization method. A combination of plate-guided ultrasound and air-coupled ultrasonics is used to locate and visualize delaminations. The study focuses on the physics of Lamb wave propagation and interaction with delaminations at various through-thickness locations and positions. Three-dimensional finite element simulations are used to study, in detail, the changes in wave features such as mode velocity, wavelength and wave refraction in the delamination region. These wave features provide information on the location, position and orientation of the delamination. These studies are validated by experimental measurements. The influence of position of source and delamination on wave refraction in the delamination region is examined. This method also correlates the results obtained from experiments and finite element simulations to theoretical dispersion curves in order to distinctly determine the delamination location.

scholarly journals Evaluation of the Ko-Len Model for Enterlaminar Stresses in Composite Laminates with an Open Hole

1996 ◽  
Vol 5 (5) ◽  
pp. 096369359600500 ◽  
Author(s):  
F. Z. Hu ◽  
C. Soutis
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Tensile Loading ◽  
Stress Distributions ◽  
Element Analysis ◽  
Open Hole ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The purpose of this paper is to evaluate a recently developed analytical model [1] which determines the interlaminar stress distributions around a circular hole in symmetric composite laminates under in-plane tensile loading. For this purpose, a three-dimensional finite element analysis is performed and the stress distributions for symmetric cross-ply laminates are presented This work is relevant to the prediction of delamination onset load and location around the discontinuity.

Natural Vibration Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods

2010 ◽  
Vol 160-162 ◽  
pp. 87-90
Author(s):  
Feng Liu ◽  
Zhong Bo Zhang ◽  
Jun Yan
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Composite Laminates ◽  
Natural Vibration ◽  
Three Dimensional ◽  
Vibration Frequencies ◽  
Dimensional Finite Element ◽  
Surface Bonding ◽  
Bonding Method ◽  
Three Dimensional Finite Element

The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the natural vibration of the square composite laminates with clamped edges is analyzed. The natural vibration frequencies and modes of laminates without damage are given based on finite element method. The three dimensional finite element models of the same square laminates with non-penetrating damage repaired by two kinds of bonding methods are built. The natural vibration frequencies and modes are also given. 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 natural vibration frequencies of the composite laminates all increase after it is repaired either by scarf bonding method or scarf and surface bonding method. After scarf bonding repairing, the lowest natural frequency increases about 3.6% and the second natural frequency increases 3.7%. After scarf and surface bonding repairing, the lowest natural frequency increases about 4.5% and the second frequency increases about 6.4%. The natural vibration modes of different repairing models are similar. The increase of natural frequencies may cause temporary vibration of aircraft skin made of composite laminates. The risk of resonance caused by bonding repairing is small.

Sign in / Sign up

Export Citation Format

Share Document