Multi-directional stiffness degradation induced by matrix cracking in composite laminates

2002 ◽  
Vol 24 (2-4) ◽  
pp. 119-125 ◽  
Author(s):  
X DUAN
Keyword(s):  
Composite Laminates ◽  
Matrix Cracking ◽  
Stiffness Degradation ◽  
Directional Stiffness

The effect of multi-directional stiffness degradation on the non-linear analysis of composite laminates

2012 ◽  
Vol 19 (2) ◽  
pp. 127-137
Author(s):  
Sung-Cheon Han ◽  
Won-Hong Lee ◽  
Weon-Tae Park
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Shell Element ◽  
Linear Analysis ◽  
Matrix Cracking ◽  
Stiffness Degradation ◽  
Non Linear ◽  
Directional Stiffness

AbstractA formulation of element-based Lagrangian 9-node shell element based modified first-order shear deformation theory is improved for non-linear behaviors of composite laminates containing matrix cracking. Using the refined ANS (assumed natural strain) shell elements either show the optimum combination of sampling points with an excellent accuracy or remove the locking phenomenon. The multi-directional stiffness degradation caused by matrix cracking, which was proposed by Duan and Yao, is conducted. Natural coordinate based higher-order transverse shear strains are used in the present shell element. Numerical examples demonstrate that the present element behaves reasonably satisfactorily either for the linear or geometrical non-linear analysis of laminated composite structures. The results of laminated composite shells with matrix cracking may be the benchmark test for the non-linear analysis of damaged composite laminates.

Experimental investigation of the fatigue behavior of glass/epoxy composites evaluated by the stiffness degradation and damage accumulation

2018 ◽  
Vol 53 (6) ◽  
pp. 731-740 ◽  
Author(s):  
Walid Roundi ◽  
Abderrahim El Mahi ◽  
Abdellah El Gharad ◽  
Jean-Luc Rebiere
Keyword(s):  
Composite Laminates ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Matrix Cracking ◽  
Stiffness Degradation ◽  
Cyclic Behavior ◽  
Loading Level ◽  
Applied Loading ◽  
Number Of Cycles ◽  
Core Characteristics

The present paper deals with the mechanical behavior of glass/epoxy composite materials under static and cyclic tensile loading. The tested specimens have been made with different stacking sequences ([02/902]s; [902/02]s; [03/90]s; [903/0]s) according to the vacuum infusion procedure. The results of this investigation show the static behavior of the tested laminated composites characterized by the strain to failure, Young's modulus and tensile strength. Wöhler curves corresponding to each stacking sequence were plotted in order to observe the evolution of the maximum stress Smax according to the number of cycles. Fatigue Tests were performed under various applied loading levels ( r), and these values were chosen to evaluate the effect of loading level on the stiffness degradation and damage growth in the tested specimens. Afterward the evolution of the global damage factor ( D) according to the number of cycles was calculated in function of the core characteristics, applied loading level ( r) and type of loading. The cyclic behavior of the composite laminates mainly depends on the progressive developments of damage mechanisms such as matrix cracking, delamination, and fiber breakage.

Numerical Investigation of a Stiffened Panel Subjected to Low Velocity Impacts

2015 ◽  
Vol 665 ◽  
pp. 277-280 ◽  
Author(s):  
Aniello Riccio ◽  
S. Saputo ◽  
A. Sellitto ◽  
A. Raimondo ◽  
R. Ricchiuto
Keyword(s):  
Numerical Investigation ◽  
Composite Laminates ◽  
Mechanical Response ◽  
Numerical Study ◽  
Fem Analysis ◽  
Matrix Cracking ◽  
Stiffened Panel ◽  
Low Velocity ◽  
Formation And Evolution ◽  
The Impact

The investigation of fiber-reinforced composite laminates mechanical response under impact loads can be very difficult due to simultaneous failure phenomena. Indeed, as a consequence of low velocity impacts, intra-laminar damage as fiber and matrix cracking and inter-laminar damage, such as delamination, often take place concurrently, leading to significant reductions in terms of strength and stability for composite structure. In this paper a numerical study is proposed which, by means of non-linear explicit FEM analysis, aims to completely characterize the composite reinforced laminates damage under low velocity impacts. The numerical investigation allowed to obtain an exhaustive insight on the different phases of the impact event considering the damage formation and evolution. Five different impact locations with the same impact energy are taken into account to investigate the influence on the onset and growth of damage.

Prediction of stiffness degradation in hygrothermal aged [θm/90n]S composite laminates with transverse cracking

2008 ◽  
Vol 199 (1-3) ◽  
pp. 199-205 ◽  
Author(s):  
E.A. Adda-bedia ◽  
M. Bouazza ◽  
A. Tounsi ◽  
A. Benzair ◽  
M. Maachou
Keyword(s):  
Composite Laminates ◽  
Stiffness Degradation ◽  
Transverse Cracking

NUMERICAL PREDICTION OF STIFFNESS DEGRADATION OF THIN-PLY CFRP LAMINATES UNDER FATIGUE LOADING

2021 ◽  
Author(s):  
RYOMA AOKI ◽  
RYO HIGUCHI ◽  
TOMOHIRO YOKOZEKI
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Crack Density ◽  
Continuum Damage Mechanics ◽  
Fatigue Loading ◽  
Stiffness Degradation ◽  
Cfrp Laminates ◽  
Mechanics Model ◽  
Element Simulation ◽  
Proposed Model

This study aims to conduct a fatigue simulation for predicting the stiffness degradation of thin-ply composite laminates with several ply thicknesses. For the simulation, a fatigue evolution model of intra-laminar damage in thin-ply composite laminates considering the effect of ply thickness was proposed. The intra-laminar damage evolution was modeled using the continuum damage mechanics model and the static and fatigue evolution law were formulated by relating the transverse crack density to the damage variable. The finite element simulation using the proposed model was conducted to predict the stiffness degradation of the laminates as a function of the number of loading cycles. The simulation results show that the experimental data can be reproduced by using the proposed fatigue model.

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