Three-dimensional moisture diffusion in laminated composites

1977 ◽  
Author(s):  
J. WHITNEY
Keyword(s):  
Laminated Composites ◽  
Three Dimensional ◽  
Moisture Diffusion

scholarly journals Impact Resistance Study of Three-Dimensional Orthogonal Carbon Fibers/BMI Resin Woven Composites

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4376
Author(s):  
Yanqi Hu ◽  
Zekan He ◽  
Haijun Xuan
Keyword(s):  
Carbon Fibers ◽  
High Efficiency ◽  
Laminated Composites ◽  
Impact Resistance ◽  
Three Dimensional ◽  
High Strength ◽  
Woven Composites ◽  
Failure Behavior ◽  
Bismaleimide Resin ◽  
Modeling Strategy

Three-dimensional woven composites have been reported to have superior fracture toughness, fatigue life and damage tolerance compared with laminated composites due to through-thickness reinforcement. These properties make them lighter replacements for traditional high-strength metals and laminated composites. This paper will present impact resistance research on three-dimensional orthogonal woven composites consisting of carbon fibers/bismaleimide resin (BMI). A series of impact tests were conducted using the gas gun technique with the impacted target of 150 mm × 150 mm × 8 mm (length × width × thickness) and the cylindrical titanium projectile. The projectile velocity ranged from 180 m/s to 280 m/s, generating different results from rebound to perforation. This paper also presents a multiscale modeling strategy to investigate the damage and failure behavior of three-dimensional woven composites. The microscale and mesoscale are identified to consider the fiber/matrix scale and the tow architecture scale respectively. The macroscale model was effective with homogenized feature. Then a combined meso-macroscale model was developed with the interface definitions for component analysis in the explicit dynamic software LS-DYNA. The presented results showed reliable interface connection and can be used to study localized composites damage at a relatively high efficiency.

Mechanical Behavior of Laminated Composites with Circular Holes

2013 ◽  
Vol 550 ◽  
pp. 1-8 ◽  
Author(s):  
Habib Achache ◽  
Benali Boutabout ◽  
Djamel Ouinas
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Composite Structures ◽  
Laminated Composites ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Element Formulation ◽  
Composites Materials ◽  
Circular Holes ◽  
Fibers Orientation

This paper presents a numerical method for the evaluation of the stress concentration factor (SCF) in three dimensional laminated composites under mechanical loads. The proposed method uses the finite element formulation. The composites materials based on the epoxy matrix and reinforcing fibers are extensively used in aircraft structures due to their high specific characteristics. However, the withstanding of composite structures can be significantly reduced by the addition of geometric singularities, such as perforations or notches. To Analyses the stress concentration around geometrical notches, several studies as analytical, numerical and experimental techniques are available. The stress distribution in a laminated composite plate with the presence of a circular hole was investigated using the finite element method. In order, the results obtained by this study are compared with those reported in literature. The aim of this analysis is to evaluate numerically the factor of stress concentration under the influence of several parameters such as fibers orientation, the mechanical characteristics of composites and the distance between notches of cross-laminated.

Three-Dimensional Effective Moduli of Orthotropic and Symmetric Laminates

1992 ◽  
Vol 59 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Ajit K. Roy ◽  
Stephen W. Tsai
Keyword(s):  
Laminated Composites ◽  
Three Dimensional ◽  
Shear Stiffness ◽  
Accurate Method ◽  
Homogeneous System ◽  
Solution Technique ◽  
Stacking Sequence ◽  
Effective Moduli ◽  
Function Solution ◽  
Interlaminar Shear

A simple and accurate method for estimating the three-dimensional effective moduli of symmetric and orthotropic laminated composites is presented. The method is based on obtaining the exact displacement field of three boundary value problems of laminated composites using the Airy stress function solution technique. The effective moduli are estimated by matching the boundary displacements of the equivalent homogeneous system with those of the laminated system. Among the estimated effective moduli, those associated with the interlaminar direction are of special interest. It is found that the effective interlaminar normal stiffness in extensional deformation is independent of laminae stacking sequence which is consistent with the finding of Pagano (1974). However, the laminate interlaminar shear stiffness is dependent on stacking sequence, and it is shown that the rule of mixtures can not predict the interlaminar shear stiffness accurately.

Simulation of slitting method for calculation of compliance functions of laminated composites

2011 ◽  
Vol 46 (9) ◽  
pp. 1101-1109 ◽  
Author(s):  
Mahmood M Shokrieh ◽  
Saeed Akbari R
Keyword(s):  
Finite Element ◽  
Laminated Composites ◽  
Three Dimensional ◽  
Slit Width ◽  
Orthotropic Materials ◽  
Complete Agreement ◽  
Slitting Method ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Compliance Coefficients

In this research, the process of slitting with an assumed residual stress distribution is simulated to calculate compliance functions of laminated composites. The primary aim of this article is to investigate different parameters influencing the calculation of compliance coefficients for laminated composites using a finite element model. First, using two- and three-dimensional finite element models, the process of slitting in isotropic materials for calculating the compliance coefficients is simulated. The results show a complete agreement between the two models. Also, the results of simulation show that in the modeling of slitting method for laminated composites, real slit width must be considered. That is because composite laminates are generally thin and slitting in these materials results in large slit width to thickness ratio. Finally, the developed simulation method is applied to calculate compliance coefficients for two carbon/epoxy- and glass/epoxy-laminated composites with quasi-isotropic and cross-ply lay-ups using a three-dimensional finite element modeling. For a better precision, a full three-dimensional model without symmetry assumption is considered. The presented method is capable of simulating slitting method in parts and specimens with complicated geometry as well as in orthotropic materials with any degree of orthotropy.

Improvement of interlaminar shear strength of 2.5D fabric laminated composites with short-cut web interlayer

2017 ◽  
Vol 37 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Leilei Song ◽  
Jialu Li ◽  
Yufen Zhao ◽  
Xiaoming Chen ◽  
Li Chen
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Laminated Composites ◽  
Three Dimensional ◽  
Interlaminar Shear Strength ◽  
Bending Properties ◽  
Bending Tests ◽  
Testing Method ◽  
Short Beam ◽  
Interlaminar Shear

Abstract In this study, the short-cut web interlayer and three-dimensional (3D) needle-punched technique were used to improve the interlaminar shear strength (ILSS) of 2.5D fabric laminated composites. The ILSS was measured by the short beam testing method, and the tensile and bending tests were carried out to investigate the in-plane mechanical properties. Observations on microstructure and crack propagation were carried out. The damage mechanisms of different 2.5D fabric laminated composites were analyzed. The results showed that the short-cut web interlayer and 3D needle-punched technique resulted in the improvement of ILSS, and they affected the tensile and bending properties of 2.5D fabric laminated composites.

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