Three-dimensional Orthogonal Woven Research Articles

Micro/meso-scale damage analysis of three-dimensional orthogonal woven composites based on sub-repeating unit cells

The mechanical responses including damage mechanisms for surface and interior parts of three-dimensional orthogonal woven composite have been analyzed by the multi-scale finite element method. Based on fabric architecture and fiber volume fraction in the three-dimensional orthogonal woven composite, the meso-scale repeating unit cells model and micro-scale repeating unit cell model are established. The periodic boundary conditions are applied to the micro-repeating unit cell and meso-repeating unit cell models. Appropriate failure criteria and a post-damage constitutive model are used to simulate the failures of fiber/fiber-bundles and resin in the micro/meso-scale repeating unit cells. A new elastic material model with damage propagation is defined with the user-defined material subroutine in commercial finite element software package ABAQUS/Standard. Mechanical behaviors including initiation and propagation of damage in micro/meso repeating unit cells under different loadings have been simulated with the user-defined material subroutine and the ABAQUS/Standard. The simulation results are compared with the experimental observations and they are in good agreement.

Performance and impact damage of a three dimensionally integrated microstrip feeding antenna structure

Abstract A three dimensionally integrated microstrip antenna (3DIMA) with microstrip feeding was fabricated and analyzed. In this design concept, a microstrip antenna was woven into the three-dimensional orthogonal woven composite for the load-bearing while functioning as an antenna. The simulation work was done using the antenna simulation software before fabrication. The measured voltage standing wave ratio (VSWR) of the antenna was 1.18 at the resonant frequency of 1.31 GHz. The measured radiation pattern had a maximum value at 0°, which agreed well with the simulation results. In addition, impact tests were performed with the impact energy ranging from 0 J to 15 J. The results showed that the VSWR changed little even at 15 J impact energy demonstrating good impact resistance and structural integrity of the antenna structure.

Transverse Impact Damage and Energy Absorption of Three-Dimensional Orthogonal Hybrid Woven Composite: Experimental and FEM Simulation

This article presents transverse impact behavior of 3D orthogonal Twaron ®/glass hybrid woven composite both in experimental and FEM simulation. The transverse impact behaviors of the 3D woven composite along warp and weft direction were tested with a modified Split Hopkinson Pressure Bar (SHPB) apparatus. The load—displacement curves and damage morphology were obtained to analyze the energy absorptions and impact damage mechanisms of the composite under different impact velocities. A unit-cell model based on the microstructure of the 3D woven composite was established to determine the composite deformation and damage when the composite impacted by a hemisphere-ended steel rod. Incorporated with the unit-cell model, a elasto-plastic constitute equation of the 3D woven composite and the Critical Damage Area (CDA) failure theory of composites have been implemented as a User Defined Material law (VUMAT) for ABAQUS/Explicit. The FEM calculated load—displacement curves, impact deformations and damages are compared with those in experiment. The good agreements of the comparisons prove the validity of the unit-cell model and user-defined subroutine VUMAT. This manifests the applicability of the VUMAT to the design of the 3D orthogonal woven composite structures under other impulsive loading conditions.

Transverse impact behavior and energy absorption of three-dimensional orthogonal hybrid woven composites

Abstract The transverse impact behaviors of three-dimensional (3D) orthogonal hybrid woven fabric composites were tested on a modified split Hopkinson pressure bar (SHPB) apparatus. The load–displacement curves of the composites in transverse impact were obtained to analyze the strain rate sensitivity of energy absorption. It was found that energy absorption of the composites increases with the impact velocity (i.e., strain rate). The failure modes under quasi-static transverse loading are tensile failure on back side and compressive failure on the front side, while those in transverse impact are matrix cracking, fiber breakage and fiber pull-out. The 3D orthogonal woven composites have the same failure mode in the warp and weft directions. There is no delamination for the 3D orthogonal woven composites under transverse impact as observed in laminated composites.

Energy absorptions and failure modes of 3D orthogonal hybrid woven composite struck by flat-ended rod

Three-dimensional (3D) orthogonal woven composite has high stiffness, strength, and energy absorption capacity along X, Y, and Z directions because there are no crimps in yarn. This paper presents mechanical behaviors and energy absorptions of the 3D orthogonal hybrid woven composite under transverse impact and quasi-static loading by flat-ended rod. The failure load and energy absorption of the composite increase with the increase in loading rate. The damage morphology of the composite coupon manifests the compression failure in the front side and tension failure in rear side. There are no delaminations in the composite coupons for both quasi-static and impact loading for the existence of Z-yarn in fabric structure. This phenomenon manifests the potential application of the 3D orthogonal woven composite to impact resistance areas. POLYM. COMPOS., 27: 410–416, 2006. © 2006 Society of Plastics Engineers

An Analytical Method for Thermoelastic Analysis of 3D Orthogonal Interlock Woven Composites

A three-dimensional woven composite thermoelastic model is presented for predicting the thermoelastic properties of three-dimensional orthogonal interlock woven composites. The model is based on two level discretization of the repeating unit cell. The repeating unit cell is discretized into sections, elements, subsections and subelements. Eight number architectures of three-dimensional orthogonal woven composites have been analyzed. Compliance averaging and stiffness averaging schemes have been used for the prediction of thermoelastic properties. For the same fiber volume fraction, three-dimensional orthogonal interlock woven composites show a significant increase in through-the-thickness properties without a comparable reduction in the in-plane properties.

Evaluation of thermo-elastic properties of three-dimensional orthogonal woven composites

A homogenisation scheme is developed to evaluate the thermo-elastic properties of three-dimensional orthogonal woven composites. The coupling effects between thermal and mechanical behaviour in different directions are taken into account. In comparison to some other analytical models, the results obtained with the present scheme are shown to be in better agreement with FEM predictions and experimental data. In addition, effects of cross-sectional geometry of yarns on the thermo-elastic properties of the composites are also analysed.

Stress and Failure Analysis of 3D Orthogonal Interlock Woven Composites

A three-dimensional woven composite strength model is presented for predicting the failure behavior of three-dimensional orthogonal interlock woven composites under on-axis uniaxial static tensile loading and shear loading. The model is based on two-level discretization of the repeating unit cell. The repeating unit cell is discretized into sections, elements, subsections and subelements. The model predicts the stress levels at which the secondary failures take place at subelement level. The effect of secondary failure is considered for further analysis and the ultimate tensile strength and shear strength and the corresponding strains are predicted. A parametric study has been carried out for different 3D orthogonal interlock woven composite configurations. In general, it is seen that there is no significant reduction in the inplane elastic and strength properties for 3D orthogonal woven composites, compared to the corresponding cross-ply laminates made of unidirectional layers, but there is a significant increase in the through-the-thickness properties.

Stress and Failure Analysis of 3D Orthogonal Interlock Woven Composites

A three-dimensional woven composite strength model is presented for predicting the failure behavior of three-dimensional orthogonal interlock woven composites under on-axis uniaxial static tensile loading and shear loading. The model is based on two-level discretization of the repeating unit cell. The repeating unit cell is discretized into sections, elements, subsections and subelements. The model predicts the stress levels at which the secondary failures take place at subelement level. The effect of secondary failure is considered for further analysis and the ultimate tensile strength and shear strength and the corresponding strains are predicted. A parametric study has been carried out for different 3D orthogonal interlock woven composite configurations. In general, it is seen that there is no significant reduction in the inplane elastic and strength properties for 3D orthogonal woven composites, compared to the corresponding cross-ply laminates made of unidirectional layers, but there is a significant increase in the through-the-thickness properties.

Models for Predicting Thermomechanical Properties of Three-Dimensional Orthogonal Woven Composites

Unit cell and laminate modeling approaches were previously developed for predicting the effective elastic constants of three-dimensional (3D) orthogonal woven fabric composites [1]. For both models, the finite element analysis (FEA) and theoretical analysis methods were proposed. In the FEA method, finite element meshes were generated using the commercial FEA software Strand6, while in the theoretical analysis methods, closed-form formulas were derived using elastic mechanics theory and the "X model," "Y model" and "Z model" [2]. In this paper, both the unit cell and laminate modeling approaches were used to predict the effective coefficients of thermal expansion (CTEs) for 3D orthogonal woven fabric composites. The present numerical study showed that there is a good agreement between the FEA and theoretical analysis results. Also, a good agreement was noted between the present predicted results and experimental results available in the literature. Parametric studies were conducted to investigate the effects of the yarn cross-sectional shape, lamina block layer number, lamina block thickness, through-the-thickness (or z) yarn volume fraction and its space (i.e., space between two adjacent z yarns) on the effective coefficients of thermal expansion. It is worth pointing out that the theoretical models and the relevant formulas for predicting the effective coefficients of thermal expansion can also be used to predict the effective coefficients of moisture expansion for 3D orthogonal woven fabric composites.