3D Orthogonal Woven Composites Research Articles

Multi-Directional Compression Behaviors and Failure Mechanisms of 3d Orthogonal Woven Composites: Parametric Modeling and Strength Prediction

Multi-Directional Compression Behaviors and Failure Mechanisms of 3d Orthogonal Woven Composites: Parametric Modeling and Strength Prediction

Multiscale Analysis of Mechanical Properties of 3D Orthogonal Woven Composites with Randomly Distributed Voids.

Voids are common defects in 3D woven composites because of the complicated manufacturing processes of the composites. In this study, a micro–meso multiscale analysis was conducted to evaluate the influence of voids on the mechanical properties of three-dimensional orthogonal woven composites. Statistical analysis was implemented to calculate the outputs of models under the different scales. A method is proposed to generate the reasonable mechanical properties of the microscale models considering randomly distributed voids and fiber filaments. The distributions of the generated properties agree well with the calculated results. These properties were utilized as inputs for the mesoscale models, in which void defects were also considered. The effects of these defects were calculated and investigated. The results indicate that tensile and shear strengths were more sensitive to the microscale voids, while the compressive strength was more influenced by mesoscale voids. The results of this study can provide a design basis for evaluating the quality of 3D woven composites with void defects.

Modeling tensile behavior of 3D orthogonal woven green composites considering variability of natural fibers

Over the past few decades, ecological concerns resulted in an interest in using natural fibers such as flax and hemp as a reinforcement in composite materials. However, the inherent variability of their mechanical and physical properties complicates predicting the mechanical performance of their preforms and hence composites. This research introduces a novel approach in modeling natural fiber composites. To the best of the author's knowledge, this is the first model that considers the variability of natural fibers' properties used in 3D orthogonal woven composites. Measured properties of fibers, yarns and resin in addition to geometrical parameters were used as inputs while the entire Load-Elongation curve of the composite was the output of the model. This model is generalized for any weave design and can be applied for hybrid structures. The model was verified experimentally using preforms from flax and hemp fibers. The model verification showed that there is a better agreement between the predicted and experimental results when using the properties of yarns as input rather than fibers.

Maximizing the Performance of 3D Printed Fiber-Reinforced Composites

Fiber-reinforced 3D printing technology offers significant improvement in the mechanical properties of the resulting composites relative to 3D printed (3DP) polymer-based composites. However, 3DP fiber-reinforced composite structures suffer from low fiber content compared to the traditional composite, such as 3D orthogonal woven preforms solidified with vacuum assisted resin transfer molding (VARTM) that impedes their high-performance applications such as in aerospace, automobile, marine and building industries. The present research included fabrication of 3DP fiberglass-reinforced nylon composites, with maximum possible fiber content dictated by the current 3D printing technology at varying fiber orientations (such as 0/0, 0/90, ±45 and 0/45/90/−45) and characterizing their microstructural and performance properties, such as tensile and impact resistance (Drop-weight, Izod and Charpy). Results indicated that fiber orientation with maximum fiber content have tremendous effect on the improvement of the performance of the 3DP composites, even though they inherently contain structural defects in terms of voids resulting in premature failure of the composites. Benchmarking the results with VARTM 3D orthogonal woven (3DOW) composites revealed that 3DP composites had slightly lower tensile strength due to poor matrix infusion and voids between adjacent fiber layers/raster, and delamination due to lack of through-thickness reinforcement, but excellent impact strength (224% more strong) due to favorable effect of structural voids and having a laminated structure developed in layer-by-layer fashion.

Advanced textile technology for fabrication of ramie fiber PLA composites with enhanced mechanical properties

Poly (lactic acid) (PLA) has been widely used in preparation of biomass composites in recent years. Ramie fiber (RFs) can be introduced as a reinforcing element to enhance the performance of PLA composites. In this study, a novel fabrication technology through the combination of two-dimensional (2D) braiding and three-dimensional (3D) weaving are used for the preparation of RF/PLA composites with optimized mechanical properties. The twist ratio of ply/single yarn, the curing parameters, and RF content are considered to optimize the mechanical properties of the 3D orthogonal woven composites (3D composites). The tensile strength of RF ply yarn composites increases firstly and then decreases with the increase of twist ratio, and reach the maximum tensile strength (60.4 MPa) when the twist ratio is 0.3. The flexural and shearing properties of the 3D RF/PLA composites reach maximum under optimal curing conditions (190 ℃, 5 MPa, 30 min) at 50% RF content. The maximum flexural strength and modulus are higher than those reported for short RF composites and RF fabric composites. The high performance and low-cost 3D RF/PLA composites have good application potential in the automobile manufacturing industry.

Tensile properties of 3D printed continuous fiberglass reinforced cellular composites

Recent advancements in 3D printing involve reinforcing the polymer matrix with high-strength fibers offer improved mechanical properties over unreinforced polymeric materials. The fiber-reinforcement offers a great potential to customize fiber-reinforced 3D printed polymer composites for complex shapes and high-performance parts for diverse end use applications. The advance capabilities also allow to vary the 3D printed composite weight without compromising the mechanical properties. The aim of this research was to investigate unique macrostructures of 3D printed samples developed by varying the printing parameters, and their influence on the tensile behavior. Samples developed for this study comprised of nylon matrix reinforced with continuous fiberglass with three varying fiber orientations and four different infill geometries. Tensile properties of the unreinforced and reinforced 3D printed samples were evaluated to investigate the impact of fiber orientation and infill geometries and further benchmarked with traditional 3D orthogonal woven (3DOW) composites. The results indicated that the tensile properties due to fiber orientation mainly dictated the tensile properties more than the cellular structure. The analyses from this study showed that the macrostructure (hence tensile properties) of 3D printed specimens were directly related to the printing parameters that include fiber amount and orientation, void formation and the bonding between individual raster/layers.

Finite element analysis of hybrid 3D orthogonal woven composite subjected to ballistic impact with multi‐scale modeling

The present study deals with the finite element analysis (FEA) of hybrid 3D orthogonal woven composite (3DOWC) subjected to ballistic impact by a conical‐cylindrical projectile. The present simulation incorporates the micro‐meso‐macro transition approach is used for developing the intricate design of the target plate. The glass fibers are used for Warp and Weft direction, and Kevlar fibers are considered for the z‐direction binder yarns. The model is approved by utilizing 2D weave design, which has been examined by impacting the conical‐cylindrical projectile and compared with the available literature. Furthermore, the ballistic analysis is extended for the Hybrid 3DOWC, where the effect of residual velocity and energy absorptions are studied. The study highlights that z‐direction fibers have not much influence on energy absorption for both the hybrid and unhybridized 3DOWC. Furthermore, the influence of hybridization will subside with the increased velocities.

Multiscale Modelling of 3D Orthogonal Woven Composite under Ballistic Impact Using FEM

The present paper deals with the multi-scale modelling and finite element analysis of Kevlar/Epoxy 3D Orthogonal woven composite (3DOWC) subjected to ballistic impact by a conical-cylindrical steel projectile. These are designed by utilising a Micro-Meso-Macro transition approach called Macro Homogeneous-Meso heterogeneous modelling technique. The Micro-Meso-Macro transition approach has been implemented in this research to develop the complex weave architecture of the target plate, and, a voxel-based non-conformal mesh has been used to understand the behaviour of Representative Volume Element (RVE). The model is validated by using 2D weave architecture which has been analysed for conical 90 ° projectile made up of 7.62 calibre. The damage properties are implemented using a user-defined function in the explicit analysis VUMAT. The Macro homogeneous results provide the velocity variation and energy absorption of the projectile with respect to the time history. Also, the energy absorption by its constituents are presented here, and substantial validation of results have been observed with the available literature.

Comparisons of tension–tension fatigue behavior between the 3D orthogonal woven and biaxial warp-knitted composites

In this article, the tensile fatigue properties of 3D orthogonal woven composites (3DOWCs) and biaxial warp knitted composites in 0°, 30°, 45°and 90° directions were studied and compared experimentally. The quasi-static tensile test and tension–tension fatigue test were carried out to obtain the stress–strain curves, the S–N curves and stiffness degradation curves. The results indicate that the two types of composites both exhibit greater stress in 0° and 90° directions and greater strain in 30° and 45° directions. The S–N curves obtained by experimental fitting can better reflect the fatigue degree of the two composites. The stiffness degradation rate of 3DOWCs is much higher than that of biaxial warp-knitted composites except in the 90° direction. The aim of this study is to provide a theoretical study for two kinds of composites to ensure the longest service life in practical applications.

Influence of asymmetric hybridization on impact response of 3D orthogonal woven composites

The mechanical and failure behavior under high velocity impact of asymmetric hybrid three-dimensional orthogonal woven composite (3DWC) were investigated through experiments and finite element modeling. Two types of non-hybrid and one asymmetric hybrid 3DWCs panels were manufactured with the combination of carbon and Kevlar fiber tows and tested under different impact energies. The hybrid panels were impacted on both faces separately to analyze the directional behavior under impact loading. The energy absorption capability of the hybrid material is sufficiently increased when impacted on carbon face due to diversified failure behavior of carbon and Kevlar layers. Damage in Kevlar layers was due to fiber rupture and pull-out while in carbon layers, damage was induced by matrix cracking and brittle fiber failure. The impact response is simulated through continuum shell based finite element model using connector element technique. The proposed methodology gives a fair comparison with the experimental data in terms of failure behavior of the hybrid material during the impact process.

Thermo-mechanical modeling of C/C 3D orthogonal and angle interlock woven fabric composites in high temperature environment

Carbon/Carbon (C/C) 3D textile composites are very popular in various fields of applications such as aerospace, defence, and chemical industries due to their attractive mechanical and thermal properties. Consequently, investigation of these properties of 3D C/C textile composites has become an essential primary requirement for thermo-structural analysis of composites structures in high-temperature applications. In this study, a finite element based Representative Volume Element (RVE) has been developed to perform the thermo-mechanical analysis. Thermo-mechanical properties of 3D C/C orthogonal interlock woven fabric composite (OIWFC) and angle interlock woven fabric composite (AIWFC) are investigated. The RVE analysis for the evaluation of thermo-mechanical properties has been carried out with the implementation of multi-scale modeling techniques and periodic boundary conditions (BCs). The micro-scale analysis predicts the thermo-mechanical properties of fiber yarn/tow. Further, yarn properties are incorporated into the meso-scale model to predict the thermo-mechanical properties of 3D C/C woven fabric composites. The variation of mechanical constants and coefficient of thermal expansions (CTEs) values have been investigated within the temperature range from 300 K to 2500 K. It has been extended for the prediction of variation of thermo-mechanical properties with respect to the number of weft layers along the thickness direction of the 3D orthogonal interlock woven fabric composites. The validation study has been carried out and present FE based numerical results agree well with numerical and experimental results from the available literature.

A Comprehensive Study on the Mechanical Properties of Different 3D Woven Carbon Fiber-Epoxy Composites.

In this work, the tensile, compressive, and flexural properties of three types of 3D woven composites were studied in three directions. To make an accurate comparison, three 3D woven composites are made to have the same fiber volume content by controlling the weaving parameters of 3D fabric. The results show that the 3D orthogonal woven composite (3DOWC) has better overall mechanical properties than those of the 3D shallow straight-joint woven composite (3DSSWC) and 3D shallow bend-joint woven composite (3DSBWC) in the warp direction, including tension, compression, and flexural strength. Interestingly their mechanical properties in the weft direction are about the same. In the through-thickness direction, however, the tensile and flexural strength of 3DOWC is about the same as 3DSBW, both higher than that of 3DSSWC. The compressive strength, on the other hand, is mainly dependent on the number of weft yarns in the through-thickness direction.

The temperature effect on the inter-laminar shear properties and failure mechanism of 3D orthogonal woven composites

Recent increases in the use of carbon fiber reinforced plastics, especially for high-temperature applications, has induced new challenges in evaluating their mechanical properties. The effects of temperature on the shear performance of 3-dimensional orthogonal and 2-dimensional plain woven composites were compared in this study through double-notch shear tests. A scanning electron microscope was employed to investigate the fiber/matrix interface properties to reveal the failure characteristics. The results showed that temperature had a visible impact on the inter-laminar shear strength (ILSS), deformation modes, and failure mechanism. The ILSS decreased as temperature increased, which was caused by the degradation of the matrix properties and fiber/matrix interface properties at high temperature. A finite element model was established to analyze the transient deformation process and the damage mechanism of the 3D orthogonal woven composite. This indicated that Z-binder yarns could improve the delamination resistance of 3D orthogonal woven composites, especially under high temperatures. The changes in failure modes of the 3D orthogonal woven composites was put down to thermal softening of the epoxy resin caused by high temperature and the undulation of the yarns.

Automated generation of 3D orthogonal woven composites RVEs including yarn cross-section variations

This contribution presents an approach to generate unit-cell models of 3D orthogonal woven non-crimp fabric composites with the ability to incorporate cross-section variations in the weft and binder yarns. The approach starts from an initial loose-state configuration of the fiber-bundles, in which each fiber-bundle is represented by a single discretised line. The discretised lines are shaped in a step-wise generation process by geometrical operations. During the generation procedure, the surface weft yarns and the binder yarns are transformed into a boundary- or inner-line configuration, respectively, to account for their cross-section variation in subsequent steps. The fiber volume fraction and fiber direction to be used subsequently in simulations are modelled on cross-sections in a post-processing step. The shape of the surface weft yarn cross-section and binder yarn cross-sections and centerline for different binder contents, diameter and tensioning can be automatically accounted for. The geometrical models are then transformed into finite element models by an automated meshing procedure to investigate how the binder yarn, and cross-section variations in the surface weft and binder yarns alter the stiffness and damage initiation levels

A unified framework for the multi-scale computational homogenisation of 3D-textile composites

This paper extends the applications of a novel and fully automated multi-scale computational homogenisation framework, originally proposed by the authors (Ullah et al. (2017)) for unidirectional and 2D-textile composites, to 3D-textile composites. 3D-textile composites offer many advantages over 2D-textile composites but their highly complicated and unpredictable post-cured geometries make their design very challenging. Accurate computational models are therefore essential to the development of these materials. The computational framework described in this paper possesses a variety of novel features which have never been tried for this class of composites and can potentially help to fully automatise and improve their design process. A unified approach is used to impose the representative volume element boundary conditions, which allows convenient switching between linear displacement, uniform traction and periodic boundary conditions. The computational framework is implemented using hierarchic basis functions of arbitrary polynomial order, which allows one to increase the order of approximation without changing the finite element mesh. The yarns' principal directions, required for the transversely isotropic material model are calculated using a potential flow analysis along these yarns. This feature is very useful for 3D-textile composites and can accurately determine fibres’ directions even in the case of very deformed yarns. A numerical example from literature consisting of a 3D-orthogonal woven composite is used to demonstrate the correct implementation and performance of the developed computational framework. Also, the developed computational framework is used to perform a comparative study of the homogenised mechanical properties of five 3D-textile composites with different yarn architectures.

Progressive damage modelling and experimental investigation of three-dimensional orthogonal woven composites with tilted binder

This paper investigates the tensile properties of 3D orthogonal woven carbon fiber composites with tilted binder by experiment and simulation. The tensile failure strain and fracture mode of this composite show distinguished discrepancy with idealized 3D orthogonal woven composites experimentally. In order to explain this specific failure mechanism, a unit cell finite element model incorporated with damage models of constituents is established to reproduce the damage initiation and propagation of 3D orthogonal woven composites with tilted binder during tensile test. A three-dimensional failure criterion based on Hashin's criterion and Pinho's criterion is utilized to describe the progressive damage of yarns, while the non-linear behavior of the matrix is predicted by Drucker-Prager yield criterion. Besides, a traction-separation law is applied to predict the damage of yarn-matrix interface. The proposed unit cell model is correlated and validated by global stress–strain curves, DIC full-field strain distributions and modulus history curve. The damage evolution process of 3D orthogonal woven carbon fiber composites with tilted binder, including fiber tow failure, matrix cracking, and interfacial debonding, is recorded and investigated by the modulus history curve from simulation.

A Comparative Study on Interlaminar Properties of L-shaped Two-Dimensional (2D) and Three-Dimensional (3D) Woven Composites

The effect of fiber-resin interfacial structures (especially three-dimensional (3D) structures) on the delamination resistance of L-shaped beam composites was investigated via hinged loading tensile tests. Four types of structures were woven, and the corresponding reinforced epoxy composites were manufactured through a vacuum-assisted resin infusion (VARI) process. The results revealed that the two-dimensional (2D) laminate and 3D shallow-straight woven composite (3DSSWC) had the similar interlaminar strength and failed via delamination. However, compared with the resistance of these composites, a significantly higher delamination resistance was realized for a 3D orthogonal woven composite (3DOWC) and a 3D shallow-bend woven composite (3DSBWC). This high resistance resulted from the reinforcing fibers (i.e., Z-yarns) in the Z-direction and the considerable yarn waviness of the 3DOWC and the 3DSBWC, respectively. The failure mode of 3DOWC was characterized by interlayer delamination and Z-yarn or weft yarn breakage. Moreover, the failure mode of 3DSBWC was dominated by delamination and weft yarn breakage. Therefore, the 3D orthogonal (3DOW) and 3D shallow-bend (3DSBW) woven structures were quite effective in resisting delamination and, of the structures considered, the 3DSBW structure yielded the best L-shaped beam composite.

The Effect of the Structural Parameters of 3D Orthogonal Woven Composites on their Impact Responses under Different Modes of Impact

Development of three-dimensional (3D) weaving technology introduced new and enhanced features to the 2D weaving technology. 3D Orthogonal Woven (3DOW) preforms have a through-thickness yarn component that significantly enhances the impact resistance and delamination resistance. In this study, a range of 3DOW E-glass preforms were woven using 3D weaving technology and then converted into composites, using vacuum assisted resin transfer molding technology. The composite samples had varying structural parameters, such as, number of Y-yarn layers, X-yarn pick density, Z-yarn interlacing pattern. The purpose was to study the effect of changing those structural parameters on the different impact responses of the 3DOW composites under different modes of impact, namely, tup, Izod and Charpy impact. The study indicated that, the number of Y-yarn layers, had the most significant effect on the total tup, Izod, and Charpy impact energies. The X-yarn pick density, had slight effect on the three modes of impact, while the Z-yarn weave design only had a slight significant effect on the tup and Charpy impact energy.

Effect of Z-binder tension and internal micro-structure on damage behavior of 3D orthogonal woven composite

The main goal of this study was to investigate the effect of tow tension and related internal micro-structure on the damage behavior of 3D orthogonal woven composites under tensile loading. For representing the internal micro-structure of the composite with respect to varying tow cross-section and the unregulated undulated path which are introduced by Z-binder tension, a dynamical method at filament level which simulates an interlacing process was used to obtain the fabric architecture. Then, an element recognition algorithm was proposed to convert a representative unit cell of 3D woven fabric architectures into a finite element model with 8-node solid elements consisting of four kinds of sets in terms of warp, weft, Z-binder tows and resin matrix. In addition, filament trajectory was also extracted from fabric architecture to serve as a local material orientation. Comparative simulations under tensile loading were conducted on the FEA models generated by this work and texgen software, respectively. An experiment was also carried out to verify the simulation results. The stress–strain curve in the proposed model was found to be closer to the experiment data. The results show that the tensile modulus and strength reduce due to the diverged warp tow path which is induced by the interaction between the tows during the weaving process. Moreover, the irregularity and compressed weft tow cross-sections nearby the intercross point are more likely to generate the transverse damage which would result in the non-linear tensile behavior of the composite material.

Numerical Analysis of Macro-Scale Mechanical Behaviors of 3D Orthogonal Woven Composites using a Voxel-Based Finite Element Model

A study is conducted with the aim of developing voxel-based finite element method related to the whole fiber distribution for predicting the macro-mechanical properties of 3D orthogonal woven composites. For the rationality of this model, multi-scale finite element method, which is on the basis of the surface and interior representative volume cells, and digital image correlation tests are carried out. The results show that the proposed voxel-based finite element method is capable of precisely calculating the macro-level properties of 3D orthogonal woven composites, validated by the comparison the mechanical behaviors as well as the full-field strain fields.