Three-dimensional Woven Composites Research Articles

Predicting the low-velocity impact failure of 3D woven composites based on a local homogenization modeling strategy

Three-dimensional woven composites (3DWC) have emerged as a promising lightweight solution for aviation structures prone to impact loads during operational life. However, effectively simulating the impact response and failure process of 3DWC presents a challenging task, requiring a delicate balance between computational efficiency and accuracy. In this study, a local-homogenization-based finite element modeling strategy for simulating the impact behavior of 3DWC panels was proposed. The model is constructed based on the fabric's architectural design, involving the decomposition of the unit cell into multiple homogeneous subcell elements aligned with the local yarn direction. The calibration exercises are conducted by simulating the mechanical responses of 3DWC under various monotonic loads and comparing the results with experimental data. Subsequently, the model is applied to predict the response of a 3DWC panel to low-velocity impacts, further corroborating the predictions through experimental validation. The modeling strategy proposed in this study provides an efficient method for analyzing and designing 3DWC structures.

Research on the Influence of Yarn Reduction on the Bending Performance of Three-dimensional Woven Composites

Research on the Influence of Yarn Reduction on the Bending Performance of Three-dimensional Woven Composites

Damage failure analysis of flexible-oriented three-dimensional woven composites with void defects: An experimental and numerical study

Three-dimensional woven structures have garnered significant interest due to their enhanced mechanical properties and structural integrity. This study delves into a detailed analysis of progressive damage failure in multi-structured, flexible-oriented three-dimensional woven composites (FO3DWC), with a specific focus on the effects of voids. Employing the flexible-oriented three-dimensional woven process (FO3DWP), four distinct structures were fabricated and subjected to uniaxial tensile tests. The study integrates an progressive damage failure model coupled with a random element selection method to investigate the effects of void defects on mechanical properties. The results show that significant variations occur in the strength of the L45135 structure due to the void defects, with a maximum decrease of up to 4.37% when the porosity is 5%. This research provides a quantitative understanding of how voids impact the mechanical performance of FO3DWC, offering valuable guidance for material design and application in various engineering fields.

Multi-Scale Modeling and Analysis of Three-Dimensional Woven Composites Shell with Cut-Outs

Advancement in weaving techniques has made woven composites used in the diverse fields of aerospace, automobile, and many more. In the past few decades, textile composites have been considered the best materials, where most of the studies are focused on plain woven composites. The designing of these structures made up of plain-woven composites associated with discontinuities in the form of cut-outs may lead to the failure of the structure. The collapse in the structure will be due to stress concentration or popularly known as stress raisers. Therefore, this research proposes a numerical study based on finite element analysis (FEA) using a multi-scale modeling approach for a three-dimensional (3D) plain-woven composite 3D shell with varied cut-out shapes. The analysis is performed to comprehend the result of fiber orientation on the mechanical behavior of 3D woven composites having circular and elliptical cut-outs. This research proposes a ply stacking sequence that significantly reduces stress concentration primarily at interruptions in the structure. It is concluded that combining different ply layers having fiber orientation of [Formula: see text] in a multilayer composite 3D shell reduces stress concentration around the periphery of circular or elliptical cut-outs.

Free-edge effect on the tensile properties of 3D woven composites

Free-edge effect is one of the factors affecting the mechanical properties of three-dimensional woven composites under tensile load. However, current research is relatively poorly understood regarding the effect of free-edge on the stiffness and strength of the material. This paper aims at examining the influence of free-edge effect on the mechanical properties of 3D woven composites under tension through experimental and simulation methods. The three-dimensional digital image correlation (DIC) technique is used to collect the full-field strains on the specimen surface during the test, and the stress-strain differences in different regions in the width direction are analyzed, and the overlap of the curves in each region is found to be high, indicating that the boundary effect has a small influence on the tensile properties of 3D woven composites. Experimental studies are conducted on specimens of different widths (within the range of 15–20 mm), and the results indicate that the differences in mechanical properties of 3D woven composites under tension loading in this width range are not significant. A progressive damage finite element model is developed for calculation and compared with experimental results. It is found that the tensile properties of the material decreased when the width of the specimen is less than twice the size of the single cell. This study can provide certain data support for the study of the mechanical properties of 3D woven composites and enable the subsequent more in-depth study to provide a certain foundation.

A geometric modeling method for an integrally stiffened panel with three-dimensional woven composites

In this article, we propose a geometric modeling method for an integrally stiffened panel using 3D woven composites. To observe the geometric shapes of the panel, we design weave patterns in which the skin and stiffener are integrated and manufacture the panel. Cross-sections of the manufactured panel are observed using a microscope, and paths and shapes of tows are modeled using weaving parameters and the obtained cross-sections. To verify the method, buckling analysis is performed on the panel and compared with test results. The proposed method can be effectively applied to the design of integrally stiffened panel using 3D woven composites.

Progressive failure prediction of three-dimensional woven composites using a generic multi-scale analytical model

Three-dimensional (3D) woven composites with higher interlaminar fracture toughness, better damage tolerance and improved mechanical stability are being increasingly used in aviation and automotive industries. To expedite their analysis and design efficiency, developing simple and accurate modeling tools capable of quickly evaluating their mechanical properties and progressive failure is necessary. In this paper, a generic multi-scale analytical model for mechanical response prediction and failure behavior characterization of 3D woven composites is presented and validated by using the existing experimental and numerical results. Subsequently, the analytical model is adopted to evaluate the predictive capability of different unit cell model schemes and to investigate the effects of geometric parameters on stiffness and strength properties of composites. The results indicate that the interior-surface integrated cell model scheme has the overall best performance in mechanical response prediction of composites. In addition, an exponential model and a linear model are proposed to quantify the relationships between the number of weft layer and yarn density and mechanical properties, respectively. The present results demonstrate the analytical model can be a useful tool to provide an insight for the analysis and design of other 3D woven composites.

Prediction of mechanical properties for three-dimensional woven composites considering interference between tows

The mechanical performance of three-dimensional woven composites is usually modeled by an ideal model with straight tow paths and constant cross-sectional areas. This ideal model predicts inaccurate properties due to oversimplification of tow shapes. In this paper, we present a more accurate method to predict properties of the 3D woven composite considering waviness and contraction of tows due to interference between them. The tow waviness is defined by elliptic and trigonometric functions. The shrinkage of the tow cross-sectional area is modeled using a cubic polynomial. The elastic moduli are predicted using the modeled tows and the weighted average model. The predicted properties are compared with test results to verify the accuracy. In addition, the usefulness of the present method is verified by comparing the calculated moduli using the ideal model. We conclude that the present method is useful for the design of structures to which 3D woven composites are applied.

Impact Performance of Three-dimensional Woven Composites with Novel Binding Yarn Patterns

ABSTRACT This research offered an experimental examination of the effect of binder yarns, and 3D woven patterns on impact (Charpy and drop weight impact), and compression after impact (CAI) performance of seven (07) different kinds of 3D woven jute/green epoxy composites. Along with four (04) typical classifications of 3D woven reinforcements i.e., OLL, OTT, ALL, ATT, and three (03) novel (hybrid) 3D reinforcements i.e., H1 (OTT and ATT interlocking pattern), H2 (OTT and ALL interlocking pattern), H3 (OLL warp and weft interlocks “bidirectional”) were also developed on dobby weaving machine. OTT composite displayed the highest amount of impact strength during Charpy impact in both in-plane directions i.e., warp and weft in comparison with others due to the existence of the truly vertical binder yarns which is comparable with H1. While ALL sample exhibited the highest value of maximum load, work done, and energy absorbed during the 3 J and 6 J drop weight impact energies which is nearest comparable with hybrid 3 (H3) composite. H3 composite sample revealed the highest value of compression after impact (CAI) stress and modulus in both energy levels due to the presence of both warp and weft binder yarns in a single 3D structure.

Axial-compression performance and finite element analysis of special-shaped tubular three-dimensional woven composites with different thicknesses and shapes

In this research, the self-reinforced structures tube preforms, which are the special-shaped tubular three-dimensional woven preforms, had been manufactured on semi-automatic looms. To prepare special-shaped tubular three-dimensional woven composites with different wall thicknesses and shapes, the vacuum-assisted resin transfer method was used by performing the prepared preform and resin as the reinforcement and matrix. Then, the axial compression performance was tested on a universal material testing machine. The results revealed that both the wall thicknesses and the shape had remarkable effects on the composites’ axial-compression properties. The performance of special-shaped tubular three-dimensional woven composites and normal tubular three-dimensional woven composites were compared and special-shaped tubular three-dimensional woven composites were better. Finally, finite element analysis was adopted in this research. The initial damage, stress evolution, and final failure of special-shaped tubular three-dimensional woven composites had been shown by the analysis. The stress concentration and failure mechanism of the composite materials after axial compression was revealed and the finite element model was correct and can predict the mechanical properties of special-shaped tubular three-dimensional woven composites.

Elastic and fracture behavior of three-dimensional ply-to-ply angle interlock woven composites: Through-thickness, size effect, and multiaxial tests

This work presents a comprehensive investigation of the elastic and fracture behavior of ply-to-ply angle interlock three-dimensional woven composites. The research investigated novel splitting and wedge-driven out-of-plane fracture tests to shed light on the tensile fracture behavior in the thickness direction and to provide estimates of the out-of-plane tensile strength and fracture energy. In addition, size effect tests on geometrically-scaled Single Edge Notch Tension (SENT) specimens were performed to fully characterize the intra-laminar fracture energy of the material and to study the scaling of structural strength in this type of three-dimensional composites. The results confirmed that size effect in the structural strength of these materials is significant. In fact, even if the range of sizes investigated was broader than in any previous size effect study on traditional laminated composites and two-dimensional textile composites, all the experimental data fell in the transition zone between quasi-ductile and brittle behavior. This implies strong damage tolerance of the investigated three-dimensional composites. The analysis of the data via Bažant’s Type II Size Effect Law (SEL) enabled the objective characterization of the intra-laminar fracture energy of three-dimensional composites for the first time. Finally, Arcan rig tests combined with X-ray micro-computed tomography allowed unprecedented insights on the different damage mechanisms under multi-axial nominal loading conditions, particularly tension-dominated and shear-dominated conditions.

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

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.

A progressive damage model for three-dimensional woven composites under ballistic impact loading

Ballistic impact damage of three-dimensional woven composites have not been sufficiently studied. Numerical and experimental methods were used to evaluate the ballistic penetration behavior of three dimensional woven carbon fiber reinforced composites in this paper. A one-stage light gas gun apparatus was employed to conduct impact tests. Based on the nonhomogeneous elements method, a finite element model considering the strain rate effect of the matrix was established to analyze the damage mechanisms of 3D woven composites subjected to ballistic impact loading. The speed history and acceleration history of the projectile were obtained during the impact, as well as the damage process of fiber yarns and the matrix. The simulation results showing good agreement with experimental observations, in terms of damage patterns, residual velocities and damage morphology. The results show that the finite element model in this paper is reasonable for ballistic performance design of 3D woven composites.

Can a three-dimensional composite really provide better mechanical performance compared to two-dimensional composite under compressive loading?

A series of split Hopkinson pressure bar tests on two-dimensional and three-dimensional woven composites were presented in order to obtain a reliable comparison between the two types of composites and the effect of the z-yarns along the third direction. These tests were done along different configurations: in-plane and out-of-plane compression test. For the three-dimensional woven composite, two different configurations were studied: compression responses along to the stitched direction and orthogonal to the stitched direction. It was found that three-dimensional woven composites exhibit an increase in strength for both: in-plane and out-of-plane tests.

Impact damage and compression behaviours of three-dimensional angle-interlock woven composites after thermo-oxidation degradation

This paper reports impact and compression behaviours of three-dimensional angle interlock woven composites after the thermal ageing degradation in both experimental and finite element analyses. The composite coupons have been aged in atmospheric environment for 4, 8, 16 and 32 days at 180℃. Barely visible impact damage was induced by low velocity impact test and the residual strength was evaluated by following compression test. The results show a substantial decline in compression after impact properties after thermal ageing. After aging at 180℃ for 32 days, the compression after impact stress and modulus retention rates of three-dimensional woven composites are 59% and 82.2%, respectively. Such degradation is attributed to interface damage and matrix degradation. The fracture morphologies observed by microscopy revealed that the failure of the original specimen was dominated by matrix crack, while for long time aged specimens interface degradation became main damage mechanism. The numerical study was used to unveil the influence of matrix crack and interface degradation on failure developments of composites. The results indicate a variation from a brittle failure mode to a progressive failure model after long time ageing.

Multi-Scale Finite Element Analyses of Thermal Conductivities of Three Dimensional Woven Composites

This paper summarizes an extensive experimental and prediction study of thermal conductivities of three-dimensional woven composites (3DWCs). Three kinds of innovative 3D woven architectures are examined, including 2.5D angle-interlock, 2.5D angle-interlock (with warp reinforcement), and 3D orthogonal woven architectures. The differences of thermal behaviors of 3DWCs in plane and out of plane are assessed by using multi-scale finite element analysis. For the validation of models, the thickness direction thermal conductivity of 3DWCs are measured. It is indicated that the predicted results are in good agreement with the experimental results. The effects of weave density and fabric architecture on the distribution of heat flux and temperature have been discussed in this work, which determined the thermal conductivities of 3DWCs. From this study, it can be expected that the need of thermal performance of 3DWCs can obtained according to optimize the weave parameters based on the high designability of 3DWCs.

Influence of fabric architecture and weaving parameter on the thermal conductivities of 3D woven composites

To investigate the effect of fabric architectures and weaving parameters on thermal conductivities of three-dimensional woven composites, the 2.5D angle-interlock woven composites, 2.5D angle-interlock (with warp reinforcement) woven composites, and 3D orthogonal woven composites were prepared. The thermal conductivities of these woven composites were measured by using transient hot-wire method in this study. It was indicated that the thermal conductivities of three-dimensional woven composites showed significant differences due to the distribution of continuous fibers in three-dimensional woven composites with different structures, which could influence the sum fiber content on the cross section of heat flow. More importantly, compared with 2.5D angle-interlock woven composites and 2.5D angle-interlock (with warp reinforcement) woven composites, 3D orthogonal woven composites exhibited better performance in thermal conductivity. Overall, it was concluded that the thermal conductivities of three-dimensional woven composites were influenced by the fabric architectures and weaving parameters, such as the volume fraction, density, and types of fibers. Furthermore, the volume fraction of fibers on the cross section of heat flow was the dominant factor for thermal conductivities of different woven composites.

Multi-scale analysis and optimisation of three-dimensional woven composite structures combining response surface method and genetic algorithms

The paper proposes an optimisation strategy for the design of structures made of three-dimensional woven composites. The knowledge of the weaving architecture is essential to properly optimise the design of the structural components subjected to specific load conditions. Owing to the hierarchy and periodicity of the textile composite materials, a multi-scale parameterisation modelling strategy combining the adoption of a representative volume element and periodic boundary conditions is employed to estimate the behaviour of stiffened panels. In order to minimise the expensive computational cost, response surface method techniques are used to generate the approximated structural responses in an efficient and applicable way. The approach here proposed consists of a multi-scale parameterization analysis strategy and an optimisation framework based on the response surface technique and genetic algorithms. The optimal design results are verified by finite element analysis proving that the response surface method integrated with genetic algorithms allows to easily investigate the influence of the fabrics constitutive parameters on the structural behaviour.

Comparative study of mechanical properties and damage kinetics of two- and three-dimensional woven composites under high-strain rate dynamic compressive loading

The in-plane compressive behavior of two- and three-dimensional woven composite was investigated at high strain rates. The Split Hopkinson Pressure Bar is employed to test the high strain rate dynamic mechanical properties of E-glass vinylester composite material. For three-dimensional woven composite, two configurations were tested: compression responses along the stitched direction and orthogonal to the stitched direction. Dynamic compression properties for two- and three-dimensional are determined and compared. Experimental results show that the strain rate has a significant effect on the two- and three-dimensional woven composite response. It is observed that the three-dimensional woven composite has higher compression strength and dynamic modulus than the two-dimensional composite at high strain rate. For this study, a high-speed camera was used to determine the damage kinetics under dynamic load. The two-dimensional woven composite is mainly damaged in a mode of matrix cracks and severe delamination, while the mode for three-dimensional woven composite is mainly cracking of matrix and delamination for in-plane along to the stitched direction and shear banding failure for in-plane orthogonal to the stitched direction.

Progressive failure analysis of three-dimensional woven carbon composites in single-bolt, double-shear bearing

A three-dimensional progressive damage model has been developed to capture the onset and initial propagation of damage within a three-dimensional woven composite in a single-bolt, double-shear joint. Reinforced with a three-dimensional woven ply to ply interlock IM7 carbon fiber preform impregnated with toughened epoxy resin and manufactured using a resin transfer molding process, the composite represents a unique material currently used in select aerospace structures. The modeled joint is commonly found in many aerospace structures and, when combined with the progressive damage response of this three-dimensional woven composite, the material response can be reliably predicted with a three-dimensional non-linear finite element model. This model is constructed using an orthotropic material assumption far from the bearing area and a voxelized mesoscale model with an as-molded geometry representing matrix and impregnated tow phases. The well-established Hashin failure criteria and the Matzenmiller–Lubliner–Taylor damage model were implemented with the unique morphology of three-dimensional woven composites. The onset of damage and trends seen in the model were found to be in agreement with previous experimental findings.