Three-dimensional Orthogonal Woven Composites Research Articles

Numerical investigation of the low-velocity impact response of 3D orthogonal woven composite plates with preloads

Three-dimensional orthogonal woven composites (3DOWCs) offer significant advantages in engineering applications due to their designability for spatial structures and ability to minimize delamination damage. As primary load-bearing structures, 3DOWCs are always in preloading conditions prior to potential low-velocity impact (LVI) events. This paper presents a macro-meso coupled finite element (FE) model for investigating the response of preloaded 3DOWCs subjected to LVI. The accuracy of the proposed numerical model is validated by a comparison with available experimental data in terms of impact performance and damage state. Furthermore, the influence of preload and impactor shape on the LVI performance of 3DOWCs is examined, and detailed analysis is provided regarding the associated damage mechanisms. This study offers a transferable numerical approach that can be applied to studying the coupling problems of LVI and preload in other textile composite structures.

Evaluation of multi-directional compression behaviors and failure of three-dimensional orthogonal woven composites via liquid nitrogen temperature

Three-dimensional orthogonal woven composites (3DOWCs) are extensively employed in structural engineering applications for their lightweight, high designability, and excellent interlayer performances. This work constructed two 3DOWCs with different fiber volume contents, and their multi-directional compression properties and damage mechanisms at room and liquid nitrogen temperatures (RT and LNT) were thoroughly investigated and evaluated. Temperatures, fiber volume contents, and loading directions all had a significant influence on behaviors. The stress-strain curves presented ductility at RT and gradually decreased after reaching the maximum load, whereas they were brittle and rapidly decreased at LNT. Compared to the compression properties at RT, the compression strength of 3DOWC40-LNT and 3DOWC50-LNT increased by 22.6% and 9.3% in the warp direction, 11.8% and 29.0% in the weft direction, as well as 32.9% and 24.6% in the Z direction. Additionally, edge yarn stripping and shear cracking were the primary fracture patterns for 3DOWCs under RT, while they exhibited interface layering, yarn fracture, shear cracking, and interfacial debonding at LNT, especially the deformation along the warp direction was more pronounced under Z direction compression.

Multiscale damage modelling of notched and un-notched 3D woven composites with randomly distributed manufacturing defects

This work proposes a stochastic multiscale computational framework for damage modelling in 3D woven composite laminates, by considering the random distribution of manufacturing-induced imperfections. The proposed method is demonstrated to be accurate, while being simple to implement and requiring modest computational resources. In this approach, a limited number of cross-sectional views obtained from micro-computed tomography (µCT) are used to obtain the stochastic distribution of two key manufacturing-induced defects, namely waviness and voids. This distribution is fed into a multiscale progressive damage model to predict the damage response of three-dimensional (3D) orthogonal woven composites. The accuracy of the proposed model was demonstrated by performing a series of finite element simulations of the un-notched and notched tensile tests (having two different hole sizes) for resin-infused thermoplastic (Elium®) 3D woven composites. Excellent correlation was achieved between experiments and the stochastic finite element simulations. This demonstrates the effectiveness of the proposed stochastic multiscale model. The model successfully captured the stochastic nature of tensile responses (ultimate tensile strength and stiffness), damage modes (matrix damage and fibre failure), and initiation and propagation of transverse cracks in thermoplastic 3D woven composites, consistent with experimental observation. The stochastic computational framework presented in this paper can be used to guide the design and optimization of 3D textile composite structures.

Development and experimental verification of a modified constitutive model for 3D orthogonal woven composite under bird impact

Three-dimensional (3D) orthogonal woven composites have potential application as a material for aeroengine blades, which are required to withstand the impact of a bird strike. In the current research, quasi-static and dynamic tensile tests were conducted on a 3D orthogonal woven composite in the warp and weft directions. The results indicate that the ultimate strength increased while the failure strain decreased with an increase of the strain rate. The effects of strain rate on the ultimate strength in the warp and weft directions are different. Therefore, a modified constitutive model that accounts for the different effects of the strain rate in different directions was established. The corresponding parameters were obtained from the test results. Bird impact tests and numerical simulations using the developed constitutive model were carried out with 3D orthogonal woven composite panels. These panels resisted the impact of high-speed bird strikes through an overall deformation. As the impact speed increased, the maximum deformation of the target panel in the thickness direction increased and the residual deformation after the impact also increased significantly. The simulation results are in good agreement with the test results, demonstrating the effectiveness of the modified model.

Multi-directional compression behaviors and failure mechanisms of 3D orthogonal woven composites: Parametric modeling and strength prediction

Three-dimensional orthogonal woven composites (3DOWCs) are extensively adopted in various civil and military fields. Parametric finite element models of 3DOWCs were established based on the mesoscale method to predict the compression strength and progressive damage process. The effects of structural parameters and loading directions on the failure mechanisms were investigated. The predicted results agreed well with the experimental data. The results revealed that yarn densities and loading directions significantly influenced the compression strength. It increased as yarn densities increased, and the weft compression strength was almost the largest in all directions and reached the maximum value of 634.8 MPa. In this case, it was 16.9% and 166.9% higher than that of the warp and Z-directions. Damage evolutions demonstrated that the damage of yarns and matrix occurred separately at the intersection of yarns and yarns, and yarns and matrix. The damage patterns of small warp and large weft yarn densities composites included yarn buckling, the interfacial debonding between yarns and matrix, and matrix cracking. Yarn kinking and fracture were the two main damage patterns of large warp and small weft yarn densities composites, while composites with large warp and large weft yarn densities were more prone to matrix cracking.

Effect of the micro-structure on the compressive failure behavior of three-dimensional orthogonal woven composites

The failure behavior of three-dimensional orthogonal woven composites (3DOWCs) under in-plane axial compression has been experimentally and numerically investigated. The micro-structure at the intersecting points of the fabric reinforcement, which is induced by the tow force in the weaving process, is introduced. The strength and the induced damage along the warp and weft directions were investigated. The micro-structure of the 3DOWC including the details of the tow waviness and resin distribution was accurately obtained through a multiscale modeling approach. Resin cracking and the local stress concentration were captured by the numerical models, and they showed good correlations with the experimental results. The fiber undulation in the region of the tow intersection concentrated stress, which led to fiber fracture in the compression process. The main load-carrying tow, namely, the warp and weft tow along each direction, had different forms of undulation, which should be the reason for the decreasing compression-carrying capacity of the 3DOWC. With increasing Z-binder tow force, the level of fiber straightness decreased and the failure mode transformed from macroscopic brooming type to fiber microbucking. The inclination angle of the through-thickness fracture path suggested that fracture was induced by the shear failure in the load-carrying tows.

Experimental and numerical investigation of the behavior of three-dimensional orthogonal woven composite plates under high-velocity impact

The performance of the three-dimensional orthogonal woven composites (3DOWC) under high-velocity impact is studied in a combined experimental and numerical way. The experimental impact velocity ranges from 155 to 1499 m/s. The impact processes are also simulated with mesoscopic point model and the material point method (MPM). The experimental and numerical results agree well in both the residual velocity and the configuration. Four failure patterns are observed for the perforated specimens. An empirical formula is constructed based on the experimental and numerical results.

Reliability-based design optimization of 3D orthogonal woven composite automobile shock tower

Three-dimensional orthogonal woven composites are noted for their excellent mechanical properties and delamination resistance, so they are expected to have promising prospects in lightweight applications in the automobile industry. The multi-scale characteristics and inherent uncertainty of design variables pose great challenges to the optimization procedure for 3D orthogonal woven composite structures. This paper aims to propose a reliability-based design optimization method for guidance on the lightweight design of 3D orthogonal woven composite automobile shock tower, which includes design variables from material and structure. An analytical model was firstly set up to accurately predict the elastic and strength properties of composites. After that, a novel optimization procedure was established for the multi-scale reliability optimization design of composite shock tower, based on the combination of Monte Carlo reliability analysis method, Kriging surrogate model, and particle swarm optimization algorithm. According to the results, the optimized shock tower meets the requirements of structural performance and reliability, with a weight reduction of 37.83%.

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.

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.

Uncertainty quantification of mechanical properties for three-dimensional orthogonal woven composites. Part II: Multiscale simulation

Woven composites possess multiple inherent uncertainty sources, which leads to the stochasticity of macroscopic mechanical properties. In this work, a multiscale approach is proposed to quantify the uncertainty of macroscopic elastic properties and strengths of three-dimensional orthogonal woven composites. Multiple experimentally quantified uncertainty sources arising from microscale, mesoscale and macro scale are introduced in the multiscale simulation process. In each scale, a series of Statistical Volume Element models involving intra-scale uncertainty sources are constructed to characterize the probability distributions of output mechanical properties. The obtained probabilistic-based mechanical properties in lower scale are converted to high scale by statistical uncertainty propagation methods. Dedicated codes for generating simulation models and statistical techniques (e.g. surrogate models) are implemented to alleviate the manual labor and computational cost of multiscale simulations. The stochasticity of macroscopic properties predicted by the proposed multiscale approach agrees well with the experimental results.

Uncertainty quantification of mechanical properties for three-dimensional orthogonal woven composites. Part I: Stochastic reinforcement geometry reconstruction

For woven composites, the stochasticity of mechanical properties is mainly dependent on the reinforcement variability. Represent Volume Elements with realistic reinforcement architecture can obtain accurate predictions and identify the variability of mechanical properties. This work presents a data-driven modeling framework to generate statistically equivalent RVEs for three-dimensional orthogonal woven composites, in which retaining the knowledge of reinforcement variability from experimental observation. The reinforcement geometry is characterized by Micro CT in terms of fiber tow centroid coordinates and cross-sectional dimensions. A comprehensive slicing and data correction method, which transforms the intact 3D geometry into a four-dimensional dataset, is established for all tow genera. A quantitative understanding of the variability of reinforcement architecture is presented via various statistical descriptors. In order to preserve the mainly statistical characteristics of tow feature parameters, D-vine copula functions are adopted to address their irregular marginal distributions and joint dependence. The reconstructed data is verified by the marginal probability density functions, the bivariate distributions and the correlation matrices of feature parameters. An inverse design from data to textile geometry is achieved by dedicated codes in TexGen. The whole framework is driven by acquired data automatically and can generate any number of statistically equivalent RVEs for further simulations.

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.

Computational schemes on the bending fatigue deformation and damage of three-dimensional orthogonal woven composite materials

This paper reports a computational scheme on three-dimensional orthogonal woven composites (3DOWC) fatigue behavior under three-point low-cycle bending. Based on three-point cyclic bending fatigue tests, a microstructure model was established at yarn level for predicting the fatigue behaviors. The stiffness degradation and damage morphologies of the 3DOWC were obtained from finite element analysis (FEA) and compared with those from experimental. The stress distribution, energy absorption and damage morphologies in the different parts of the 3DOWC sample were obtained to analyze fatigue failure mechanisms. The influences of warp yarns, weft yarns and Z-yarn systems were discussed. It is found that warp yarn system bears the most cyclic load as well as energy absorption. The stress concentration area was located in the central loading area, especially in the warp yarns that is close to the Z-yarns side and its channels. The triangle damage area was gradually generated from up to down in the stress concentration area as the loading cycle increased.

Nonlinear numerical predictions of three-dimensional orthogonal woven composite under low-cycle tension using multiscale repeating unit cells

This paper reports the low-cyclic tensile responses of three-dimensional orthogonal woven composites based on the micro/meso-scale repetitive unit cells with elastic/viscoelastic models. The repetitive unit cell models for the resin impregnated fiber tows and the three-dimensional orthogonal woven composites at the fabric microstructure level were established. In the micro/meso-repetitive unit cells model, a nonlinear viscoelastic relationship with switch rule is introduced to characterize the mechanical behavior of the resin for the loading/unloading conditions. The fiber/fiber tows are characterized with linear elastic models. And damage initiation and postdamage constitutive models are also included for matrix/fiber and matrix impregnated fiber tows in the finite element analysis. The fatigue model with the mechanical parameters transferred from micro-scale to meso-scale model is numerically simulated with user-defined material subroutine and incorporated into commercial finite element software ABAQUS/Standard. The calculated results manifest the multiscale fatigue behaviors of three-dimensional orthogonal woven composites, such as the global stiffness degradation, decrease of peak stress, and even local damage behavior. The fatigue behaviors are also verified with the data in experimental and indicated that the model is an efficient strategy to predict the low-cyclic fatigue behaviors of polymer matrix composites.

Experimental and numerical analyses of the mechanical behaviors of three-dimensional orthogonal woven composites under compressive loadings with different strain rates

Quasi-static and high strain rate compressive behaviors of basalt/vinyl ester 3D orthogonal woven composites along three perpendicular yarn directions were investigated experimentally and numerically. An elastic–plastic numerical model based on the 3D fabric architecture of the 3D orthogonal woven composites was developed to analyze the compressive deformation and failure mode under different strain rate loading conditions. The stress–strain curves obtained from experimental along three directions were used to validate the finite element model. The agreement between the experimental and finite element model results proves the validity of the finite element model. From the experimental results, the strain rate sensitive and anisotropy of the compressive behaviors was found. The finite element results were employed to analyze the locations of stress propagation, the 3D stress state, and the progressive failure behavior. It was also found that this model has a similar failure shape of “broom” at one end of the composite along both of weft and warp compressive directions, while an inclined shear band was formed in through-thickness compression. This result indicates that Z-yarn contributed significantly to the in-plane responses. Additionally, the absorbed energies that induce the complete damage of the composite coupons at various strain rates were also calculated and discussed.

Experimental investigation and numerical simulation of three-point bending fatigue of 3D orthogonal woven composite

This paper reports the three-point bending fatigue behavior of three-dimensional (3D) orthogonal woven composite (3DOWC) in experimental and finite element analysis (FEA) approach. In experimental, the S–N curve was obtained to illustrate the relationship between applied stress levels and number of cycles to failure. The stiffness variation was recorded to present the degradation of mechanical properties of the 3DOWC during the process of fatigue loading. Furthermore, the fatigue damage morphologies of the tested 3DOWC coupons were given to indicate the damage modes of different parts (resin, yarns, and their interface) of the composite under the range of stress levels. In FEA approach, a user-defined material subroutine UMAT which characterizes the stiffness matrix and fatigue damage evolution of the 3DOWC was developed and incorporated with a finite element code ABAQUS/Standard to calculate the maximum deflection of the 3DOWC during each loading cycle. The bending deformation at different loading cycles was also calculated. From the comparisons between FEA and experimental approaches, it is indicated that the proposed model is reasonable for calculating the fatigue bending deformation.

Comparisons of static bending and fatigue damage between 3D angle-interlock and 3D orthogonal woven composites

This paper presents the comparisons of quasi-static three-point bending and fatigue damage behaviors between the three-dimensional angle-interlock woven composite and the three-dimensional orthogonal woven composite. The stress–deflection curves and failure modes were recorded to compare both composites’ mechanical properties under quasi-static bending loading condition. The S-N curves were obtained to demonstrate the comparison of fatigue life under various stress levels between three-dimensional angle-interlock woven composite and three-dimensional orthogonal woven composite. In addition, the damage indexes versus number of cycles (D-N) curves were given to characterize the three-stage cumulative fatigue damage evolution of both types of textile structural composites. Furthermore, the ultimate damage morphologies were compared to deduce the structural effects of the composites under three-point bending cyclic loading condition.

High velocity impact performance of three-dimensional woven composites

Performance of three-dimensional orthogonal woven E-glass/epoxy composites under high velocity impact is presented. The analytical method used is based on wave propagation and energy balance between the projectile and the target. Different damage and energy absorbing mechanisms for a typical three-dimensional orthogonal woven composite are compression of the target directly below the projectile, compression in the surrounding region of the impacted zone, tension in the region consisting of primary yarns, tensile deformation in the region consisting of secondary yarns, shear plugging, bulge formation on the back face of the target, matrix cracking and friction between the target and the projectile. Experimental studies are also presented on high strain rate characterization, shear plugging behavior and high velocity impact behavior. For comparison, studies are also presented on the performance of two-dimensional plain weave E-glass/epoxy composites. A good match is observed between the analytical predictions and experimentally obtained limit velocities for complete penetration. It is observed that limit velocity for complete penetration for three-dimensional woven composite is higher than that for two-dimensional plain weave composite.

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.