Yarn Failure Research Articles

Machine Learning-Based Forecasting of Preliminary Failure Intensity in Three-Dimensional Woven Composites Using Yarn Failure Metrics

Machine Learning-Based Forecasting of Preliminary Failure Intensity in Three-Dimensional Woven Composites Using Yarn Failure Metrics

Dynamic Behavior of Twisted UHMWPE Yarns

Twisting is an effective method to reduce defects during fabric weaving and improve the impact resistance of the armor material. This study examined the dynamic behavior of twisted ultra-high molecular weight polyethylene (UHMWPE) yarns. Material characterization was conducted using three-dimensional X-ray tomography and scanning electron microscopy (SEM). Dynamic mechanical experiments were carried out on the twisted yarns using a Kolsky bar, with the yarn's failure process captured in real time through high-speed imaging. Additionally, the digital imaging correlation (DIC) technique was used to calibrate the strain measured by the Kolsky bar. Post-fracture analysis was performed using SEM. The effects of twisting extent, strain rate, and gauge length on the dynamic behavior of twisted yarns were studied. It was observed that all twisted yarns underwent elongation, shrinkage, fiber breakage, untwisting, and yarn rupture. Furthermore, as the twisting degree and strain rate increased, and the gauge length decreased, the fracture area became more concentrated. The tensile strength peaked at a twisting degree of 250 t/m and decreased thereafter. Moreover, twisting was found to alter the sensitivity of the yarns' stress–strain curves and tensile properties to the strain rate and gauge length.

Ballistic resistance and microwave absorbing properties of a composite made of aramid fabric impregnated with polyethylene glycol and hematite nanoparticles

The ballistic resistance and microwave absorption of a composite of aramid fabric impregnated with polyethylene glycol and hematite nanoparticles was investigated for different hematite concentrations between 0 and 17 wt%. Different damage and energy absorbing mechanisms during ballistic impact were identified: cone formation on the back face of the target, tensile failure of primary yarns and deformation of secondary yarns. In terms of energy absorption, the best results were achieved with 7 wt% hematite, while the smallest depth of penetration (DOP) was observed for a composite with 9 wt% hematite. A scanning electron microscope (SEM) image of the composite with 7% hematite after the ballistic test showed that the main energy absorption mechanism was deformation of secondary yarns. The microwave absorption was measured using the waveguide technique in the frequency range from 8 to 12 GHz. The results showed that the dielectric loss ɛ”/ɛ’ is maximum for a concentration of 3% hematite, while the magnetic loss µ”/µ’ is maximum for a concentration of 11 wt% hematite. A reasonable compromise between ballistic resistance and microwave absorption seems to be a composite with 7 wt% hematite.

Augmenting the mechanical performance of three‐dimensional woven composites by the synergistic effect of fabric architecture and interfacial interaction of carbon nanotubes

AbstractThree‐dimensional (3D) woven fabrics offer many advantages over planar woven fabrics for composite applications. Because of the complex structure of 3D woven fabrics, an in‐depth investigation is needed to understand the effects of fabric architecture and nanofillers on the mechanical and failure behavior of 3D woven composites. The present study investigates the effect of 3D woven ultrahigh‐molecular‐weight polyethylene (UHMWPE) orthogonal fabric architecture, with or without nanofillers, on the mechanical properties of composites. 3D woven orthogonal fabrics with varying proportions of stuffer‐to‐binder (S/B) yarns were manufactured and reinforced with an epoxy (EP) matrix. Multiwalled carbon nanotubes (MWCNTs) were infused as nanofillers to improve the interaction between the UHMWPE fabric and the EP matrix. 3D woven composite having an S/B ratio of 2:1 showed the maximum tensile strength and toughness. On the other hand, 3D woven composite with an S/B ratio of 4:1 showed higher flexural strength and impact resistance. The failure mechanism was also studied by examining the fractured surfaces of composites, which revealed matrix cracking, fiber pullout, predominant binder yarn failure, and yarn slippage. From this study, it is understood that for 3D fabric reinforcement, a balance between structural integrity and load‐bearing capacity of yarns is decisive, whereas for the matrix, the incorporation of MWCNTs is found to be advantageous.Highlights The role of structure of 3D woven orthogonal fabric on the mechanical behaviour of the UHMWPE‐epoxy composite is investigated. The addition of functionalized MWCNTs improves the tensile, flexural, and impact properties. The decisive role of the ratio of stuffer‐to‐binder yarns is established. Matrix cracking, debonding, and yarn failure are observed during tensile failure.

A progressive damage model for 3D woven composites integrating kinking-buckling competition

In this work, a progressive damage model (Kinking-Buckling PDM) considering fiber micro-buckling failure, fiber kinking failure, transverse inter-fiber failure of yarns, matrix failure and interface debonding, is proposed to predict the compressive mechanical behavior of 3D woven composites (3DWC). Fiber kinking and fiber micro-buckling failure are adopted in the form of competition to characterize the longitudinal failure of fiber yarns. A bilinear damage evolution model is established to control the damage accumulation of each constituent. Meanwhile, a material tangent constitutive tensor characterizing the constitutive behavior of 3DWC is derived. The complex failure process of 3DWC under compression is displayed through Kinking-Buckling PDM. As the fiber initial misalignment angle increases, the compressive strength of 3DWC declines significantly, meanwhile, the main failure mode of 3DWC will be transformed from fiber micro-buckling to fiber kinking in warp yarns. The relevant experimental results are used to confirm the accuracy of the PDM.

Parametric theoretical prediction of elastic properties and strength of fine weave pierced C/C composites

This paper developed a parametric model of fine weave pierced carbon/carbon (FWPCC) composites based on the structural relationship of actual sample information. The elastic constants and compressive strengths of FWPCC composites with various Z-directional yarn contents were parametrically investigated. The developed theoretical prediction model agreed well with the experimental data. The parametric prediction results found Z-directional modulus of FWPCC composites with 6 K Z-directional yarns increased by 88.21 % compared to FWPCC composites with 1 K Z-directional yarns; X/Y-directional modulus decreased by 17.32 %; Z-directional compressive strength increased by 337.33 %; X/Y-directional compressive strength only decreased by 6.12 %. The accuracy of the two failure criteria (Hoffmann, Hashin failure criterion) used for the model was compared. The accuracy of the model prediction using Hashin failure criterion was better than that of the Hoffmann criterion. The predicted results using Hashin criterion also showed that under Z-directional compressive loading, the composite failure was mainly the compressive failure of the Z-directional yarns; under X/Y-directional compressive loading, the composite failure was mainly the compressive failure of the fibers in the bending section in the X/Y-directional yarns. The developed theoretical model was of great significance for the engineering application of C/C composite.

PERFORATION AND PENETRATION OF FIBER METAL LAMINATES TARGET BY HEMISPHERICAL PROJECTILE

This study aims to examine the phenomena that occur due to projectile penetration on fiber metal laminate. Ballistic testing was carried out experimentally according to National Institute of Justice standards (NIJ Standard 0101.06 level III-A) using a 9 mm full-metal jacket projectile with a normal angle of attack (90° to the target). The results showed that fiber metal laminate could withstand the projectile rate by penetrating the first layer (aluminum plate) and the second layer (aramid/epoxy), while the last layer was deformed to form a bulge. The pierced aluminum plate is characterized by petalling failure. Meanwhile, the aramid/epoxy was penetrated by the projectile with failure of the primary yarn to break the fiber.

Multi-Scale Analysis for Assessing the Impact of Material Composition and Weave on the Ultimate Strength of GFRP Stiffened Panels

A micro-meso-macro analysis framework based on the multi-scale method was employed to analyse the mechanical behaviour of marine GFRP stiffened panels. The study aims to establish a procedure for assessing the impact of material composition and weave on the ultimate strength of GFRP stiffened panels. The ultimate strength assessment was an essential step in the design process, and the investigation of construction materials has a great benefit to the lightweight design of marine composite structures. The micro- and meso-scale RVE models of components used in GFRP materials are established, and their failure criteria and stiffness degradation models are created using the user-defined material subroutine VUMAT in ABAQUS. The equivalent material properties at the micro-scale (meso-scale) obtained by a homogenisation method are used to define the meso-scale (macro-scale) mechanical properties in the finite element analyses. The multi-scale method assesses the macro-mechanics of composites, and it is shown that the ultimate strength of GFRP stiffened panels is mainly determined by the failure of CSM fibre bundles and WR yarns. Parametric study of the meso-mechanics of composite materials can provide an analysis tool to obtain the optimal macro ultimate strength of the composite stiffened panel.

Impact resistance and yarn pull-out behaviour of polymer spray-coated UHMWPE fabrics

The impact response of polymer spray-coated Ultra-high Molecular Weight Polyethylene (UHMWPE) plain woven fabrics has been studied. Several commercial spray coatings comprising various polymers and adhesives were used on the UHMWPE fabrics. Yarn pull-out tests revealed that the pull-out force significantly increased upon coating the fabric samples, and for rubber-coated samples the peak pull-out force increased by approximately 95 times that of the neat counterpart. Subsequently, two samples that exhibited the highest pull-out load per unit of areal density were selected for ballistic testing using a 12-mm (7.05 g) spherical steel projectile. Impact velocities of the projectiles were in the range of between 140 m/s and 230 m/s. Each sample consisted of four plies of either coated or neat fabrics. It was observed that rubber-coated samples showed the highest specific energy absorption when subjected to ballistic impact and perforation. The neat fabric targets were perforated purely by a wedge-through mechanism, whereas the coated samples were perforated by a combination of wedge-through and yarn failure mechanisms, with a considerable membrane effect. The enhanced pull-out force promoted the cohesive behaviour of the fabric by diminishing the windowing effect. A novel, highly computationally efficient numerical modelling approach was proposed which predicted the residual velocity, pull-out behaviour and the transverse deformation behaviour with high accuracy.

Numerical investigation on tensile behavior of three-dimensional six-directional braided composites

Based on the mesostructure, a parametric finite element (FE) model of the three-dimensional six-directional (3D6d) braided composites was developed considering the real cross-sectional shape of the yarn and its contact relationship. The 3D Hashin criterion and maximum stress criterion were used for failure determination and periodic displacement boundary conditions were imposed on the model to numerically simulate the initiation, propagation and final failure of yarns and matrix damage. The FE model accurately predicts the longitudinal tensile strength of 3D6d braided composites and simulates the progressive damage process associated with the stress-strain behavior. The longitudinal mechanical properties of the 3D6d braided composites decrease with increasing braiding angle, while increasing the fiber volume fraction leads to enhancement of these properties. Furthermore, the change rate of longitudinal mechanical properties with braiding angle is relatively stable, and the influence of fiber volume fraction on longitudinal properties decreases with the increase of braiding angle. For the damage mode, the increase of braiding angle makes the damage of braiding and sixth-directional yarns gradually change from single direction to multiple directions, and the decrease of fiber volume fraction makes the damage of braiding and fifth-directional yarns at the peak stress more serious.

Mechanical behavior and failure mechanism of the 3D angle interlocking woven reinforced aluminum matrix composites under in-plane tensile loading

3D angle interlocking fabric reinforced aluminum composites were prepared by the vacuum assisted pressure infiltration method. The mechanical properties and damage behavior of the composites subjected to in-plane tensile loading were investigated using the micromechanical finite element simulation and experimental method. The results show that the tensile stress-strain curve from simulation is in agreement with the testing curves, where the calculation errors of the initial modulus, ultimate strength and fracture strain in warp (weft) direction are 3.96%(1.11%), 1.40%(6.86%) and −5.49%(3.73%), respectively. Under the warp directional tension condition, the interface on warp yarns and the adjoint matrix alloy damage successively. With the increase of tensile strain, these damage zones accumulate and interact with each other, leading to the failure of interface, matrix and weft yarns in sequence. The fracture of warp yarns in the terminate stage induces the ultimate failure of the composites. During the weft directional tensile process, the interface on warp yarns and the thin matrix alloy between yarns damage and fail firstly. The transverse fracture of warp yarns occurs in the middle stage of tensile deformation. The axial fracture of weft yarns, which sustain the loading stress at the end of deformation process, is the main failure mechanism of the composites under weft directional tensile condition. The tensile modulus and strength in weft direction are 81.8% and 56.5% times than those in warp direction, owing to the lower volume fraction of weft yarns in the 3D angle interlocking fabric.

Per-phase spatial correlated damage models of UD fibre reinforced composites using mean-field homogenisation; applications to notched laminate failure and yarn failure of plain woven composites

A micro-mechanical model for fibre bundle failure is formulated following a phase-field approach and is embedded in a semi-analytical homogenisation scheme. In particular mesh-independence and consistency of energy release rate for fibre bundles embedded in a matrix phase are ensured for fibre dominated failure. Besides, the matrix cracking and fibre-matrix interface debonding are modelled through the evolution of the matrix damage variable framed in an implicit non-local form. Considering the material parameters of both fibre and epoxy matrix phases identified from manufacturer data sheets, it is shown that the failure strength of a ply loaded along the longitudinal direction is in agreement with the reported values. Finally, the multi-damage homogenisation framework is applied to model, on the one hand, the failure of a notched laminate, in which case the failure modes are observed to be in good agreement with experiments, and, on the other hand, the failure of yarns in a plain woven composite unit-cell under uni-axial tension.

Reverse engineering for estimation of shear modulus for yarn models in finite element modelling for ballistic impact

In finite element (FE) modelling of ballistic performance of fabric, shear moduli of continuous yarn models are usually specified based on approximations and assumptions, despite their significant influence on energy absorption and yarn failure time in a ballistic impact event. This paper applies reverse engineering method for estimating shear modulus G13 of a continuous multifilament yarn model for simulating the ballistic behaviour of the yarn or its fabric. A ballistic event of Dyneema® SK65 yarn model impacted by a projectile travelling at 477 m/s is used to illustrate the establishment of the methodology. The procedure starts by relating G13 and transverse wave velocity (ut) through regression whose correlation factor R2 is 0.999. ut is calculated by the classical Smith equations. The regressed relation and the availability of ut value enable the calculation of G13. The simulated results of the Dyneema® yarn model with such estimated G13 show healthy agreements to the analytical and experimental counterparts in terms of ut and the slope angle of fabric deflection θ. The reverse engineering method has been used for obtaining G13 successfully for yarn models of other materials, e.g. Kevlar KM2 and Zylon®, in simulating their transverse deflection behaviour under the ballistic impact.

Experimental analysis and damage modeling of the shear-out failure mode of a 3D woven composite lug

This study focuses on the shear-out failure mode of a 3D-woven composite lug. The damage scenario leading to the failure is analyzed based on a tensile test on a lug. The shear-out failure of the lug is shown to be driven by matrix damages generated by in-plane shear. No yarn failure is observed. A matrix damage model is proposed to capture the shear-out failure of the lug. This model combines the Onera Damage Model for Polymer Matrix Composite (ODM-PMC) with a Mazars-like damage evolution law. A special attention is paid for the transition between both evolution laws, in order to ensure the continuity of the damage evolution. The model is implemented into the commercial Abaqus Standard finite element (FE) software. A 3D FE analysis of the shear-out failure of the lug is performed. The simulation is able to reproduce the load plateau observed in the global behavior of the lug as well as the specific matrix damage patterns.

The structural effects on the impact response of ultra-high-molecular-weight polyethylene plain weaves

This paper investigates the penetration and energy absorption mechanisms of ultra-high-molecular-weight polyethylene plain weaves with different fabric properties. Impact tests along with finite element (FE) analysis were used to study the impact response of the fabrics. In this research, the impacting projectile did not cause any fiber or yarn failure on the samples. It was found that structural parameters determine the yarn pull-out behavior and the softness of the resultant fabrics. Fabrics formed by loosely interlaced yarns tend to exhibit higher softness and less resistance against yarn pull-out. When the projectile velocity is not sufficient to initiate yarn pull-out, material softness determines the depth of the backface signature on the clay witness. This trend is more pronounced in a multi-ply fabric system than in a single-ply system; when yarn pull-out occurs, the projectile-slowing mechanism depends on the frictional force between the warp and weft yarns. Therefore, fabric softness becomes less important, and the yarn pull-out behavior of the fabric plays a predominant role in energy absorption. FE prediction showed that tightly woven fabrics exhibit a larger area of stress distribution and material deformation than those with severe yarn pull-out and, consequently, these tight fabrics tend to absorb more kinetic energy and sustain higher impact load from a projectile.

Multiscale modeling of mechanical behavior and failure mechanism of 3D angle-interlock woven aluminum composites subjected to warp/weft directional tension loading

The mechanical behavior and progressive damage mechanism of novel aluminum matrix composites reinforced with 3D angle-interlock woven carbon fibers were investigated using a multiscale modeling approach. The mechanical properties and failure of yarns were evaluated using a microscale model under different loading scenarios. On this basis, a mesoscale model was developed to analyze the tensile behavior and failure mechanism of the composites. The interfacial decohesion, matrix damage, and failure of fibers and yarns were incorporated into the microscopic and mesoscopic models. The stress–strain curves and fracture modes from simulation show good agreement with the experimental curves and fracture morphology. Local interface and matrix damage initiate first under warp directional tension. Thereafter, interfacial failure, weft yarn cracking, and matrix failure occur successively. Axial fracture of warp yarn, which displays a quasi-ductile fracture characteristic, dominates the ultimate composites failure. Under weft directional tension, interfacial failure and warp yarn rupture occur at the early and middle stages. Matrix failure and weft yarn fracture emerge simultaneously at the final stage, leading to the cata-strophic failure of composites. The weft directional strength and fracture strain are lower than the warp directional ones because of the lower weft density and the more serious brittle fracture of weft yarns.

A numerical study on the mechanisms of Dyneema® quasi-isotropic woven panels under ballistic impact

Quasi-isotropic (QI) fabric panels were recently found to have a promising performance against ballistic impact, compared with the aligned panels, since more areas in the followed plies are transversely deformed in the QI panels forced by the front plies. However, the ballistic mechanisms of QI panels have not been completely elucidated. This study aims to identify the ballistic mechanisms of QI woven fabric panels using finite element method (FEM), focusing on the interference from the back plies towards the front. A yarn-level Dyneema® woven fabric model was created, and then validated by the ballistic test results. 2-ply, 3-ply and 4-ply aligned and QI panels were investigated in terms of energy absorption, the initial time of yarn failure, penetration time of panels, and stress distribution within different plies. ImageJ® software was used to quantify the areas under stress in different scale ranges in different plies. It was found that QI panels absorbed 6%–8% more energy than aligned panels, and were less vulnerable to be perforated. Moreover, compared with the aligned panels, QI panels overall had approximately 10% larger areas stressed in the front plies. These results were attributed to the fact that QI panels have higher efficiency in stress distribution along the primary yarns in the front and middle plies. The higher efficiency afterwards was ascribed to the higher interference between plies in the QI panels. This study demonstrated the importance of interference in QI panels on stress distribution, and the findings are of great significance for guiding further designs of fabric and composite panels for the ballistic protection.

Meso-scopic model for progressive failure of resin impregnated yarns in composite overwrapped pressure vessels (COPVs)

ABSTRACT Composite Overwrapped Pressure Vessels (COPVs) are widely used in space launch vehicles and the automotive industry. Due to the potential for catastrophic loss caused by failure of COPVs, improved understanding of its mechanical and damage growth behavior is necessary to ensure its safe operation. In this paper, we described a developed mesoscopic model with the capability of modeling tows/yarns with inserted, in-ply interface elements and interface layers as resin rich zones. Furthermore, the model realizes 1) arbitrary winding angle build-up of overwrap plies, 2) controllable detailed dimensions, and 3) user defined material behavior for all regions. These features are critical for potential studies of in-situ and parametric overwrap failure in COPVs. In the present work, stress profiles and progressive failure around a single tow break are shown by case studies involving various interface and damage evolution properties. The investigation indicates that the strength and damage evolution law of interface elements both have direct effect on the stress concentration factors and damage evolution around a tow break/fracture. Resulting physical phenomena and stress overload profile are discussed as well.

The role of friction in cylindrical projectile impact on fabric structure

A three-dimensional finite element analysis model for plain weave fabric was created. Impact of a rigid cylindrical projectile on a square fabric clamped along its four edges were simulated using commercially available software LS-DYNA. To reveal the role of friction in ballistic impact, comparative study was conducted in which projectile velocity, boundary condition, and material property are kept the same but friction between projectile and fabric and between yarns themselves are varied systematically. Results from the study show that the friction between projectile and fabric has little effect on fabric energy absorption but the friction between yarns themselves has apparent effect. Fabric has larger impact energy absorption capacity when friction coefficient between yarns are smaller. Smaller friction between yarns delays initiation of yarn failure, increases the duration of interaction between projectile and fabric and thus increases impact energy absorption capacity of fabric structure.

Initial failure strength prediction of woven composites using a new yarn failure criterion constructed by deep learning

A new failure criterion for fiber tows (i.e. yarns) is developed based on a micromechanical model using the mechanics of structure genome (MSG) and a deep learning neural network model. The proposed failure criterion can be applied to yarns in mesoscale textile composites modeling while capturing the failure initiation at the fiber and matrix level. A plain weave fiber reinforced composite material example is used to compute the initial failure strength constants of a woven lamina based on the proposed yarn failure criterion. To study the accuracy and efficiency of the failure criterion, a comparison to a meso-micro coupled model explicitly capturing the failure initiation at fiber and matrix level is performed. Moreover, the differences between the mesoscale modeling results based on the proposed criterion and other yarn failure criteria (i.e. maximum stress, Tsai-Wu, and Hashin) are studied. Lastly, the failure envelope analysis of the mesoscale plain weave example is carried out using the MSG solid model to further demonstrate the accuracy and efficiency of the new yarn failure criterion under combined loading conditions.