High-velocity Impact Damage Research Articles

High-Velocity Impact Damage Assessment of Aluminum-Honeycomb-Cored Banana-Fiber-Reinforced Composite Structures Under Elevated Temperatures

High-Velocity Impact Damage Assessment of Aluminum-Honeycomb-Cored Banana-Fiber-Reinforced Composite Structures Under Elevated Temperatures

Experimental and numerical investigation on the compression after high-velocity impact behavior of composite laminates

Considering the differences in damage mechanism between high-velocity impact (HVI) and low-velocity impact (LVI), this study conducted HVI tests and compression-after-impact (CAI) tests to reveal the post-impact compression behavior of laminates manufactured by unidirectional prepreg tape and exposed a completely different mechanical response in residual strength compared to that of LVI. By controlling the impact velocity within the range of 200 m/s ̃ 380 m/s, three kinds of impact results were obtained, including un-penetrated and penetrated conditions. Different CAI damage morphologies can be observed in these laminates. In order to fully understand the CAI damage mechanism induced by different HVI events, a surface-based cohesive behavior and a CDM intralaminar damage model were implemented. In addition, a more complete picture of the compression behavior after HVI was observed through the simulation results, which is of great help in estimating the residual strength of post-impact laminates. However, the HVI damage was introduced through the spherical steel projectiles, and the sample size was determined based on ASTM D7137, which might be different factors from the application conditions.

High-velocity impact damage by projectile and tension after impact behavior at 1300 ℃ for SiC/SiC with environment barrier coating

The research on the high-speed & low-energy impact under millimetre sized projectile and residual strength under high temperature are rare for SiC/SiC with Environmental Barrier Coatings (EBC). The impact of 2 mm steel projectiles at the speed of 177.5 m/s–252.7 m/s was studied for EBC(Si/Yb2Si2O7/Yb2SiO5)-SiC/SiC with Chemical Vapor Infiltration (CVI) process. The tensile test at 1300 ℃ was conducted on an inert gas protection testing machine. The optical microscope, Scanning Electronic Microscope(SEM), μCT were used to observe the impact and tension after impact(TAI) damage. The results shows that projectile impact has strong effect on EBC peeling, SiC/SiC damage and fracture, and residual-tension strength at 1300 ℃. And the threshold values of impact velocity or energy are different for them. Furthermore, an analysis method for damage evolution by the attachment quantity of oxide was found for EBC-SiC/SiC composites.

Effect of stitch density on the damage inhibition and compression strength after high-velocity impact of UHMWPE fiber composites

This paper investigates the effect of stitch density on the high-velocity impact damage inhibition and CAI (compression after impact) strength of UHMWPE (Ultra-High Molecular Weight Polyethylene) fiber composites. The damage response and compression behavior after impact were quantified and analyzed using CT scanning and DIC (Digital Image Correlation) techniques. The findings reveal that the delamination area of the composite plate with the stitch space of 1 cm reduces by 49.14 % compared to the unstitched sample, and exhibits a 73.05 % higher compressive load than the plate with a 4 cm stitch space. Notably, the 4 cm stitch composite plates demonstrate a significant advantage in energy absorption. However, the sparse stitch structure destroys the original structure inside the composite, resulting in a degradation of CAI performance. The study provides guidance for the practical design of composite materials with enhanced energy absorption and damage resistance.

Durable and impact-resistant thermoset polymers for the extreme environment of low Earth orbit

Polymers degrade rapidly in low-Earth orbit (LEO) due to extreme thermal cycling, solar radiation, micrometeoroid and orbital micro-debris impact, and the synergistic erosive effects of atomic oxygen (AO) with UV radiation. In this work, we investigate the synergistic effect of (AO+UV)-induced erosion and high-velocity impact damage on a tough thermoset, polydicyclopentadiene (pDCPD), via erosion yield measurements after a long-term LEO exposure in the ram orientation aboard the International Space Station (ISS) followed by ground-based hypervelocity impact tests. The incorporation of SiO2 nanoparticles reduces the AO-erosion rate by an order of magnitude, while also mitigating the associated degradation of surface mechanical properties. Moreover, the resistance of pDCPD to AO-erosion increases with crosslink density. Hypervelocity impact tests using sub-millimeter laser-driven flyer plates launched at 4.5 km s−1 reveal that pDCPD has higher impact resistance than epoxies with comparable erosion resistance. Interestingly, both epoxy and pDCPD exhibit a statistically insignificant change in impact resistance following surface AO-erosion during direct exposure to space vehicle ram conditions (7.8 km s−1) in LEO.

High-velocity impact damage and compression after impact behavior of carbon fiber composite laminates: Experimental study

In this paper, the impact resistance of carbon fiber/resin composite laminates with a thickness of 2.5 mm at different impact velocities, angles and positions was investigated experimentally. In the process of high-velocity impact, fiber shear failure and tension failure are the main failure modes. When the impact velocity is 300 m/s, the fiber tension failure and matrix compression failure under oblique impact are more than that under normal impact, and the energy absorption of laminates is also lager than that under normal impact. The ballistic limits, energy absorption and delamination area of the center and edge impact of laminate are similar. In addition, the CAI tests are conducted to study the influence of different positions on the residual compressive strength of laminates after high-velocity impact, and the fracture loads and failure modes of two impact positions are quite different. The failure modes of the center impact laminate are main buckling failure, and the failure modes of the edge impact laminate are compression failure near the bullet hole side of the fixture and buckling failure near the center of the laminate. The research results can provide a reference for the residual strength of laminates after impact at different locations in practical situations.

The origin of high-velocity impact response and damage mechanisms for bioinspired composites

Natural materials such as nacre abalone shells are often leveraged for inspiration in developing high-performing materials for impact protection applications. However, a comprehensive understanding of the microstructure-property relationships and their corresponding damage mechanisms in bioinspired designs under high-speed impact has not yet been fully studied. In this paper, the mechanism of the high-speed impact performance of nacre-inspired microstructures is presented, considering a set of design parameters using high-throughput computational simulations. Results show that adding interfacial waviness to traditional nacre designs enlarges the damage area, and an inclined interface helps to effectively block the crack and stress wave propagation, leading to superior impact performance. Moreover, an asymmetric microstructure tends to rotate an impactor, causing it to travel a longer path yielding larger energy dissipation. It is envisioned that pinpointing the superior features embedded in nacre-like structures can provide unique design guidelines for next-generation impact-resistant materials. • Impact resistance of bioinspired composites studied using computational simulations • Toughening mechanisms presented by investigating crack and stress wave propagations • Microstructural design effects on impact performance under different velocities Lee et al. present the mechanism of high-speed impact performance of bioinspired microstructural designs using high-throughput computational simulations. Results show that adding interfacial features such as waviness and incline can enlarge the damage area and help to effectively block the crack and stress wave propagation, leading to superior impact performance.

Experimental investigation on high-velocity impact damage and compression after impact behavior of 2D and 3D textile composites

This paper investigates the impact resistance and damage tolerance of 2D triaxially braided composites and 3D angle-interlock woven composites panels using high-velocity impact tests and compression after impact tests. Both materials present equivalent impact resistance with similar ballistic limit and energy absorption ratio. Nevertheless, the damage patterns of the two materials are quite different, among which, 2DTBC is characterized by global response and yarn debonding, while 3DAWC is characterized by localized damage without yarn debonding. However, in compression after impact tests, 3DAWC exhibits higher damage tolerance because the binder yarns resist buckling failure and kink bands formation during compression, resulting in higher residual compressive strength. In addition, how the damage morphology varies spatially due to the different deformation and damage modes caused by high-velocity impact is learned from X-ray CT scanning. Different from the relationship between impact energy and residual compressive strength pointed out by most research, this study also reveals a unique trend of residual compressive strength as a function of impact energy, considering both penetration and rebound conditions.

Study the damping and vibrational properties of polycarbonate reinforced ZrO2

In this paper, the effect of nano zirconia particles on damping characteristics of polycarbonate composites was investigated experimentally. The nano particles were added to polycarbonate matrix with five different weight percentage (wt %). Polycarbonate Nanocomposites filled with pristine and modified ‎Zirconium dioxide were prepared by simple melt compounding. All samples ‎were prepared by an injection molding process. The samples were studied before and after damage. Damage process was done with high velocity impact. The half-power bandwidth method was used to experimentally estimate the damping ratio. The experiments were designed based on an impulse actuator signal generated by the ‎shaker, and the responses were recorded using accelerometer sensors. The results of experiments showed that the damping properties of the composite were increased by adding nanoparticles to 3 wt% and decreased gently for samples with the upper content of nanoparticles. Transmission electron microscopy (TEM) pictures were used to investigate the distribution of nano zirconia on the polycarbonate matrix and showed a homogeneous mixture of nanocomposites and strong bonding between zirconia and polycarbonate that increased damping properties and decreased vibration. Finally, the experimental modal analysis test was done after high-velocity impact damage process to investigate the effect of defection on the nano polycarbonate composites. The results showed a great decline in vibration and an increase of damping properties.

High-velocity impact response of titanium-based fiber metal laminates. Part II: Analytical modeling

This two-part article scrutinizes the influence of metal layer distribution through the thickness of titanium-based fiber metal laminates (FMLs) on their high-velocity projectile impact response and damage. The four different layups of FMLs consist of layers of glass fiber/epoxy and Ti-6Al-4V titanium alloy sheets, exhibiting the thickness of the total metal layer the same. Part I presents the experimental investigations of fully clamped FMLs demonstrating performance parameters, damage mechanisms, and ballistic resistance. Part II concerns the ballistic impact behavior of FMLs using analytical modeling, which is based on test results obtained in an accompanying study. An equivalent mass-spring system is used to obtain the transient deformation, ballistic limit, and absorbed energy of the laminate by various mechanisms. Good agreement is obtained between experimental and analytical ballistic limit velocity. The foremost part of the total energy absorption is by bending and membrane energy absorption (68 % - 72 %), with FML 4/3-0.3 absorbing a higher percentage of aforementioned energies followed by that of both FMLs 3/2 and FML 2/1-0.6. The predicted total energy absorption by several damage mechanisms of FMLs at the ballistic limit displays a reasonable matching with experiments.

High Velocity Impact Response and Damage Mechanism of an Aluminium/Glass-Carbon Fiber/Epoxy Composite Plate Reinforced with Graphene Nano-plates

The interface of fiber-polymer matrix has a critical role in controlling the mechanical features of polymer composites. Most of the studies focused on the application of reduced graphene oxide in enhancing the interfacial properties of the composite. In this study, we focused on utilising the Graphene nano-plates (GNPs) with average diameter of 5–10 µm. The GNPs were assessed by different techniques of XRD and AFM. The GNPs incorporated into the epoxy matrix, and then the high velocity impact response was evaluated. The result of GNPs incorporation into the epoxy matrix showed that the 0.3 wt.% GNPs incorporation into the glass fiber epoxy matrix and 0.9 wt.% GNPs incorporation into the glass-carbon fiber/epoxy were destructive on the absorption energy of the composite. The optimum concentration of the incorporated GNPs highly dependent upon the type of fiber in the matrix and the level of initial velocity in the impact test. Although the high concentration of GNPs (up to 0.9 wt.%) dispersed at the interface of the glass fiber/epoxy resin can induce the high velocity impact performance, but it resulted in the reduction of the impact performance of glass-carbon fiber/epoxy due to the agglomeration of the GNPs.

Numerical Methodology for Aerostructures Hail Impact Damage Prediction

The two numerical approaches for modelling of soft-body impact in Abaqus/Explicit have been applied in this work for prediction of high-velocity hail impact damage in aeronautical structures. The applied methods are the CEL (Coupled Eulerian Lagrangian) and SPH (Smoothed Particle Hydrodynamics), while the impacted structure is a metallic slat structure. Comparison of the CEL and SPH methods has been performed by impact simulations at a rigid plate, aimed to validate the applied material model, and by simulation of the slat structure impact. Two material models have been applied to study the effect of high strain-rates at the damage process in the metallic structure. The first is the standard isotropic plasticity model that defines material failure based on the value of equivalent plastic strain. The second constitutive model in the analyses is the Johnson-Cook model that includes the effects of strain rate and temperature on the material failure process. The simulations have been stable, illustrating the robustness of Abaqus/Explicit in these highly nonlinear impact cases. Compared to the CEL, the SPH method is computationally more efficient.

High-velocity ice impact damage quantification in composite laminates using a frequency domain-based correlation approach

This paper investigates the feasibility of using a novel domain-based correlation approach derived from the complex frequency domain assurance criterion (CFDAC) for the detection and quantification of impact damage in composite laminates. The CFDAC is essentially a complex-valued two-dimensional indicator of the covariance between two sets of frequency response functions for each pair of spectral lines corresponding to vibration-response of pristine and damage states. The study focuses on damage induced by high-velocity ice impacts on carbon fiber laminated plates. The experimental results demonstrate that the proposed methodology correctly identifies the level of induced damage via a user-independent scalar damage indicator. Therefore, this approach has potential use as a damage indicator, which could be adapted as a structural assessment non-destructive method. This research aims to contribute to the further development of functional, autonomous, and reliable structural health monitoring systems for composite structures based on spectral-domain indices.

Compression after ballistic impact response of pseudoelastic shape memory alloy embedded hybrid unsymmetrical patch repaired glass-fiber reinforced polymer composites

This paper investigated the influence of embedding pseudoelastic shape memory alloy within the external bonded patch made up of glass fibers on the compression after impact response of adhesively bonded external patch repaired glass/epoxy composite laminates. Unsymmetrical patch repair was employed in the current studies. Three innovative pseudoelastic shape memory alloy configurations (straight wired, meshed and anchored) were embedded inside the patch and the changes in high-velocity impact response and damage tolerance at four impact velocities (70, 85, 95, 105 m/s) were compared with the conventional glass/epoxy (glass fiber-reinforced polymer) patch. Anchored specimens showed the best response by improving the compressive strength by 25% under non-impacted conditions and restoring it by 88%, 77%, 29%, and 28% at the impact velocity of 70, 85, 95, and 105 m/s, respectively, in comparison to the conventional normal specimens.

Damage of Hygrothermally Conditioned Carbon Epoxy Composites under High-Velocity Impact.

The influence of hygrothermal aging on high-velocity impact damage of carbon fiber-reinforced polymer (CFRP) laminates is investigated. Composite laminate specimens were preconditioned in water at 70 °C. The laminates were subsequently impacted by flat-, sphere-, and cone- ended projectiles with velocities of 45, 68, and 86 m/s. The incident and residual velocities were collected during the impact test. The impact-induced damages were measured by ultrasonic C-scan, a digital microscope system, and a scanning electron microscope. The results show that the hygrothermally conditioned laminates offer a higher energy absorption during high-velocity impact. Due to the weakening of the interlaminar properties, the hygrothermally conditioned laminates are more susceptible to delamination failure, and shear-induced debonding dominates. The projected delamination area increases with the increment of impact velocity. The damaged region becomes close to a circular shape after hydrothermal conditioning, and close to a rhomboidal shape for the dry specimens.

Effect of strain rate, off-axis loading and high-velocity impact damage on the compressive strength of C/SiC composite

The compressive strength of C/SiC composite at different strain rates, off-axis orientations and after high-velocity impact was studied. The compressive strength was found to be 137 ± 23, 130 ± 46 and 162 ± 33 MPa at a strain rate of 3.3 × 10−5, 3.3 × 10−3, 3.3 × 10−3 s−1, respectively. On the other hand, the compressive strength was found to be 130 ± 46, 99 ± 23 and 87 ± 9 MPa for 0°/90°, 30°/60° and 45°/45° fibre orientations to loading direction, respectively. After high-velocity impact, the residual compressive strength of C/SiC composite was found to be 58 ± 26, 44 ± 18 and 36 ± 3.5 MPa after impact with 100, 150 and 190 m/s, respectively. The formation of kink bands in fibre bundles was found to be dominant micro-mechanism for compressive failure of C/SiC composite for 0°/90° orientation. On the other hand, delamination and the fibre bundles rotation were found to be the dominant mechanism for off-axis failure of composite.

High velocity impact damage investigation of carbon/epoxy/clay nanocomposites using 3D Computed Tomography

A series of projectile impact tests have been carried out on cross ply carbon/epoxy and different weight percentages (1%, 3% and 5%) of nanoclay dispersed in the carbon/epoxy laminated composites of two different thicknesses (3 mm and 5 mm) with a 9.8 mm diameter hemispherical shaped mild steel projectile for determining the ballistic limit, residual velocity and energy absorption. Velocities far higher than the ballistic limit such as 165 m/s, 195 m/s and 220 m/s are considered for investigation of damage mechanisms. The traditional CFRP composites show poor impact resistance due to their negligible plastic deformation as compared to metals. The impact performance of these composites can be enhanced by the clay effect. The optimum clay content is proposed in the present investigation. There is a significant improvement in impact properties, as the clay content increases from 0 wt% to 3 wt% but beyond 3 wt% of clay, the properties degrade which is due to the high stress concentrations attributed to the clay clustering in the higher clay content. The X-ray computed tomography (X-ray CT) scanning analysis which is an advanced non-destructive technique (NDT) is used to investigate the internal defects such as delamination and porosity of impact damaged specimens whereas fiber breakage and matrix cracks are seen in scanning electron microscopy (SEM) images.

Role of Hydrogen Abstraction Reaction in Photocatalytic Decomposition of High Energy Density Materials

Explosive phenomena includes a stunningly wide range of diverse manifestations, such as supernova remnant shocks and solar flares, violent decomposition chemistry and synthesis of superior materials under extreme conditions, weapons, missiles, and high velocity impact damage, fuels for space rocket motors, festive fireworks, and applications of detonation waves in construction industry and shocks in medicine. With earliest stages of explosive chemistry in energetic materials remaining poorly understood and constantly posing new science questions, an achievement of a controllable initiation of detonation process represents a particular challenge. Precise tuning of sensitivity to initiation of detonation via photo-excitation appears unreachable because all known secondary explosives are wide band gap insulators. This research demonstrates how YAG:Nd laser irradiation triggers explosive decomposition of PQ-PETN composites formed by pentaerythritol tetranitrate (PETN), high energy density material, mixed with...

Explicit multiscale modelling of impact damage on laminated composites – Part II: Multiscale analyses

This work describes a multiscale impact damage prediction methodology for laminated composite structures which is based on the HFGMC micromechanical model and the MMCDM damage formulation. The numerical approach is intended for application within explicit finite element analyses and has been employed for modelling of high-velocity impact damage in laminated composite structures. Structural-scale applications and the multiscale framework of the method are presented in this paper whereas introduction and validation of the methodology have been presented in Part I of the paper.By applying the described method, the micromechanical model calculates the local stress/strain fields within the unidirectional composite material, whereas the structural-scale computations have been performed employing Abaqus/Explicit. The Mixed Mode Continuum Damage Mechanics (MMCDM) theory has been utilised as to model the damage and failure modes of the composite material at the micromechanical level. As demonstrated in the Part I paper, the HFGMC and MMCDM model enable modelling of the microdamage nonlinearities at in-plane shear and transverse compressive loading of the composite plies. The micromechanical damage modelling approach has been employed at high-velocity soft-body impact on CFRP and GFRP composite plates in this work. Results of the multiscale damage model have been validated using available experimental data and by comparison with the numerical results obtained using the commonly used ply-level failure criteria and damage models.

High-Velocity Impact Damage Behavior of Carbon/Epoxy Composite Laminates

In this paper, the impact damage behavior of USN-150B carbon/epoxy composite laminates subjected to high velocity impact was studied experimentally and numerically. Square composite laminates stacked with [45/0/-45/90]ns quasi-symmetric and [0/90]ns cross-ply stacking sequences and a conical shape projectile with steel core, copper skin and lead filler were considered. First high-velocity impact tests were conducted under various test conditions. Three tests were repeated under the same impact condition. Projectile velocity before and after penetration were measured by infrared ray sensors and magnetic sensors. High-speed camera shots and C-Scan images were also taken to measure the projectile velocities and to obtain the information on the damage shapes of the projectile and the laminate specimens. Next, the numerical simulation was performed using explicit finite element code LS-DYNA. Both the projectile and the composite laminate were modeled using three-dimensional solid elements. Residual velocity history of the impact projectile and the failure shape and extents of the laminates were predicted and systematically examined. The results of this study can provide the understanding on the penetration process of laminated composites during ballistic impact, as well as the damage amount and modes. These were thought to be utilized to predict the decrease of mechanical properties and also to help mitigate impact damage of composite structures.