Residual Velocity Of Projectile Research Articles

High velocity steel spheres impact and damage analysis of graphene doped T700 composite shielding panels

Composite materials are increasingly being used in aircraft components such as fuselage panels which are subject to collision with debris during take-off/landing or in flight. This article provides an analysis of the impact resistance capability of graphene doped T700 (T700G) multilayer composite, when subjected to steel projectile impacts. Test coupons with 300×300 mm were impacted by steel spherical projectiles, with impact energies ranging from 34 J to 338 J, using a compressed air operated cannon. Test data, such as impact and absorbed energy were determined through impact and residual projectile velocity, acquired using ballistic chronograph and two high speed cameras. Damage assessment was performed using non-destructive techniques such as Ultrasonic testing before and after impact test. Through modelling and simulation, using ABAQUS/Explicit, and recording the change of projectile velocity, the energy loss of projectile is calculated, and the impact resistance is judged together with damage extent. T700G has similar impact resistance to AL2024, underperforming when impacted by larger projectiles and presenting an overall higher damaged area.

Data-driven modeling for residual velocity of projectile penetrating reinforced concrete slabs

The penetration of projectiles into reinforced concrete (RC) structures is crucial for defense technology. However, accurately estimating the resistance of RC structures to projectile penetration is challenging due to complex parameter nonlinearities. This paper proposes a data-driven modeling methodology that combines validated finite element (FE) simulations with machine learning (ML) algorithms to investigate the penetration resistance of RC slabs against projectiles. The methodology employs an extreme learning machine (ELM) network to identify extreme conditions characterizing penetration resistance, reducing data requirements, and improving prediction efficiency. Predicted results from the ELM network are then used as input for a recurrent neural network (RNN) to predict residual velocity curves over time, a crucial metric for evaluating penetration resistance. To cover various loading scenarios, 64 sets of FE models with different incident velocities, caliber-radius-head (CRH), and projectile masses are developed based on available experimental studies. The Johnson-Holmquist II model and Johnson-Cook model are employed for concrete and steel, respectively, to describe material behavior at high strain rates. The FE prediction results form a training sample database, and ML models are established using CRH, incident velocity, and projectile mass as input layers and projectile residual velocity as the output layer. The results demonstrate high Pearson correlation coefficients of 0.984 and 0.991 for the ELM and RNN prediction results, respectively, with numerical simulation results. The proposed networks provide accurate and efficient alternatives to time-consuming FE simulations for predicting projectile penetration performance. This strategy offers a new ML-based method for rapid evaluation, particularly for in-situ applications.

A study of high-velocity penetration on icy lunar regolith simulants

Understanding the mechanical response of a high-speed penetrator penetrating icy lunar regolith (ILR) is essential for designing penetrators in lunar permanently shadowed regions and interpreting the detection data from the device. Experimental research on the penetrators is limited in engineering due to the difficulties in preparing large-scale icy lunar regolith simulants (ILRS). Such limitation urges the need to construct a theoretical model and verify a numerical simulation model based on the scaled-down penetration experimental results, which provide insights into the mechanical response of penetrator penetrating ILR. Projectile penetration experiments were conducted on ILRS targets with four typical water content levels in a cryogenic chamber at 110 K. The experimental results show that the ILRS with higher water content exhibits greater brittleness and a faster crack growth rate. Consequently, the diameters of cratering and scabbing areas are augmented on the target surface upon projectile penetration. Moreover, increased mechanical strength decreases the plugging height on the ILRS targets. Based on the projectile residual velocities, the equivalent target strength parameter R were calculated and fitted to a functional relationship with the uniaxial compressive strength. RHT model parameters were calibrated using the test results of the dynamic and static mechanical properties of the simulants. Numerical simulation of projectile penetration into semi-infinite and thick targets were conducted using the calibrated model. The simulation results demonstrate high consistency with the experimental and theoretical calculations, indicating the effectiveness of the constitutive model in describing the mechanical response of the ILRS under projectile penetration.

Ballistic impact modeling of woven composites using the microplane triad model with meso-scale damage mechanisms

Existence of undulating fill and warp yarns in woven composite laminae introduces complex unit cell geometries and multi-scale interactions among the constituents. Due to these, the failure process involves various meso-scale constituent-level failure modes under complex loading scenarios such as ballistic impact. This can be challenging to model via conventional macro-scale damage tensor-based models. This challenge is tackled here via the adaptation of the previously developed multi-scale microplane triad model to ballistic impact of woven composites. The model can resolve meso-scale constituent level details (including yarn undulations) and predict not only the elastic constants of a woven lamina but also its fracturing behavior. In the present adaptation, only two damage laws are formulated, one for the fibers and one for the matrix. This enables the model to embody the correct values of the intralaminar mode I and II fracture energies of the woven lamina. The model is calibrated using constituent and lamina level test data, and then used to predict the ballistic impact behavior of a single plain-woven lamina under a wide range of projectile impact velocities. The model is demonstrated to predict very well the projectile residual (rebound and exit) velocities, the energy dissipation, the major failure modes of the lamina and the corresponding extent of damage, as well as the ballistic limit and deformation cone wave propagation speeds. The model’s simple, conceptually clear architecture, and computational efficiency represent a major advantage compared to existing damage tensor-based models. The model is also extended to multi-layer thick section woven laminate impact, where the analyses consider both intralaminar and interlaminar failures. The predictions are found to be comparable to those from MAT162, a commercially available material model in LS-Dyna, with much better computational efficiency. Via detailed sensitivity studies, it is demonstrated that the mode I and II intralaminar fracture energies of the lamina are a crucial model input, necessary for accurate predictions of ballistic impact. Not knowing these can introduce significant uncertainty and therefore, their characterization is an absolute must. Finally, the optimal meshing considerations as well as the advantages and limitations of the microplane triad model are discussed.

High-velocity impact experiments and quantitative damage evaluation for finite ultra-high-performance concrete targets

In this work, we aim at improved characterization of target damage occurring as the result of projectile impact against ultra-high-performance concrete (UHPC). For this purpose, we present the results of high-velocity impact experiments with spherical steel projectiles and finite-thickness UHPC targets of approximately 115 MPa compressive cylinder strength in the impact velocity range from approximately 600 m/s to 1500 m/s. The data set obtained from these experiments includes residual projectile velocities as well as qualitative and quantitative information on damage. Quantitative damage information is mainly extracted from digital 3D post mortem targets, which are produced by 3D-scanning. For all damage quantities, a dependence on the impact velocity and the target thickness is discussed and used to provide possible explanations for the origin of the particular type of damage. The large data set presented in this work can constitute the basis for a comprehensive and quantitative verification and validation of analytical, empirical, and numerical models that describe the perforation of UHPC targets in the investigated impact velocity range.

High-speed projectile perforation of nickel-based Inconel 718 superalloy plates: Experiments and modeling

Understanding ballistic behavior of structural materials is important for their applications in aeronautical and astronautical industries. We investigate perforation of 2-mm thick Inconel 718 superalloy plates by spherical stainless steel 304 projectiles with high-speed photography at impact velocities ranging from 548 ms−1 to 1360 ms−1. Postmortem target samples are characterized with optical metallography, scanning electron microscopy and electron backscatter diffraction as regards bullet hole morphology and deformation. Grain refinement and shear banding are the main microstructural deformation modes near the bullet holes. Shear dominated deformation and tension–shear dominated deformation of target material occur sequentially in bullet hole along the impact direction. The morphologies of bullet holes and postmortem projectiles are obtained from the experiments and simulations. The effect of projectile deformation on ballistic behavior of the target is investigated. On the basis of dimensional analysis, a quadratic relation is derived between the energy absorption ratio of target and the dimensionless postmortem projectile diameter, along with a phenomenological model that can well predict projectile residual velocities.

Novel method in the modeling of adiabatic shear bands in ballistic impact: An application on Inconel 718 alloy

The failure mechanism for thick metal plates ballistically impacted by blunt projectiles is known as an Adiabatic Shear Band (ASB), which results in a catastrophic failure due to concentrated shear deformation. ASBs are generally considered to be a material or structural instability and as such are not controllable. ASBs are also a thermodynamic phenomenon occurring at high strain rates and are characterized by large deformations, localized in a narrow band consisting of highly sheared material. Due to the extreme localization of the shear band, it is difficult to model ASBs using the Finite Element Method, because the mesh size needed to capture it is often not practical for real applications.Validated numerical two-dimensional simulations revealed that the tabulated Johnson-Cook (J-C) material model is successful in predicting this mode of failure only using meshes composed of elements with a size that is of the same magnitude order of the ASB width. Because the ASB width of some high-performance metal alloys such as Inconel 718 is on the order of 1 µm, this material model cannot be used in practical applications to predict ASB.This paper describes the enhancements made to the tabulated J-C material model that allow simulations of Adiabatic Shear Band development, under the correct loading conditions, in meshes with element size of practical use in current engineering applications. Full scale impact tests were used to validate the accuracy of the enhanced material model by comparing the ballistic limit, projectile residual velocity, and failure morphology. It is shown that this approach provides a robust and efficient method for simulating Inconel 718 structures under impact, with meshes composed of element of size compatible with modern commonly available computational resources even when the failure mode is an ASB.

Theoretical investigation on energy absorption of single-layer graphene under ballistic impact

The superb mechanical properties make graphene an ideal candidate material for impact protection. Combining molecular dynamics simulations and theoretical analyses, the deformation and failure modes, energy absorption of single-layer graphene under ballistic impact are investigated. According to numerical and theoretical results, the expression for residual velocity of projectile after impact is given. The dependence of deformation and failure modes, energy absorption mechanisms, specific penetration energy (SPE) on impact velocity is analyzed. The results show that during low-velocity impact, there are conical deformation region (CDR), star-like crack and monoatomic carbon chain in graphene. Energy absorption mechanisms of graphene are mainly local deformation and fracture. With increasing impact velocity, the size of CDR decreases. The star-like crack gradually transforms into circular hole. When impact velocity is high enough, carbon atoms within projectile projection area in graphene will be ejected in the form of debris. The kinetic energy (KE) loss of projectile is converted into KE of debris carbon atoms and fracture energy of carbon bonds. Besides, it is also found that SPE (dominant factors are deformation of conical region and KE increments) exhibits a decreasing–increasing trend with increasing impact velocity. When impact velocity is the same, SPE decreases with increasing projectile diameter.

The DISCS method for perforation simulation of thin metallic plates by a rigid projectile

The DISCS method had been developed for penetration analysis of an axisymmetric projectile with a slender nose into a semi-infinite medium. Recently, the authors developed an approximate approach to assess perforation of concrete slabs of finite thickness, using the DISCS method. The present paper extends the approximate model to the perforation analysis of ductile metallic thin plates and determines the key parameters of the projectile residual velocity, the target perforation limit, and the ballistic limit. The present investigation focuses on thin metallic plates, the thickness of which is considerably smaller than that of the concrete slabs and smaller in comparison to the projectile nose length. The method is rather simple, easy to implement and provides a fast solution. An idealized target is characterized by a set of discs of small thickness responding in the plate plane, disregarding the local damage around the penetration ductile hole. The in-plane response of the discs during penetration and perforation of an idealized target are calculated. The Residual Velocity upon perforation of the Idealized Target (RVIT) is lower than the residual velocity of the real plate since it disregards the local damage, hence, the RVIT is the lower bound of the true residual velocity of the real perforated thin plate. Therefore, a positive RVIT for the thin plate with a given thickness indicates right away that the real target will be perforated. Using the RVIT parameter, the proposed DISCS method turns into a series of RVIT-perforation problems of plates with thicknesses that are smaller than the real thickness, to determine the decreasing RVIT with increasing thickness, until the full thickness is considered. The analysis is carried out using the modified (hybrid) DISCS method, that aims at analyzing penetration depth into a thick target. The analysis is based on the theoretical field equations and the constitutive equations of the plate material. The proposed method is based on a theoretical model and on engineering insight. Neither empirical constants nor any calibrations are required. Validation of the proposed method is carried out thorough comparisons with numerous test data on ductile aluminum and steel plates of different thicknesses that are struck by rigid projectiles at different impact velocities. All the comparisons demonstrate very good correspondence between the proposed method predictions and the test data.

Calculation Method of Residual Velocity of Projectile After Penetrating Target Based on Array Threshold Switch

In order to solve the problem that there are few methods to calculate the velocity of projectile behind the target, the accuracy is not high and the adaptability is limited, this paper proposes a method to calculate the residual velocity of projectile after penetrating the target based on array threshold switch; This method has double optimized the structure and algorithm of the original threshold switch, designed an array threshold switch that contains five different thresholds and is independent of each other. The array threshold switch and the corresponding algorithm are used to calculate the velocity behind the projectile target. Simulation results show that this method can accurately calculate the residual velocity of the projectile through the target, greatly improving the calculation accuracy of the original threshold switch.

Performance of reinforced lightweight geopolymer composite panels subjected to windborne debris impacts

Lightweight panels have been widely employed as building envelopes in construction. As a result of the rising demand for environmentally friendly building materials, the authors recently developed a lightweight geopolymer composite (LGC) material and investigated the performance of reinforced LGC panels under static loading. Superior performance of LGC panels as compared to conventional panels such as autoclaved aerated concrete (AAC) panels has been observed, demonstrating their potential applications. During strong winds, building envelopes might be subjected to windborne debris impact, which could threaten residents and facilities and lead to structural failure. To explore the application potentials of LGC panels in strong wind regions, in this study, the performances of LGC panels subjected to windborne debris impact were investigated and compared with those of AAC panels by using a pneumatic cannon testing system. The failure modes and damage levels under different impact scenarios of LGC and AAC panels and their impact resistance capacities were obtained, compared and quantified in terms of the projectile residual velocity, penetration length and opening size. The effects of matrix materials, panel thicknesses, impact locations, reinforcement spacings and projectile impact velocities on their impact resistance performance were analyzed. For comparison, the punching shear capacities of the panels were also quasi-statically tested and analyzed subjected to the same projectile employed in the impact tests.

Projectile Impact on Plain and Reinforced Concrete Slabs

Reinforced concrete is a material frequently used in protective structures and infrastructure exposed to extreme loading. In this study, the ballistic perforation resistance of 100 mm thick plain and reinforced concrete slabs impacted by 20 mm ogive-nose steel projectiles was investigated both experimentally and numerically. Two different reinforcement configurations were used to investigate the effect of rebar diameter and spacing. Concrete with nominal unconfined compressive strength of 75 MPa was used to cast material test specimens and slabs. Ballistic impact tests were performed in a compressed gas gun facility. The mechanical properties of the concrete were found using standardised tests and two-dimensional digital image correlation, and the constitutive relation was described by a modified version of the Holmquist-Johnson-Cook model. Finite element models in LS-DYNA reproduced the projectile residual velocity in good agreement with the experimental results. The primary objective of the study was thus to validate a rather simple constitutive relation intended for large scale numerical simulations of concrete structures exposed to ballistic impact loading, while a secondary objective was to investigate the effect of reinforcement on the ballistic perforation resistance of concrete slabs both experimentally and numerically since the literature is somewhat inconsistent on this matter.

Thickness Equivalent Method of 921A and Q235 Steel Plate Based on the Similarity of Projectile Penetration Residual Velocity

The penetration judgment of the projectile to the target is vital to evaluate its damage ability. Based on the similarity of projectile penetration residual velocity, the thickness equivalent model of plates with different materials is proposed in this paper. Simulation parameters are validated by physical experiments. Then a series of numerical simulations are carried out on 30CrMnSiNi2A projectiles penetrating 921A and Q235 steel target plates. Results show that with the increase of the plate thickness, the projectile residual velocity decays linearly, while the slope depends on the incident velocities. Simultaneously, the residual velocity conforms to a logarithmic growth as the mass of the projectile increases. Finally, the thickness equivalent relationship between 921A and Q235 steel plate is established by using the ratio of the material strength, the incident angle and the projectile shape coefficient. The proposed model can provide a reference to the general projectile penetration analysis.

A new material model for concrete subjected to high rate of loading

This study presents a modified HJC model for simulating the constitutive behaviour of concrete under large strains, high strain rate and high pressure. The original HJC model has been modified by introducing the shear cracking, pore crushing, tensile cracking, and hydrostatic expansion damage models to the yield surface for reproducing the crushing, spalling (crater formed at the front surface), scabbing (crater formed at the rear surface), and radial cracking in the concrete target. The Lode-Angle model has been introduced to describe the yield surface to account for the substantial difference in the shear strength between the tensile and compressive meridians. The strain rate effect has been considered to suitably model the dynamic compressive and tensile strengths. Single element simulations have been performed to substantiate the effect of modifications introduced in the constitutive model. The results of the single element simulation obtained by using the proposed model (MHJC_K&I) have been compared with the results of the two latest modified (MHJC_Kong [1] and MHJC_Liu [2]) models available in the literature. The MHJC_K&I model has described more realistic strength softening under uniaxial compression when compared with the experiment results. Further, the MHJC_K&I model has described accurately the magnitude of tensile strength under uniaxial tension in comparison to the other two models. Under hydrostatic tension, the MHJC_K&I model described the exponential strength softening and the MHJC_Kong model described the linear softening while the MHJC_Liu model had limitation in describing the softening behaviour. The ballistic experiments have also been performed on 100 and 60 mm thick plain concrete targets against 0.4 kg steel projectile at incidence velocities in the range 103–220 m/s. The damage induced in the concrete targets as well as the residual projectile velocities have been obtained. The MHJC_K&I model has been found to effectively reproduce the damage with respect to the size and depth of the crater as well as the radial cracking at the front and rear surfaces of the plain concrete target. The MHJC_Kong and MHJC_Liu models underestimated the size and depth of the crater and described limitations in reproducing the radial cracking. The residual velocities obtained by using the proposed model (MHJC_K&I) have been found to have a good agreement with the actual results.

High-velocity projectile impact resistance of reinforced concrete slabs with ultra-high performance concrete strengthening - A numerical study

This paper adopted numerical simulations to explore the high-velocity projectile impact (HVPI) performance of 180 mm thick reinforced concrete (RC) slabs with ultra-high performance concrete (UHPC) strengthening. Finite-element modelling of the RC slab and UHPC layer subjected to HVPI was firstly performed to verify the numerical model related to the local damage and projectile residual velocity. Then, the slab configuration parameters concerning the steel rebar layer number and grid size in the UHPC layer, the spacing between the RC slab and UHPC layer, and the layout positions of the UHPC layer were investigated to determine the optimal strengthening strategy to resist projectile perforation. The numerical results demonstrated that snugly placing the UHPC layer without steel rebars upon the impact face of the RC slab was the most effective and efficient strengthening strategy. With the optimal slab configuration, the influences resulting from the unconfined compressive strength of UHPC, projectile mass and nose shape on the projectile perforation of UHPC strengthened RC slabs were explored. For each influencing factor, the relations between the projectile residual velocity and UHPC layer thickness were obtained at various projectile striking velocities. In the light of the simulated data, an empirical formula was established to estimate the ballistic limit of the 180 mm thick RC slab with UHPC strengthening..

Experimental and numerical investigation on the ballistic performance of aluminosilicate glass with different nosed projectiles

An experimental-numerical investigation on the ballistic perforation of aluminosilicate glass tiles is presented in this study. A gas gun has been used to launch steel projectiles with assorted nose shapes including flat, spherical, and conical into aluminosilicate glass tiles. It is found that the residual velocity of projectiles and the fragmentation behavior of glass are strongly affected by the shape of the projectile nose. A coupled FEM-SPH numerical model is built to reproduce the ballistic impact behavior of aluminosilicate glass. The Johnson-Holmquist Ⅱ (JH-2) constitutive model is utilized to describe the rate-dependent mechanical behavior of the glass tiles. The glass tile model adopts the transformation of the finite elements into smoothed-particle hydrodynamics (SPH) elements when the failure criterion is met. This numerical method was validated by comparing with quasi-static compression, Brazilian tension, three-point-bending and dynamic SHPB tests data. The ballistic results from the numerical simulations are compared with experimental data showing good performance in predicting the projectile residual speed, glass tile inelastic deformation and fragmentation process. Finally, the effect of projectile deflection angle and tile thickness on the ballistic behavior of glass is investigated via the proposed model numerically.

Protection mechanism of underwater double-hull coated with UHMW-PE subjected to shaped charge

Shaped charge warhead which is widely utilized for underwater weapons has a severe threat to the survivability of naval ships. Therefore, it is of great significance to improve their anti-destructive capability. Three types of loads - shock wave (SW), shaped charge projectile (SCP) and bubble - are generated during the process of shaped charge associated with underwater explosion, which can cause different damage characteristics into double-hull structure. In this paper, these three loads characteristics and their combined damage into double-hull structure are analyzed. Besides, the protection of fiber metal laminates on this structure are discussed. Firstly, Coupled Eulerian-Lagrangian (CEL) is used to simulate the full physical process of double-hull subjected to shaped charge associated with underwater explosion. Secondly, the damage characteristics of double-hull are obtained under the combined damage of the shock wave, shaped charge projectile and bubble. After that, the steel plate/UHMW-PE laminate (Fiber Metal Laminate, FML) is designed according to the equal surface density theory. The blast and penetration resistance of ultra-high molecular weight polyethylene (UHMW-PE) material is analyzed and the optimized FML models are discussed. The results show that a small plastic deformation and hole of the outer and inner plates of the double-hull are generated by the shock wave and the shaped charge projectile, respectively. A large plastic deformation of the outer plate is caused by the subsequent bubble load, which is torn and pulled off. The hole size of plate coated with PE and the residual velocity of projectile reduced by 26.66% and 69.50% compared with those of the steel plate, respectively. Besides, for the coated cases the outer and inner plates is respectively not pulled off and penetrated by projectile. Additionally, it is worth noting that the bubble collapses and cannot cause the secondary damage into double-hull due to the protection of coated PE. It indicates that the PE has a great protection performance of the double-hull subjected to shock wave, bubble and projectile, which can provide a reference for the naval ships protection design.

New method for predicting perforation parameters of a concrete slab target to a penetrating projectile

The present paper investigates the perforation of a projectile through a concrete slab and proposes a new approach for assessing the perforation parameters, including the projectile residual velocity, and the slab perforation and ballistic limits. The new approach is rather simple and easy to implement and provides a fast solution. A new parameter denoted the “pseudo-residual velocity (VP)” is defined and is theoretically calculated. For a given slab thickness H0, the magnitude of VP(H0) is always smaller than the corresponding true residual velocity. The developed approach reduces the determination of the perforation parameters to a sequence of pseudo-perforation problems that are quickly solved using the modified (hybrid) DISCS method, which had been developed for penetration analysis into thick targets, using the constitutive equations of the slab concrete material. In contrary to many other simplified models, the proposed approach is based on a theoretical model and engineering insight and does not require any empirical constants, or calibrations prior to the analysis. Numerous examples compare the proposed approach predictions to test results, covering different types of concrete, slab thicknesses and projectile impact velocities. In all comparisons, very good predictions of the proposed approach are demonstrated.

Mechanism-driven analytical modelling of UHMWPE laminates under ballistic impact

Ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced composite laminates have been widely used to defend against projectiles and fragments. Although the ballistic performance of UHMWPE composites has been extensively characterized both experimentally and numerically, analytical modelling remains a challenge. This study develops a mechanism-based analytical model of UHMWPE cross-ply laminates, with the progressive process of projectile penetration divided into two sequential stages of local failure and bulging deformation: the former is characterized with the strain concentration model under local shock compaction, and the latter is described using a modified membrane stretching model. Compared with existing energy-based models, the current model enables revealing physical mechanisms underlying the deformation/failure processes of UHMWPE laminate subjected to projectile impact, with relevant parameters correlated with material properties. Further, without using any fitting parameter, the proposed analytical model can predict both the ballistic limit and residual projectile velocity. For validation, the model predictions are compared with existing test data, with good agreement achieved for varying projectile mass, projectile size, laminate type, and laminate thickness. It is demonstrated that the maximum strain under a penetrating projectile is controlled by the thickness of un-penetrated laminate and the growth of bulge, and that the longitudinal wave speed and maximum tensile strain in the UHMWPE laminate dictate its ballistic limit.

Numerical study on influence of target thickness on impact response of GFRP composites

Due to rise in threats like ballistic impacts, blast loading and vehicle collision in armored military vehicles, the demand for materials with high strength and enhanced energy absorption capacity has been increased. Applications of Fiber reinforced composites as armor material in military vehicles is being considered as one of the measures to reduce such threats. The focus of this work is to investigate the energy absorption capacity of a GFRP plates subjected to a rigid projectile with blunt-nosed at the intermediate velocity range by using non-linear finite element code LS-DYNA. It has been found that the numerically computed results of ballistic limit velocity and residual velocity, closely resemble the test results reported in the literature. With altering target thickness, it has also been explored how the energy absorption capacity, projectile's residual velocity, ballistic velocity limit and damage mechanism of composite. The numerical results make it evident that the target thicknesses have a significant impact on the target's ballistic resistance and delamination area.