Showing papers on "Ballistic impact published in 2008"

Ballistic Impact of Dry Woven Fabric Composites: A Review

Abstract: weave, architecture, yarn crimp, and the various mechanisms of energy absorption of the fabric, discussed later. To briefly compare various commercial brands of fabrics, Zylon woven fabrics absorb nearly twice the energy per unit areal density specific energy absorbed SEA than both Kevlar and Spectra, when gripped on all four edges, and almost 12 times that of aluminum fuselage skin. The ballistic impact performance of PBO systems is substantially superior to Kevlar 29 systems and marginally better than Kevlar KM2 systems 4. It is reported in Ref. 5 that Spectra fibers are ten times stronger than steel. Previous review work includes a database of early ballistic fabric research by Cunniff 6, and the mechanisms influencing ballistic performance of woven fabrics by Cheeseman and Bogetti 7.

Measurement of Epoxy Resin Tension, Compression, and Shear Stress–Strain Curves over a Wide Range of Strain Rates Using Small Test Specimens

Abstract: The next generation aircraft engines are designed to be lighter and stronger than engines currently in use by using carbon fiber composites. In order to certify these engines, ballistic impact tests and computational analyses must be completed, which will simulate a “blade out” event in a catastrophic engine failure In order to computationally simulate the engine failure, properties of the carbon fiber and resin matrix must be known. When conducting computer simulations using a micromechanics approach, experimental tensile, compressive, and shear data are needed for constitutive modeling of the resin matrix material. The material properties of an Epon E862 epoxy resin will be investigated because it is a commercial 176°C (350°F) cure resin currently being used in these aircraft engines. These properties will be measured using optical measurement techniques. The epoxy specimens will be tested in tension, compression and torsional loadings under various strain rates ranging from 10−5 to 10−1 s−1 and tempera...

The effect of temperature and strain rate on the impact performance of recyclable all-polypropylene composites

Abstract: Highly oriented polypropylene (PP) tapes, with high tensile strength and stiffness achieved by molecular orientation during solid state drawing, are consolidated to create fully recyclable, high performance “all-polypropylene” (all-PP) composites. These composites possess a large processing temperature window (>30 °C) and a high volume fraction of highly oriented PP reinforcement phase (>90%). This large processing window is achieved by using co-extruded, highly drawn PP tapes. This paper investigates the relationship between the impact resistance of all-PP composite laminates based on these highly oriented co-extruded PP tapes, and the temperature and velocity of impact. Unlike isotropic PP, the highly oriented nature of all-PP composites means that a significant influence of glass transition temperature is not observed and so all-PP composites retain high impact energy absorption even at low temperatures. Finally, the ballistic impact resistance of all-PP composites is investigated and compared with current commercial anti-ballistic materials.

Damage evolution and energy absorption of E-glass/polypropylene laminates subjected to ballistic impact

Abstract: High-velocity transverse impact of laminated fiber reinforced composites is of interest in military, marine and structural applications. The overall objective of this work was to investigate the behavior of laminated thermoplastic composites of varying thicknesses under high-velocity impact from an experimental and modeling viewpoint. In order to analyze this problem, a series of ballistic impact tests have been performed on plain weave E-glass/polypropylene (E-glass/PP) composites of different thicknesses using 0.30 and 0.50 caliber right-cylinder shaped projectiles. A gas gun with a sabot stripper mechanism was employed to impact the panels. In order to analyze the perforation mechanisms, ballistic limit and damage evaluation, an explicit three-dimensional finite element code LS-DYNA was used. Material model 162, a progressive failure model based on modified Hashin’s criteria, has been assigned to analyze failure of the laminate. The projectile was modeled using Material model 3 (MAT_PLASTIC_KINEMATIC). The laminates and the projectile were meshed using brick elements with single integration points. The impact velocity ranged from 187 to 332 m s−1. Good agreement between the numerical and experimental results was attained in terms of predicting ballistic limit, delamination and energy absorption of E-glass/PP laminate.

Structures Under Shock and Impact VI

Abstract: KEYNOTE ADDRESSES Blast mitigation technologies: developments and numerical considerations for behavior assessment and design A geometric approach for dynamic buckling of autonomous lumped mass systems under impact. SECTION 1: STRUCTURES UNDER BLAST AND EXPLOSIVE SHOCK Risk analysis of industrial structures due to chemical explosions Shock wave load of window glass plate structure and hypothesis of its failure New architectural forms to reduce the effects of blast waves and fragments on structures Blast-resistant structural steel connections. SECTION 2: BURIED STRUCTURES UNDER EXPLOSIONS Trenching by explosives nearby an existing pipeline: charge size charts Strength analysis of buried pipes under explosive loads Determination of buried structure loads due to blast explosions. SECTION 3: STRUCTURAL CRASHWORTHINESS AND ENERGY ABSORBING SYSTEMS Reusable roadside impact attenuation devices Impact of ice loads on pile structures and deformation Effects of cutouts on static and dynamic behaviour of square aluminium extrusions Crushing of square aluminium extrusions with aluminium foam filler - numerical analyses The effect of induced imperfections on the formation of the first lobe of symmetric progressive buckling of thin-walled square tubes Crashworthiness of foam-cored sandwich panels with GRP inserts. SECTION 4: DYNAMIC BEHAVIOUR OF STRUCTURES Developments in the prediction of dynamic collapse Testing and analysis of elastic-plastic pinned beams under impulsive loading Stress wave effects on the dynamic axial buckling of cylindrical shells under impact Dynamic load factor in composite highway bridges Effects of bulk liquid on the dynamic characteristics of a thin walled cylindrical tank by finite element analysis and experimental modal analysis Numerical analysis of damped oscillations using modified finite integral method. SECTION 5: FULL AND SCALE-MODEL TESTING Testing and simulation of manufacture of metal machine components using exposive welding Development and applications of a new pulse pressure loading test rig Calibration of piezoelectric pressure and acceleration transducers Development of a test facility to simulate pyroshock environments in laboratory. SECTION 6: INTERACTION BETWEEN ANALYTICAL AND EXPERIMENTAL RESEARCH Target strength effects on the predicted threshold velocity for hemi- and ogival-nose penetrators perforating finite aluminium targets Vibrations of viscoplastic plates under impact load Investigation of the buckling of elastic composite rings under internal blast loading EBlast - an emergency blast system expert Orbital debris impacts against spacecraft multiple shields: comparison of hypervelocity experiments and hydrocode simulations Render-safe impact dynamics of the M557 fuze Blast and foreign object damage to plate structures using testing and simulations. SECTION 7: SEISMIC ENGINEERING APPLICATIONS Impact of neighbour building parts in case of earthquake Seismic response of two adjacent non-symmetric multistory buildings The seismic performance of precast columns using high strength concrete and post-inserted main reinforcement Calibration of a numerical model for the simulation of masonry under earthquake loading Extended and localized vibration modes of groups of modular buildings excited by ground motions or blasts. SECTION 8: MATERIAL RESPONSE TO HIGH RATE LOADING - 8.1 COMPOSITE LAMINATES Micromechanics based modeling of damage in composites under high velocity impact - a review Underwater shock wave loading on wood. 8.2 BRITTLE MATERIALS RESPONSE - Modeling of shock and impact behaviours of aluminium oxide A test for the rate effect on concrete fracture energy Effects of strain rate on concrete strength subjected to impact load - Dynamic compressive strength task by Split Hopkinson pressure bar method Dynamic strain softening of concrete in compression under rapid loading Hard impact testing of confined concrete cylinders Issues in the numerical simulation of strain-rate and pressure sensitive cementitious granular materials Advances for modelling of geological materials. 8.3 DEFORMATION AND FRACTURE UNDER IMPACT LOADING - Scaling issues in dynamic fragmentation Impact effect due to pavement irregularities on the dynamic response of bridges Testing with the torsional split Hopkinson bar at strain rates above 10,000 1/s The role of complex microstructures on high rate loading response On predicting and modelling material under impact loading On the use of the symmetric Taylor test to evaluate dynamic ductile compression fracture properties of metals Numerical simulation of composite structures under impact. 8.4 SHOCK WAVE PHENOMENA - ALEGRA - code validation: experiments and simulations Behaviour of a quartzite submitted to a spherical divergent shock-wave: experiments and modelling The influence of the crack tip plastic zone strain hardening on the metal High Cycle Fatigue behaviour A strain history dependent model for concrete High speed metal forming of circular disks and cylindrical tubes in a liquid shock tube. SECTION 9: BEHAVIOUR OF STEEL AND COMPOSITE STRUCTURES Ballistic impact on ceramic/composite armours An experimental set-up used in ballistic penetration The residual life of battle damaged bridges. SECTION 10: BEHAVIOUR OF CONCRETE MATERIAL AND STRUCTURES Testing and evaluation of out-of-plane strength of unreinforced masonry infills Dynamic behaviour of prestressed concrete beams under rapid speed loading 3D dynamic analysis and computer graphics application to impact failure simulation for reinforced concrete slabs Experimental studies on the inelastic behaviour of reinforced concrete panels under high-speed loading: effects of dynamic loading Experimental studies on the inelastic behaviour of reinforced concrete panels under high-speed loading: effects of rebar ratio and lap splices On the concrete material response to explosive loading - numerical simulations Validation of a viscodamage model for the dynamic behaviour of concrete Computed redial stresses in a concrete target penetrated by a steel projectile Modern geopenetrators and relevant revision of concrete penetration models Impulsive loading on reinforced concrete slabs - modelling considerations.

A numerical investigation of the influence of yarn-level finite-element model on energy absorption by a flexible-fabric armour during ballistic impact

Abstract: A series of transient non-linear dynamic finite-element method (FEM) analyses pertaining to the interaction of a single-ply plain-woven balanced square textile-fabric armour with a spherical steel projectile is carried out in order to compare the corresponding results obtained for two different yarn models: (a) a solid FEM model in which the warp and weft yarns are represented using first-order three-dimensional solid elements and (b) a membrane model in which the same yarns are represented using second-order membrane elements. The analyses are carried out under different yarn—yarn and projectile—fabric frictional conditions and under different far-field boundary conditions applied to the edges of the fabric. The results obtained showed that the two sets of analyses yield comparable predictions regarding the temporal evolution and the spatial distribution of the deformation and damage fields within the fabric, regarding the ability of the fabric to absorb the projectile's kinetic energy and regarding the ...

The experimental and analytical characterization of the macromechanical response for triaxial braided composite materials

Abstract: Increasingly, carbon composite structures are being used in aerospace applications. Their highstrength, high-stiffness, and low-weight properties make them good candidates for replacing many aerospace structures currently made of aluminum or steel. Recently, many of the aircraft engine manufacturers have developed new commercial jet engines that will use composite fan cases. Instead of using traditional composite layup techniques, these new fan cases will use a triaxially braided pattern, which improves case performance. The impact characteristics of composite materials for jet engine fan case applications have been an important research topic because Federal regulations require that an engine case be able to contain a blade and blade fragments during an engine blade-out event. Once the impact characteristics of these triaxial braided materials become known, computer models can be developed to simulate a jet engine blade-out event, thus reducing cost and time in the development of these composite jet engine cases. The two main problems that have arisen in this area of research are that the properties for these materials have not been fully determined and computationally efficient computer models, which incorporate much of the microscale deformation and failure mechanisms, are not available. The research reported herein addresses some of the deficiencies present in previous research regarding these triaxial braided composite materials. The current research develops new techniques to accurately quantify the material properties of the triaxial braided composite materials. New test methods are developed for the polymer resin composite constituent and representative composite coupons. These methods expand previous research by using novel specimen designs along with using a noncontact measuring system that is also capable of identifying and quantifying many of the microscale failure mechanisms present in the materials. Finally, using the data gathered, a new hybrid micromacromechanical computer model is created to simulate the behavior of these composite material systems under static and ballistic impact loading using the test data acquired. The model also quantifies the way in which the fiber/matrix interface affects material response under static and impact loading. The results show that the test methods are capable of accurately quantifying the polymer resin under a variety of strain rates and temperature for three loading conditions. The resin strength and stiffness data show a clear rate and temperature dependence. The data also show the hydrostatic stress effects and hysteresis, all of which can be used by researchers developing composite constitutive models for the resins. The results for the composite data reveal noticeable differences in strength, failure strain, and stiffness in the different material systems presented. The investigations into the microscale failure mechanisms provide information about the nature of the different material system behaviors. Finally, the developed computer model predicts composite static strength and stiffness to within 10 percent of the gathered test data and also agrees with composite impact data, where available.

Effect of Microscopic Damage Events on Static and Ballistic Impact Strength of Triaxial Braid Composites

Abstract: In previous work, the ballistic impact resistance of triaxial braided carbon/epoxy composites made with large flat tows (12k and 24k) was examined by impacting 2 X2 X0.125" composite panels with gelatin projectiles. Several high strength, intermediate modulus carbon fibers were used in combination with both untoughened and toughened matrix materials. A wide range of penetration thresholds were measured for the various fiber/matrix combinations. However, there was no clear relationship between the penetration threshold and the properties of the constituents. During some of these experiments high speed cameras were used to view the failure process, and full-field strain measurements were made to determine the strain at the onset of failure. However, these experiments provided only limited insight into the microscopic failure processes responsible for the wide range of impact resistance observed. In order to investigate potential microscopic failure processes in more detail, quasi-static tests were performed in tension, compression, and shear. Full-field strain measurement techniques were used to identify local regions of high strain resulting from microscopic failures. Microscopic failure events near the specimen surface, such as splitting of fiber bundles in surface plies, were easily identified. Subsurface damage, such as fiber fracture or fiber bundle splitting, could be identified by its effect on in-plane surface strains. Subsurface delamination could be detected as an out-of-plane deflection at the surface. Using this data, failure criteria could be established at the fiber tow level for use in analysis. An analytical formulation was developed to allow the microscopic failure criteria to be used in place of macroscopic properties as input to simulations performed using the commercial explicit finite element code, LS-DYNA. The test methods developed to investigate microscopic failure will be presented along with methods for determining local failure criteria that can be used in analysis. Results of simulations performed using LS-DYNA will be presented to illustrate the capabilities and limitations for simulating failure during quasi-static deformation and during ballistic impact of large unit cell size triaxial braid composites.

Lightweight polyethylene non-woven felts for ballistic impact applications: Material characterization

Abstract: The polyethylene non-woven felt, Dyneema Fraglight, has excellent capabilities to stop bomb fragments. According to the manufacturer, a felt with an areal density of 1.2 kg/m2 stops a 17-grain projectile at 450 m/s. The research presented in this paper aims at improving our understanding of how non-woven felts work. Static tensile tests were performed at different strain rates and temperatures. The static tensile tests showed that there is an important size effect: the strength of the specimens decreases when increasing the size of the specimen, for lengths of 5 cm or less. This effect is expected since the felt is made by mixing, combing and needle punching of 5-cm-long fibers. The tests also showed that the felt is anisotropic and that at a temperature of 100 °C it loses a significant part of both its strength and strain to failure. Tensile tests at medium (1 s−1) and high strain rates (1000 s−1) did not show any evidence of strain rate dependence. Out-of-plane punching tests, designed to help with the modeling, were also performed and the results are presented.

Digital ballistic impact detection system

Abstract: Methods and devices for a miniature, ultra-low power impact recorder for detecting, quantifying and recording the energy of an explosive blast or ballistic projectile impact. In one embodiment, the impact recorder can included a sensor comprised of an array of electromechanical resonators that is sensitive to the vibrations produced in selected, discrete frequency ranges that approximate the spectral signature characteristics of the shockwave resulting from the ballistic impact event, even after traveling through impacted material or body tissues.

Preliminary study of ballistic impact on an industrial tank: Projectile velocity decay

Abstract: Since the events of September 11, 2001, the possibility of an intentional act targeting the chemical process industry has become realistic. It is, therefore, a great concern to be able to predict the immediate consequences of such an act. This study is intended to improve our knowledge about the sequence of events that occurs when a high-speed bullet (>1000 m s−1) penetrates a vessel filled with toxic liquid. We find that, prior to liquid ejection, several well-defined phases occur, including the phenomenon known as the “hydraulic ram.” This paper focuses on projectile–target interactions and explains how the decay of projectile velocity is related to the initial conditions of the target.

FAA Development of Reliable Modeling Methodologies for Fan Blade Out Containment Analysis

Abstract: This report summarizes the ballistic impact testing that was conducted to provide validation data for the development of numerical models of blade out events in fabric containment systems. The ballistic impact response of two different fiber materials - Kevlar 49 (E.I. DuPont Nemours and Company) and Zylon AS (Toyobo Co., Ltd.) was studied by firing metal projectiles into dry woven fabric specimens using a gas gun. The shape, mass, orientation and velocity of the projectile were varied and recorded. In most cases the tests were designed such that the projectile would perforate the specimen, allowing measurement of the energy absorbed by the fabric. The results for both Zylon and Kevlar presented here represent a useful set of data for the purposes of establishing and validating numerical models for predicting the response of fabrics under conditions simulating those of a jet engine blade release situations. In addition some useful empirical observations were made regarding the effects of projectile orientation and the relative performance of the different materials.

Ballistic/impact resistant foamed composites and method for their manufacture

Abstract: A foamed composite armor laminate comprising interleaved combinations of ballistic resistant fabrics, and ceramic and/or metallic plates or sheets in a polymeric foam matrix. The foamed composite armor can be fabricated by inserting polymer powder or sheets between layers of fabric and/or ceramic or metallic sheets to form a laminated structure, heating this laminated structure under pressure to form a consolidated panel, and then foaming the polymeric portion of the consolidated panel in an autoclave or pressure vessel by saturating the polymeric portion with inert gas at elevated temperature, rapidly releasing the pressure and controllably cooling the laminated structure to ambient. Alternatively, pre-foamed panels can be laminated to fabric, ceramic and/or metallic sheets using adhesives or the like. Through proper selection of the various elements of the laminate, i.e. the foamed polymer matrix, the polymeric fabric(s) and the ceramic and metallic sheet(s), a wide variety of ballistic, flame retardance, stiffness and other properties can be custom designed into the product for specific end use applications.

Characterization of the deformed microstructure in 1Cr18NiTi stainless steel under ballistic impact

Abstract: Microstructural characteristics of 1Cr18Ni9Ti stainless steel impacted by GCr15 projectiles at a velocity of 2–6 km/s was studied through the optical microscope, SEM, TEM and EBSD techniques. The experimental results show that the adiabatic shear bands beneath the crater are observed, and its width is ranging from 1 to 10 μm. The deformation twins, martensite and intersection between them are observed simultaneously under the crater, which should be attributed to the high strain rate impact. The elongated subgrains with high aspect ratio are found in the shear band, while the melt-related microstructure is observed in the shear band. The heat converted from plastic work continuously increases the local temperature and thus leads to continued softening, even melting, in the material. According to the constitutive equation, the temperature calculated inside a shear band can be rose to the melting point of the material, which explains the melt-related microstructure observed inside shear bands simply.

Influence of Polymer Restraint on Ballistic Performanceof Alumina Ceramic Tiles

Abstract: An experimental study has been carried out to evaluate the influence of confinement ofalumina ceramic tiles through polymer restraint, on its ballistic performance. Tiles of 99.5 per centpurity alumina were subjected to ballistic impact against 7.62 mm armour piercing projectiles atvelocities of about 820 m/s. The tiles of size 75 mm x 75 mm x 7 mm were confined on both facesby effectively bonding varying numbers of layers of polymer fabrics. These were then bondedto a 10 mm thick fibre glass laminate as a backing using epoxy resin. High performance polyethyleneand aramid polymer fabrics were used in the current set of experiments for restraining the tiles.Comparative effects of confinement on energy absorption of tiles with varied number of layersof fabrics were evaluated. It was observed that by providing effective confinement to the tile,energy absorption could be doubled with increase in areal density by about 13 per cent.Photographs of the damage and the effects of restraint on improvement in energy absorptionof ceramic tiles are presented and discussed.

Digital wound detection system

Abstract: Methods and devices for a miniature, ultra-low power impact recorder (24) for detecting, quantifying and recording the energy of an explosive blast or ballistic projectile impact. In one embodiment, the impact recorder can included a sensor (30) comprised of an array (32) of electromechanical resonators (34) that is sensitive to the vibrations produced in selected, discrete frequency ranges that approximate the spectral signature characteristics of the Shockwave resulting from the ballistic impact event (54), even after traveling through impacted material or body tissues.

Analysis of Multi-Layered Materials Under High Velocity Impact Using CTH

Abstract: : Multi-layer armor containing ceramic and metallic layers has become more common in the past two decades. Typically, ceramics have high compressive strength; that feature combined with their low density make them highly desirable for armor applications. This research effort numerically simulates ballistic impact of a cylindrical penetrator with a hemispherical tip on multi-layer metallic and ceramic targets of finite thickness. The projectile is made of S7 tool steel, while the target consists of rolled homogenous armor and boron carbide ceramic. The Eulerian hydrocode CTH, ideal for studying cases of gross global and local deformation, is used to perform an axisymmetric analysis of the projectile and the target. The Johnson-Holmquist constitutive model (JH-2) for brittle materials is used for the ceramic layers, and the Johnson-Cook constitutive model is used for the metallic layers. Various arrangements of ceramic and metallic layers were simulated over a range of velocities to quantitatively determine ballistic limits. Comparison of the ballistic limits for each configuration will determine which ceramic-metal lay-up arrangement is optimal for resisting penetration of the given projectile. This research shows that replacing multiple metallic target layers with B4C ceramic decreases the resistance of the target to the penetration of the projectile for a target of given thickness.

Improved Ballistic Performance by Using a Polymer Matrix Composite Facing on Boron Carbide Armor Tiles

Abstract: Ballistic impact testing was used to compare the performance of boron carbide armor tiles with and without a polymer matrix composite (PMC) facing. This facing layer was in addition to a Spectra Shield Plus® spall cover and backing plate. The armor tiles were tested against a 7.62 mm armor piercing round fired from a universal receiver at varying velocities. Variations in the PMC facing were examined to evaluate the effect on performance. Facing variables included: the type of fiber, the number of plies in the PMC layer, and the orientation of the fibers in the individual plies. The use of a PMC facing improved the ballistic performance by as much as 40% compared to tiles without the facing layers. Although preliminary, these results suggest that the use of a PMC facing is an effective way to improve the ballistic penetration resistance of ceramic armor.

Experimental Characterization of the Impact-Damage Tolerance of a Cross-Ply Graphite-Fiber/Epoxy Laminate

Abstract: In this study, the impact-damage tolerance of a graphite-fiber/epoxy composite laminate is studied by examining the correlation between the impact force and the resulting delamination area in the laminate. The cross-ply [02/902/02]s composite laminate was made of thermosetting P7051S-20Q-1000 prepregs (Toray Composites America). A Hopkinson pressure bar (HPB) was employed to create the impulsive loading with varying magnitude. Transient impact force, displacement, impact power, and transmitted impact energy were calculated using the transient signals recorded from the strain gage mounted on the HPB. Impulsive loads with controllable magnitude were used to induce delamination damage with varying size in the composite samples. Nondestructive evaluation based on a novel ultrasonic pulse-echo reflector technique was used successfully for characterizing the delamination areas in the thin composite samples with thickness ∼2 mm. The present experimental results indicate that there exists a very good linear correlation between the impact force (e.g. the peak force, impact impulse, peak impact power, and the transmitted impact energy of the first impact force pulse exerted by the HPB) and the delamination area of the composite samples. This correlation can be used to determine the threshold of the impact force that initiates the delamination damage in the composite laminate. In contrast to the weight-drop test, the present experimental method successfully examined the impact damage tolerance of polymer matrix composites (PMCs) subjected to impulsive loading with very high force magnitude and ultra short duration such as the typical ballistic impact. The present method and results can be used for the study of impact damage tolerance of PMCs with varying lay-ups and interface modifications. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Explicit Finite Element Analysis of 2024-T3/T351 Aluminum Material under Impact Loading for Airplane Engine Containment and Fragment Shielding

Abstract: Uncontained aircraft engine failure can cause catastrophic damaging effects to aircraft systems if not addressed in the aircraft design. Mitigating the damaging effects of uncontained engine failure and improving the numerical modeling capability of these uncontained engine events are crucial. In this paper, high strain rate material behavior of one of the most extensively used materials in the aircraft industry is simulated and the results are compared against ballistic impact tests. Ballistic limits are evaluated by utilizing explicit finite-element (FE) simulations based on the corresponding ballistic impact experiments performed at different material thicknesses. LS-DYNA is used as a nonlinear explicit dynamics FE code for the simulations. A Johnson–Cook material model with different sets of parameters is employed as a thermo-viscoplastic material model coupled with a nonlinear equation of state and an accumulated damage evaluation algorithm for the numerical simulations. Predictive performance of the...

On the Role of Impact Damage in Armor Ceramic Performance

Abstract: The scientific and engineering prediction of the effective ballistic performance of armor targets is highly desirable to expedite both the development of improved armor ceramics and their incorporation into advanced armor systems. The prediction and assessment of ballistic performance is most often focused on the macro-penetration phenomenon, which is relatively straight forward to observe and measure. Unfortunately, the cognition of the discrete intrinsic material and/or extrinsic target architectural design factors necessary for mitigating and/or controlling the penetration process in notional light-weight passive armor has proven quite elusive. Certainly, it is well known that significant physical damage results from ballistic impact in addition to any projectile penetration. In fact, in armor ceramics, complex internal damage, at both the micro- and the meso/macro-scale, is observed even in the complete absence of any penetration. Furthermore, since such appreciable impact damage occurs prior to the onset of penetration in armor ceramics, the question then needs to be addressed as to what role(s) that existing impact damage would have on the initiation and progression of subsequent penetration. Moreover since the ceramic damage and the penetration processes are both dissipative of kinetic energy transferred from the impacting projectile, the overall ballistic performance of impacted ceramics must be related to both impact damage and penetration. Various issues are raised and discussed relating to the characterization and utilization of actual impact damage in the evaluation of the overall performance of armor ceramics.