Striking Velocity Research Articles

One-Step Dynamic Calibration of Strain Measurement in a Split Hopkinson Pressure Bar

A new method for dynamic calibration of the bar instrumentation, i.e. the strain measurement, of a split Hopkinson pressure bar is proposed. To this end, the displacements at the bar/specimen interfaces are measured optically and compared with the calculated displacements from the measured strain signals of the bar instrumentation. The bar signals at different positions and the displacements are analyzed by experimental and theoretical approaches. It was found that the additional measurement of the striker velocity and the assumption of momentum conservation can be omitted by applying the new method. Furthermore, there is no need for the conventional two-step calibration, i.e. ‘bars apart’ and ‘bars together’. The proposed one-step dynamic calibration of the instrumentation with respect to strains and displacements can even be performed during an actual test with a specimen. The optical extensometer is not only used for dynamic calibration purposes but also for measuring the interface displacements of the specimen during a test. Consequently, the strains can be calculated from the very beginning of the test.

Numerical evaluation of ballistic limit velocity and experimental ballistic response of 25 mm thick aluminium 7075 alloy targets

The numerical ballistic limit velocity and experimental ballistic response of 25 mm thick AA7075-T651 and solution-treated AA7075 targets were investigated in this paper. In a numerical model, the ballistic limit velocity of 25 mm thick AA7075-T651 and solution-treated AA7075 targets against varied striking velocities in the range of 100–1500 m/s deformable bullets was determined. An experimental ballistic response of 25 mm thick AA7075-T651 and solution-treated AA7075 targets against 7.62 × 51 mm Full Metal Jacket (FMJ) bullets at a high velocity impact of 850 m/s was conducted. Both conditioned targets' tensile, hardness, and impact properties were evaluated. Fracture surface morphology and micrographs of post-ballistic tests were observed using a scanning electron microscope. A numerical model predicted that the optimised ballistic limit velocity of AA7075-T651 and solution-treated AA7075 targets would be 675 and 445 m/s, respectively. Spall fragmentation and the formation of an irregular cavity were observed in AA7075-T651 condition targets, whereas petalling and uniform hole morphology were observed in solution-treated AA7075 condition targets. Experimental ballistic test targets' depth of penetration results show a good correlation with numerically predicted results. A micrograph reveals that there were noticeable changes in the microstructures of solution treated AA7075 condition targets.

MOLECULAR DYNAMICS OBSERVATION OF DISCRETENESS OF THE MASS DISTRIBUTION DURING NANOSCALE FRAGMENTATION

Molecular dynamics simulations of the rigid-anvil collision test are performed by using a two-dimensional computational setup that mimics the traditional ballistic Taylor test. In this extensively utilized computational setup, the slender nanoscale projectiles collide with a rigid wall with hypersonic striking velocities ranging from 3 km/s to 30 km/s. The projectiles used in these simulations are flat-ended, monocrystalline, nanoscale bars prepared at zero temperature. The Poisson hyper-exponential distribution with the logarithmic binning is used to capture the fragment mass (size) distribution under the constraint of the relatively small specimen size 15×100 nm. The objective is to highlight the occurrence of certain discreteness of the fragment mass distribution observed both in time (during the fragment debris evolution) and across the striking velocity field (for the final fragmentation states that correspond to the stationary distributions).

Mechanically excellent nacre-inspired protective steel-concrete composite against hypervelocity impacts

Steel–concrete (SC) composite widely used in military defensive project is due to its impressive mechanical properties, long-lived service, and low cost. However, the growing use of hypervelocity kinetic weapons in the present war puts forward higher requirements for the anti-explosion and penetration performance of military protection engineering. Here, inspired by the special ‘brick-and-mortar’ (BM) structural feature of natural nacre, we successfully construct a nacre-inspired steel–concrete (NISC) engineering composite with 2510 kg/m3, possessing nacre-like lamellar architecture via a bottom-up assembling technique. The NISC engineering composite exhibits nacreous BM structural similarity, high compressive strength of 68.5 MPa, compress modulus of 42.0 GPa, Mohs hardness of 5.5, Young’s modulus of 41.5 GPa, and shear modulus of 18.4 GPa, higher than pure concrete. More interestingly, the hypervelocity impact tests reveal the penetration capability of our NISC target material is obviously stronger than that of pure concrete, enhanced up to about 46.8% at the striking velocity of 1 km/s and approximately 30.9% at the striking velocity of 2 km/s, respectively, by examining the damages of targets, the trajectories, penetration depths, and residual projectiles. This mechanically integrated enhancement can be attributed to the nacre-like BM structural architecture derived from assembling the special steel-bar array frame-reinforced concrete platelets. This study highlights a key role of nacre-like structure design in promoting the enhanced hypervelocity impact resistance of steel–concrete composites.

A parametric study on the high-velocity projectile impact resistance of UHPC using the modified K&C model

This paper presents a comprehensive parametric study on the influence of various aspects on the depth of penetration (DOP) and equivalent crater diameter (ECD) of ultra-high performance concrete (UHPC) caused by high-velocity projectile impact (HVPI) using a modified K&C model. Parameters selected for the investigation include the material properties of UHPC (compressive strength, tensile strength, toughness, elastic modulus, density and dynamic increase factor (DIF)), specimen dimensions (thickness and width), and test conditions (projectile nose shape and striking velocity). Within the range of the investigated material parameters of UHPC, the compressive strength and DIF under compression are the most influential ones for the DOP, while the tensile strength and DIF under tension have the greatest influence on the ECD. It was also found that the Li-Chen equation outperforms other commonly used equations in predicting the DOP of UHPC subjected to HVPI. The findings of this paper facilitate the understanding on the key parameters dictating the resistance of UHPC subjected to HVPI, which shed light on the optimization of UHPC mixture design for the applications in protective structures.

Study of dynamic breakdown of inerter and the improved design

Inerter is a two-terminal dynamic element applied in vibration control systems. Based on the analogy between mechanical and electrical systems, an inerter corresponds to a capacitor. There is an electrical breakdown of a capacitor in electrical systems and there should also be a dynamic breakdown of an inerter in mechanical systems. This study focuses on the dynamic breakdown of an inerter. First, the definition and the expressive form of the dynamic breakdown of the inerter are introduced. The definition of the dynamic breakdown of an inerter in this study is that “the two terminals of the inerter come into contact”. When dynamic breakdown occurs, two terminals of the inerter impact on each other. To analyze the impact when the dynamic breakdown appears, a dynamic model is built. The expression of the impulse when the dynamic breakdown occurs is obtained, and an experimental system is established. Because of the experimental data collected by the force sensor, the impact force is far larger than the weight of the falling parts of the inerter. A design parameter for the inerter, the maximum allowable relative striking velocity, is proposed. Furthermore, the impact forces of the improved design, a new ball-screw inerter with mechanical diodes, are apparently reduced. The relationship between the impact force of the original inerter and the impact force of the improved design is also obtained and verified with experiments. It is concluded that there is a dynamic breakdown of the inerter and that the improved design of the inerter is effective to reduce the impact force when dynamic breakdown of the inerter occurs.

Adjoint‐State Traveltime Tomography for Azimuthally Anisotropic Media and Insight Into the Crustal Structure of Central California Near Parkfield

AbstractSeismic anisotropy provides crucial information on the stress state and geodynamic processes inside the Earth. We develop a novel adjoint‐state traveltime tomography method using P‐wave traveltime data to simultaneously determine velocity heterogeneity and azimuthal anisotropy of the subsurface. First, an anisotropic eikonal equation is derived to model first‐arrival traveltimes in azimuthally anisotropic media. Traveltime tomography is then formulated as an optimization problem constrained by the anisotropic eikonal equation, which is subsequently solved by the adjoint‐state method. Ray tracing is not required. Its high accuracy is achieved by solving the anisotropic eikonal equation and the associated adjoint equation with efficient numerical solvers. In addition, an eikonal equation‐based earthquake location method for azimuthally anisotropic media is developed to solve the coupled hypocenter‐velocity problem. The tomography and earthquake location methods are applied to central California near Parkfield to test their performance in practice. A total of 1,068,850 first P‐wave traveltimes clearly maps the velocity heterogeneity and azimuthal anisotropy in the upper and middle crust. The average P‐wave velocity model shows a striking velocity contrast across the San Andreas Fault (SAF). In the upper crust, we find structural anisotropy in the SAF zone and stress‐induced anisotropy off the SAF zone. In the middle crust, the fast P‐wave velocity directions are generally fault‐parallel due to the decreased effect of the maximum horizontal compressive stress. In all, the real‐data application suggests that the new adjoint‐state traveltime tomography method can be reliably used to investigate anisotropic seismic structures.

Expertise- and Tempo-Related Performance Differences in Unimanual Drumming.

High-speed drumming requires precise control over the timing, velocity, and magnitude of striking movements. To examine effects of tempo and expertise on unaccented repetitive drumming performance using 3D motion capture. Expert and amateur drummers performed unimanual, unaccented, repetitive drum strikes, using their dominant right hand, at five different tempi. Performance was examined with regard to timing variability, striking velocity variability, the ability to match the prescribed tempo, and additional variables. Permutated multivariate analysis of variance (PERMANOVA) revealed significant main effects of tempo (p < .001) and expertise (p <.001) on timing variability and striking velocity variability; low timing variability and low striking velocity variability were associated with low/medium tempo as well as with increased expertise. Individually, improved precision appeared across an optimum tempo range. Precision was poorest at maximum tempo (400 hits per minute) for precision variables. Expert drummers demonstrated greater precision and consistency than amateurs. Findings indicate an optimum tempo range that extends with increased expertise.

A physical model of mantis shrimp for exploring the dynamics of ultrafast systems

Efficient and effective generation of high-acceleration movement in biology requires a process to control energy flow and amplify mechanical power from power density-limited muscle. Until recently, this ability was exclusive to ultrafast, small organisms, and this process was largely ascribed to the high mechanical power density of small elastic recoil mechanisms. In several ultrafast organisms, linkages suddenly initiate rotation when they overcenter and reverse torque; this process mediates the release of stored elastic energy and enhances the mechanical power output of extremely fast, spring-actuated systems. Here we report the discovery of linkage dynamics and geometric latching that reveals how organisms and synthetic systems generate extremely high-acceleration, short-duration movements. Through synergistic analyses of mantis shrimp strikes, a synthetic mantis shrimp robot, and a dynamic mathematical model, we discover that linkages can exhibit distinct dynamic phases that control energy transfer from stored elastic energy to ultrafast movement. These design principles are embodied in a 1.5-g mantis shrimp scale mechanism capable of striking velocities over 26 m [Formula: see text] in air and 5 m [Formula: see text] in water. The physical, mathematical, and biological datasets establish latching mechanics with four temporal phases and identify a nondimensional performance metric to analyze potential energy transfer. These temporal phases enable control of an extreme cascade of mechanical power amplification. Linkage dynamics and temporal phase characteristics are easily adjusted through linkage design in robotic and mathematical systems and provide a framework to understand the function of linkages and latches in biological systems.

RESEARCH ON MECHANISM AND MODEL OF PENETRATION INTO METALLIC THICK TARGET FINITE IN RADIAL EXTENT BY RIGID PROJECTILE

Based on the unified strength theory, considering the effect of intermediate principal stress and lateral free boundary of target to analyze the elastic-plastic stage and plastic stage of the linear strain-hardening target material, analytical solutions of radial pressure on the cavity wall are obtained and the unified penetration model of the linear strain-hardening target material is built. On this basis, resistance formulas and penetration depth formulas of the rigid projectiles with medium-low speed (v0≤1000 m/s) penetrating into metallic thick target finite in radial extent are deduced, then their solutions are obtained by utilizing the Simpson method. Meanwhile, influencing factors for ballistic terminal effects including strength criterion difference are analyzed. The results indicate that the proposed computing method can precisely describe the dynamic responses of projectiles and targets during the whole penetration process. Through this method, a series of different criteria-based analytical solutions are obtained and the ranges of penetration depth of targets under different striking velocities are predicted effectively. Moreover, various parameters have influences on the anti-penetration performance of the target, such as the strength parameter, the striking velocity, the target radius and the shape of the projectile nose; among them the penetration depth has increased by 22.45% as the strength parameter value changes from 1 to 0. In addition, as the ratio of target radius to projectile becomes smaller, the penetration depth becomes bigger, and it has increased significantly when this ratio is less than or equal to 16. It is indicated that the penetration depth is obviously affected by the target boundary size at this time, and it cannot be calculated as an unlimited-size target any more.

The evolution of drum modes with strike intensity: Analysis and synthesis using the discrete cosine transform

The synthesis of convincing acoustic drum sounds remains an open problem. In this paper, a method for analysing and synthesising pitch glide in drums is proposed, whereby the discrete cosine transform (DCT) of an unwindowed drum sound is modelled. This is an extension of the scheme initially proposed by Kirby and Sandler [(2020). Proceedings of the 23rd International Conference on Digital Audio Effects, Vienna, Austria, pp. 155-162], which was able to reproduce key components of drum sounds accurately enough that they could not be distinguished from the reference samples. Here, drum modes were analysed in greater detail for a tom-tom struck at 67 different intensities to investigate their evolution with strike velocity. A clear evolution was observed in the DCT features, and interpolation was used to synthesise the modes of intermediate velocity. These synthesised modes were evaluated objectively through null testing, which showed that a continuous blending of strike velocities could be achieved throughout the data set. An AB listening test was also performed, where 20 participants attempted to distinguish between pairs of real and synthesised sounds. Exactly 50% accuracy was achieved overall, which demonstrates that the synthesised samples were deemed to sound as realistic as genuine samples. These results demonstrate that the DCT representation is a valuable framework for analysis and synthesis of drum sounds. It is also likely that this approach could be applied to other instruments.

Perforation of laminated glass: An experimental and numerical study

Laminated glass is a type of safety glass that is frequently used in blast-resistant windows and bullet-proof glazing. However, few studies concerning the perforation resistance of laminated glass exist in the open literature. In this study, double-laminated glass plates are impacted by 7.62 mm armour piercing (AP) bullets, and their ballistic limit velocity and curve are determined both through experimental tests and numerical simulations. Two different configurations, i.e., a single pane configuration and a configuration of two panes stacked with an airgap in between, are tested at striking velocities between 375 and 700 m/s. The experimental tests showed that the amount of cracking can be divided into three distinct zones and that the extent of these zones is dependent on the striking velocity. In the numerical study, finite element simulations employing higher order elements and 3D node splitting are used to predict the velocity-time history of the bullets during impact. The simulations employ simplified material and fracture models for the glass and PVB. Even so, the numerical predictions are found to be in excellent agreement with the experimental data, and both the residual and ballistic limit velocities are precisely determined.

Ballistic penetration simulation of a 3D woven fabric using high strain-rate dependent yarn model

3D woven fabric has great application potential in military armor systems. Here we report numerical simulation of 3 D angle interlock woven fabric(3DAWF) subjected to the ballistic impact using LS-DYNA. We employed membrane elements to construct the mesoscale yarn-level 3DAWF model to improve computational efficiencies and accuracy. The simplified Johnson-Cook (SJC) material model was proposed for simulating yarns' dynamic behaviors under high-speed impact loadings. The SJC material model and commonly used strain-rate dependent material model Cowper-Symonds (CS) were taken into the FEA model to simulate the fabric's ballistic impact behaviors separately. The ballistic impact tests of 3DAWF subjected to the Full Metal Jacket (FMJ) projectile under the strike velocity 190 ∼ 320 m/s were carried out to validate the new material model. Comparing the results between the tests and theoretical model found that the FEA model using the SJC material model can accurately predict projectile's residual velocities and fabric's deformation and damages. The numerical model using SJC yarn constitutive models can precisely capture the impact mechanism of 3DAWF.

Tail Autotomy Alters Prey Capture Performance and Kinematics, but not Success, in Banded Geckos.

Tails are versatile structures with diverse forms and functions across vertebrates. They are involved in almost all behaviors critical to survival including locomotion, feeding, and predator avoidance. Although the tail's role in locomotion and stability has been widely studied, its role in prey capture is relatively unknown. Lizards are an ideal system to examine the tail's impact on prey capture as most are capable of autotomizing, or dropping, their tail in response to predation and intraspecific competition. Tail autotomy can lower reproduction, decrease locomotor performance, impart instability during jumping, and decrease social status. Desert banded geckos (Coleonyx variegatus) frequently capture evasive prey in nature and appear to use their tail during strikes. However, it is unclear if these tail movements are important for the strike itself, or if they simply draw attention to that part of the body. We used high-speed 3D videography to quantify prey capture performance and kinematics of C. variegatus striking at crickets before and after total caudal autotomy. Trials were conducted within 2 h of autotomy and then repeatedly over a 2-week period. Overall, prey capture success was unaffected by caudal autotomy. However, maximum strike velocity decreased significantly after autotomy, highlighting the importance of the tail during prey capture. Strike kinematics were altered after autotomy in several ways, including geckos adopting a more sprawled posture. Maximum pectoral girdle and mid-back height were significantly lower during post-autotomy strikes, whereas maximum pelvic girdle height was unaffected. However, individual variation was considerable. This downward pitching of the body after tail loss suggests that the tail is necessary for counterbalancing the anterior portion of the body and resisting the rotational inertia incurred after pushing off with the hindlimbs. Utilizing autotomy to test tail function in prey capture can provide valuable insight into how the tail is used in terrestrial predation across a wide variety of species and ecological niches.

Projectile impact resistance of fibre-reinforced geopolymer-based ultra-high performance concrete (G-UHPC)

This paper describes the mix design of geopolymer-based ultra-high performance concrete (G-UHPC) with the compressive strength from 100 to 150 MPa. Projectile impact tests at two striking velocities of ~550 m/s and ~800 m/s were then performed to explore the impact resistance of G-UHPC targets. G-UHPC without the addition of fibres yielded better impact resistance than Ordinary Portland Cement (OPC) concrete regarding crater damage and crack propagation, but inferior performance on reducing depth of penetration (DOP). The addition of fibres in G-UHPC effectively helped reduced DOP, crater damage and crack propagation. Steel fibres with a length of 10 mm and a volumetric fraction of 2% were most effective in resisting projectile impact compared with other G-UHPC specimens. To further comprehend the projectile impact performance of G-UHPC, a calibrated Karagozian and Case Concrete (KCC) model accounting for the strain rate effect was successfully used for G-UHPC in projectile analysis. Numerical results including single element and full-scale quasi-static tests, deceleration-time histories of projectiles during penetration and DOP of G-UHPC targets were obtained to validate the numerical models. After that, trendlines were regressed to predict DOP of G-UHPC at two striking velocities of ~550 m/s and ~800 m/s. Perforation limits of G-UHPC were also proposed for the design of both safe and cost-effective protective structures against projectile impact, in which the perforation limits of G-UHPC were taken as 1.1 times of DOP.

Is There Always a Need for Speed? Testing for Differences in the Striking Behavior of Western Ratsnakes (Pantherophis obsoletus) When Encountering Predators and Prey

Prior to both offensive and defensive striking, snakes can display notable differences in prestrike behaviors between offensive and defensive contexts. However, few studies have investigated strike movements during the different scenarios with which snakes are faced. To better understand how snakes strike, we measured the strikes of Western Ratsnakes (Pantherophis obsoletus; N = 11) presented with two different targets: one simulated predator (a gloved human hand) and one prey (pre-killed mice). For each strike, we recorded strike distance, duration, velocity (average and peak), acceleration (average and peak), and time to start mouth gape. In both encounters, ratsnakes displayed similar time to the initiation of a mouth gape while all peak performances were significantly different between strike types with performances being higher in defensive strikes. Defensive strikes took longer (mean = 122 ± 13 ms), reached greater distances (mean = 15.1 ± 1.7 cm), had higher maximum velocities (mean = 1.80 ± 0.11 ms-1), and maximum accelerations (mean = 101.4 ± 15.2 ms-2). Offensive strikes had much shorter durations (mean = 49 ± 5 ms), distances (mean = 4.3 ± 0.6 cm), maximum velocities (mean = 1.06 ± 0.10 ms-1), and maximum accelerations (mean = 81.4 ± 18.9 ms-2). The results for average performance measurements are similar to those for the maximum performance comparisons. Our results show that snakes can recognize and differentiate prey from threats and respond differently in each situation. Our results also show that predatory and defensive strikes are quantitatively and situationally distinct, should be treated as separate behaviors, and therefore should be evaluated and analyzed separately from one another.

Investigation on the penetration of jacketed rods with striking velocities of 0.9–3.3 km/s into semi-infinite targets

In this study, a combined experimental, numerical and theoretical investigation is conducted on the penetration of semi-infinite 4340 steel targets by a homogeneous 93W rod and two types of jacketed rods with striking velocities of 0.9–3.3 km/s. The results show that the jacketed rods produced typical “co-erosion” damage at all test velocities, except for the 93W/1060Al jacketed rod, which switched from an early “bi-erosion” damage to later “co-erosion” damage at a striking velocity of 936 m/s. However, the homogeneous 93W rod always forms a large mushroom head during the penetration process. The damage mechanisms of these two types of jacketed rods differ for striking velocities of 0.9–2.0 km/s, but this difference gradually decreases with increased striking velocity. For velocities of 2.0–3.3 km/s, all three types of projectiles exhibit typical hydrodynamic penetration characteristics, and the damage mechanisms of the two types of jacketed rods are almost identical. For the same initial kinetic energy, the penetration performance of the jacketed rods is distinctly superior to that of the homogeneous 93W rods. Compared with jacket density, jacket strength shows a more significant influence on the damage mechanism and penetration performance of the jacketed rod. Finally, an existing theoretical prediction model of the penetration depth of jacketed rods on semi-infinite targets in the co-erosion mode is modified. It transpires that—in terms of penetration depth—the modified theoretical model is in good agreement with the experimental and numerical observations for 93W/TC4 and 93W/1060Al jacketed rods penetrating semi-infinite 4340 steel targets.

Parametric Analysis for Erosion Wear of Waste Marble Dust-Filled Polyester Using Response Surface Method and Neural Networks

In this research, the erosion wear characterization of waste marble dust (an industrial/construction waste)-filled polyester composites is evaluated. The relative effect of the control factors on the erosion rate of the composites is experimentally and statistically evaluated using a statistical model based on the response surface method, and the mechanisms of erosion loss are studied from the worn surface morphologies taken using a scanning electron microscope. The analysis reveals that striking velocity, filler concentration, and impingement angle in that sequence are the significant control factors affecting the erosion rate of the composites. The erosion efficiency of the composites is calculated to ascertain the erosion behavior of the composites. Further, an analytical as well as predictive model working on neural networks, is used to predict the erosion rate of the composites at different levels of the individual control factors. Such composites are expected to be advantageous in wear-related applications.

New focal mechanisms reveal fragmentation and active subduction of the Antalya slab in the Eastern Mediterranean

In the Eastern Mediterranean, the convergence of Nubia and Eurasia is accommodated along the Hellenic and Cyprus Trenches. The plate geometry and mode of convergence to the east of the Hellenic Trench remains poorly understood. Specifically, along the west of Cyprus, tomography models reveal NW striking high velocity anomaly, which is interpreted as a slab named as the Antalya slab. However, near surface observations pertaining to the top 15 km of the convergence zone show no evidence of an active subduction in the region. In this study, we investigate the seismic activity along the Antalya slab in order to constrain the mode of convergence and the geometry along this plate boundary. Towards this end, we obtain a new focal mechanism catalogue with reliable centroid depths for earthquakes Mw > 4 from regional waveforms by using path dependent seismic velocity models. Our results indicate that the subduction is still active along the plate boundary segment between Cyprus and Anaximander seamount. The earthquakes along the slab interface reveal a NE-dipping slab with a dip angle of ~35°. Slip vectors show a pure convergent motion which is consistent with relative motion of Anatolia with respect to Nubia. We also identify a number of intraslab earthquakes down to a depth of 120 km along the Antalya slab. The T-axis of intraslab earthquakes show down-dip extension consistent with negatively buoyant subducting slab. The Paphos fault bounds the Antalya slab to the east where previously large right-lateral earthquakes occurred, which marks the relative motion of the Antalya slab with respect to the eastern Cyprus slab. Based on slab isodepth contours of the slab interface, we calculate ~100 km offset between the 80 km depth contours of the Antalya and Cyprus slabs. The western boundary of the Antalya slab possibly lies between the Anaximander and Anaximenes seamounts, where several left-lateral earthquakes are obtained. The western boundary of the Antalya slab can also be identified from orientation change of normal fault earthquakes along overriding plate which shows the limit of N-S extension due to roll-back of the neighboring Hellenic slab.

Numerical simulation of AA7075 under high strain rate with different shape of striker of split Hopkinson Pressure bar

The high strain rate characterization of materials have always remained an essential to know the exact behaviour in dynamic conditions, such as blasts, earthquakes, projectile penetrations, crashworthiness of vehicles, bullet proof armours. These high strain rate characterizations can be done using experimental technique such as Split Hopkinson Pressure Bar (SHPB) Test. These experimental techniques are very costly and difficult to conduct. However, the behaviour of materials under dynamic loading can be performed under high strain rate using finite element simulation of SHPB Test. The numerical simulations of AA7075 under different shape and velocity of striker in dynamic conditions are performed utilizing ABAQUS/Explicit 6.14. To understand the effect of shape, striker bar’s shape is varying from circular to square while its length is kept constant as 200 mm. Furthermore, impact velocity is also varied from 20 to 50 m/s to see the effect of velocity under large strain rates. The test specimen’s shapes are also of varying cross-section to understand the effect of shape of specimen under dynamic conditions. Results stated that the wave’s amplitude and duration are dependent to the striker parameters. Specimen shape also affects the flow behaviour of specimen.