Striking Velocity Research Articles

Mechanical response of paperboard to rapid compression

Abstract ZD-tester is a measurement technique for rapid compression in Z-direction. The strain rate of compression of this device is far beyond the ordinary mechanical testing methods applied in papermaking industries. Thus, it provides insights to the material responses which are relevant to industrial applications, e. g. calendaring, printing, etc where the strain rate ranges from hundreds to thousands per second. A physics model that describes the dynamic process of the probe has been developed, where a linear Maxwell model is used to account for the viscoelasticity of paperboard. The simulation has successfully reproduced both the general features and quantitative details of the experiment. The model reveals that the ratio of the elastic modulus to the viscosity modulus of the material governs the amplitude attenuation while the angular frequency of the striking-rebounding cycle depends mainly on the elastic modulus. The dropping height determines the initial striking velocity but has no direct impact on either attenuation or angular frequency. The model and simulation provided interpretations of both experimental observations and dynamic behaviours of the material. With help of simulation, the impacts of the individual parameters, e. g. the Young’s modulus, E, the viscosity modulus, η, and the drop height, H, were also explored.

Analysis and prediction of erosion behavior of short kenaf fiber‐based hybrid composites using response surface method integrated with neural networks

AbstractThere has been a huge demand in industries for the design and development of bio‐degradable and low‐cost wear resistant composite materials since long. In response to this, the present work includes an exhaustive analysis for the solid particle erosion characteristics of a new class of hybrid polyester composites reinforced with a natural fiber (kenaf) and filled with a construction waste (marble dust) in different proportions. The test trials on the composite samples are conducted using a DUCOM high temperature erosion test rig as per ASTM G76. The experimentation and analysis are conducted as per the L30 model of response surface method (RSM). The results revealed that the incorporation of marble dust enhanced the resistance to erosion wear of the fiber‐polyester composites and among the control factors, the contributions of striking velocity and angle of impingement towards the erosion rate are significant. A predictive model working on the concept of neural networks (ANN) is used for the prediction of erosion rates at different levels and combinations of the significant control factors. The mechanisms of erosion loss are identified from the morphologies of the worn surfaces taken using a scanning electron microscope.

Strike Velocity Prediction of Stick Blunt Instruments Based on Backpropagation Neural Network.

To analyze and predict the striking velocity range of stick blunt instruments in different populations, and to provide basic data for the biomechanical analysis of blunt force injuries in forensic identification. Based on the Photron FASTCAM SA3 high-speed camera, Photron FASTCAM Viewer 4.0 and SPSS 26.0 software, the tester's maximum striking velocity of stick blunt instruments and related factors were calculated and analyzed, and inputed to the backpropagation (BP) neural network for training. The trained and verified BP neural network was used as the prediction model. A total of 180 cases were tested and 470 pieces of data were measured. The maximum striking velocity range was 11.30-35.99 m/s. Among them, there were 122 female data, the maximum striking velocity range was 11.63-29.14 m/s; there were 348 male data, the maximum striking velocity range was 20.11-35.99 m/s. The maximum striking velocity of stick blunt instruments increased with the increase of weight and height, but there was no obvious increase trend in the male group; the maximum striking velocity decreased with age, but there was no obvious downward trend in the female group. The maximum striking velocity of stick blunt instruments has no significant correlation with the material and strike posture. The root mean square error (RMSE), the mean absolute error (MAE) and the coefficient of determination (R2) of the prediction results by using BP neural network were 2.16, 1.63 and 0.92, respectively. The prediction model of BP neural network can meet the demand of predicting the maximum striking velocity of different populations.

Computational fluid dynamics and machine learning algorithms analysis of striking particle velocity magnitude, particle diameter, and impact time inside an acinar region of the human lung

Complementing computational fluid dynamics (CFD) simulations with machine learning algorithms is becoming increasingly popular as the combination reduces the computational time of the CFD simulations required for classifying, predicting, or optimizing the impact of geometrical and physical variables of a specific study. The main target of drug delivery studies is indicating the optimum particle diameter for targeting particular locations in the lung to achieve a desired therapeutic effect. In addition, the main goal of molecular dynamics studies is to investigate particle–lung interaction through given particle properties. Therefore, this study combines the two by numerically determining the optimum particle diameter required to obtain an ideal striking velocity magnitude (velocity at the time of striking the alveoli, i.e., deposition by sedimentation/diffusion) and impact time (time from release until deposition) inside an acinar part of the lung. At first, the striking velocity magnitudes and time for impact (two independent properties) of three different particle diameters (0.5, 1.5, and 5 μm) are computed using CFD simulations. Then, machine learning classifiers determine the particle diameter corresponding to these two independent properties. In this study, two cases are compared: A healthy acinus where a surfactant layer covers the inner surface of the alveoli providing low air–liquid surface tension values (10 mN/m), and a diseased acinus where only a water layer covers the surface causing high surface tension values (70 mN/m). In this study, the airflow velocity throughout the breathing cycle corresponds to a person with a respiratory rate of 13 breaths per minute and a volume flow rate of 6 l/min. Accurate machine learning results showed that all three particle diameters attain larger velocities and smaller impact times in a diseased acinus compared to a healthy one. In both cases, the 0.5-μm particles acquire the smallest velocities and longest impact times, while the 1.5-μm particles possess the largest velocities and shortest impact times.

Prediction of Initial and Striking Velocity of Primary Fragments from Cased Spherical Explosive inside Steel Cubical Structure

Usually, energy generated from an explosive’s detonation is transferred partly in the form of the blast impulse and some in the form of the kinetic energy of casing fragments. When detonation occurs in an explosive casing, it breaks the casing into fragments of different weights with varying velocities. The extent of destruction by these energized fragments depends upon the initial velocity they gain after an explosion. The momentum gained by the fragments decides the capability to perforate a barrier or propagate an explosion. A three-dimensional non-linear FEA method is used to model a box-shaped steel structure. This box-shaped structure is subjected to an internal cased explosion for estimating the initial and striking velocities of primary fragments. The effect of varying charge weight and the effect of the sacrificial wall on the initial and striking velocity of fragments via numerical simulations are also carried out. The initial and striking velocity values obtained through simulation are compared with the design guidelines of the code-based approach, and a good agreement is reported.

Inside the coupling of ladybird beetle elytra: elastic setae can facilitate swift deployment.

The ladybird beetle (Coccinella septempunctata) is known for swift deployment of its elytra, an action that requires considerable power. However, actuation by thoracic muscles alone may be insufficient to deploy elytra at high speed because the maximum mechanical power that elytral muscles can produce is only 70% of that required for initiation of deployment. Nevertheless, the elytra open rapidly, within 3 ms in the initial phase, at a maximum angular velocity of 66.49±21.29 rad s-1, rivaling the strike velocity of ant lion (Myrmeleon crudelis) mandibles (65±21 rad s-1). Here, we hypothesize that elytra coupling may function as an energy storage mechanism that facilitates rapid opening by releasing elastic strain energy upon deployment. To test this hypothesis and better understand the biomechanics of elytra deployment, we combined micro-computed tomography and scanning electron microscopy to examine the microstructure of the coupling of paired elytra. We found that two rows of setae on the internal edges of the elytra coupling structure undergo elastic deformation when the elytra are locked together. Kinematics observations and mathematical modeling suggest that the elastic potential energy stored in the compressed setae generates 40% of the power required for deployment of elytra. Our findings broaden insights into how ladybirds actuate elytra opening by a strategy of using both muscles and elastic microstructures, and demonstrate a distributed pattern of actuation that adapts to geometrical constraints in elytra locking.

Kinematic Analyses of Metallic Plate Perforation by Penetrators with Various Nose Geometries

This study analyses kinematics of a metallic plate perforation by a penetrator with truncated ogive nose geometry to find solutions also to blunt, conical, ogive, and hemi-spherical nosed penetrators. Plugging, ductile hole enlargement, dishing, and petal forming failure modes are used in the analyses. Acceleration throughout perforation is calculated by using the related failure mode, analytical model, and the target-penetrator interaction geometry. Depending on the failure model; back lip and front lip formation during ductile hole enlargement, plug formation during plugging, and deflection of target plate during dishing is also analysed. Analyses are based on projectile’s equation of motion, momentum and energy equations, and projectile-target plate interactions. The analyses results for selected cases, with the impact velocity range 215-863 m/s, are compared with the test data. The residual velocity estimation for a strike velocity is close to the related test data with an error of 0.3-2.2 %, except for conical nosed penetrators at impact velocities approaching the ballistic limit velocity

Study on Intrinsic Influence Law of Specimen Size and Loading Speed on Charpy Impact Test.

Charpy impact energy/impact toughness is closely related to external factors such as specimen size. However, when the sample size is small, the linear conversion relationship between the Charpy impact energy of the sub-size and full-size Charpy specimens does not hold; the Charpy impact toughness varies with the size of the specimen and other factors. This indicates that studying the internal influence of external factors on impact energy or impact toughness is the key to accurately understanding and evaluating the toughness and brittleness of materials. In this paper, the effects of strain rate on the flow behavior and the effects of stress triaxiality on the fracture behavior of 30CrMnSiNi2A high-strength steel were investigated using quasi-static smooth bar and notched bar uniaxial tensile tests and Split Hopkinson Tensile Bar (SHTP). Based on the flow behavior and strain rate dependences of the yield behavior, a modified JC model was established to describe the flow behavior and strain rate behavior. Charpy impact tests were simulated using the modified JC model and JC failure model with the determined parameters. Reasonable agreements between the simulation and experimental results have been achieved, and the validity of the model was proved. According to the simulation results, the impact energy was divided into crack initiation energy, crack stability propagation energy and crack instability propagation energy. On this basis, the effects of striker velocity and specimen width on the energy and characteristic load of each part were studied. The results show that each part of the impact energy has a negligible dependence on the hammer velocity, but there is a significantly different positive linear relationship with the width of the sample. The energy increment of each part also showed an inverse correlation with the increase in the sample width. The findings reveal that the internal mechanism of Charpy impact toughness decreases with the increase in sample width; to a certain extent, it also reveals the internal reason why the linear transformation relationship of Charpy impact energy between sub-size specimens and standard specimens is not established when the specimens are small. The analytical method and results presented in this paper can provide a reference for the study of the dynamic behavior of high-strength steel, the relationship between material properties and sample size, and the elastic–plastic impact dynamic design.

Influence of Support Surface Shape of a Stationarily Installed Elastic Valve on the Change in Pre-impact Velocity of Impact Machine Striker

The dynamic contact problem of the interaction between the impact machine striker and a conical annular elastic valve made of elastomer (rubber), which choks the reverse motion chamber in impact machines for mining and construction, is considered. The influence of the shape of the valve support surface on the drop in the pre-shock velocity of the striker during contact interaction is studied. Variants of the shape of the supporting surface of the valve are founded, at which the smallest drop in velocity is observed. For two variants, the dependence of the change in the decrease of the pre-impact velocity with an increase in the elastic properties of the elastomer was obtained. It is proved that with an increase in the elastic properties of the material, the drop in pre-impact velocity increases linearly, and for support surface shape that previously showed a smaller velocity drop, the pre-impact velocity drops less with increasing modulus of elasticity.

Analytical Investigation of Ricochet Range of Ogive—Shaped Nose Projectile Obliquely Penetrating Thick Steel Target

The ricochet phenomenon has been studied worldwide for a long time in consideration of its significance in ballistics. A ricochet projectile has proven to be worthless to its launcher, as warheads fail to penetrate the interior of targets and strike the facilities and personnel of enemies effectively. A large portion of related research has been dedicated to avoiding ricocheting, which mainly focuses on improving the penetration ability of a projectile in order to obtain a better penetration effect, while investigations on the proactive protection of key targets from damage caused by a ricochet projectile are minor. This study analytically explores the ricochet range of a projectile obliquely penetrating a thick steel target. Firstly, the moment of momentum equation of the ricochet projectile based on theoretical mechanics is utilised to analytically calculate its trajectory, where a mathematical model of a two-stage ricochet impacting is established through the geometrical analysis of the ricochet process for determining the ricochet range of a projectile and the size of the bulletproof structure. Then, impact experiments of a projectile obliquely penetrating thick steel targets at different striking velocities and inclination angles are carried out, and the influences of the striking velocity and angle of attack on the damage pattern, area and penetration depth are discussed to identify the ricochet phenomenon. Moreover, the deflection angle of the ricochet projectile is computed, which is compared with the experimental measurements in order to validate the accuracy of this proposed model. This proposed research may promote security protection during live-firing training and provide a theoretical foundation for the optimisation of purposeful protection.

Investigation of the notch depth effect on Charpy fracture energy and fracture surface features of API X65 steel

ABSTRACT Different factors such as notch angle, notch depth, notch root radius, specimen size, hammer geometry and striker velocity affect the value of Charpy impact energy. The aim of present study is to measure the effect of notch depths (in the range from 1.25 to 3 mm) on fracture energy and fracture surface features of API X65 steel plates using Charpy impact tests. For this purpose, 24 specimens were made with 8 different notch depths (3 specimens per notch depth), which were tested to obtain the fracture energy. Furthermore, a computer simulation of the experiment was performed with a three-dimensional model based on Gurson's modified damage law via Abaqus software. The fracture surface morphology was observed using the SEM microscope to evaluate the fracture mechanisms. The experimental results revealed that the relationship between the fracture energy (E) and the notch depth (a) of the Charpy samples for the tested steel was E = 499.65e−0.3501a . Using this equation, the Charpy energy can be determined for this steel for any notch depth with an interpolation error of 3.31%. Fractographic observations indicated that various fracture mechanisms were observed by changing the notch depth, including brittle fracture with the river-like patterns, ductile-brittle fracture, ductile fracture, and fully brittle fracture.

Impact behavior of hybrid-fiber reinforced concrete beams

The impact studies on concrete beams are primarily pertaining to the drop hammer impact, and studies involving projectile impacts on reinforced concrete beams are limited. In this research, the response of hybrid fiber reinforced concrete (HFRC) beams under quasi-static loading and the projectile impact was studied. The HFRC was produced using eight concrete mixes having different proportions and combinations of three fiber types (viz. polypropylene, steel, and Kevlar). The HFRC mixes had a total fiber volume fraction of 1.2% and 1.4%. In addition, plain concrete was used as a control. The beams were tested under the impact of hemispherical nose projectile at varying strike velocities. The projectile strike velocity was increased till the perforation of beams. The main flexural reinforcement in beams was provided on the back face. In order to assess the punching resistance of beams, the beams were tested under quasi-static punching load applied using the same projectile employed in impact tests. The use of hybrid fibers improved beams’ quasi-static punching resistance in terms of energy absorption and load–displacement behavior. The hybrid fibers also improved the impact response of beams by reducing damage levels, increasing perforation velocity, and reducing ejected mass. By modifying the earlier proposed model for slabs, the ballistic limit of HFRC beams is also predicted.

Safety assessment of large-scale all steel LNG storage tanks under wind-borne missile impact

Regarding the disastrous consequences, the large-scale all steel liquefied natural gas (LAS-LNG) storage tank is regulated to be designed to resist the potential impact of wind-borne missiles. This paper aims to study the dynamic response and damage of LAS-LNG storage tanks subjected to the accidental typical wind-borne missile impact. Firstly, six Schedule 40 pipe and flange assembly missiles weigh 36.5 kg were designed according to the specifications of BS 7777 and RG 1.76. Based on the 300 mm-caliber single-stage gas gun, the impact test was conducted with a missile striking velocity of 50 m/s. The local deformation and global response of media-filled steel tanks were assessed experimentally. Then, the commercial finite element (FE) program LS-DYNA was utilized to perform the numerical simulations considering the fluid–structure interactions. The adopted numerical algorithm, constitutive models and the corresponding parameters were validated by comparing with the test data. Finally, based on the validated finite element analyses approach, regarding the design-basis wind-borne missiles specified by the regulatory guide of U.S. Nuclear Regulatory Commission and American Nuclear Society, i.e., RG 1.76, RG 1.221 and ANSI/ANS-2.3-2011, the damage levels of the prototype Chinese Yuhuan LAS-LNG storage tank under wind-borne missile impact were assessed numerically. It indicates that the filled media in the tank would provide additional resistance to the missile impact, the present three design-basis wind-borne missiles could bring certain damage to the outer tank of the Yuhuan LNG storage, but the safety of the inner tank can be guaranteed.

Biomechanical investigation of load differences on the upper extremities in dynamic hand strikes and isometric hand pushes during assembly tasks

AbstractThis study determines the effects of increasing forces on different musculoskeletal load parameters, such as muscle activity and joint movement, during assembly task‐related dynamic hand strikes and isometric push forces. Fifteen subjects (12 men and 3 women) were instructed to strike and push on a force plate in two selected conditions. In the first condition, the palmar surface of the dominant hand is oriented horizontal to the measuring surface; in the second condition, the body position is maintained, but the hand is turned 90° to allow the use of the ulnar side of the hand (fist strike position). The subjects accomplished four force levels in ascending order (i.e., 150, 250, 350, and 400 N) within the corresponding striking and pushing conditions. The extracted kinematic variables of interest were strike velocity, recoil velocity, force plate contact time, peak vertical reaction force component (force plate), force impulse, muscle activity, and maximum joint ranges of motion during the push or strike process. Differences in the results between pushes and strikes and, under certain circumstances, between fist and palm strikes were identified. Increasing push forces correlate with the muscle activity in the pectoralis and lower arm extensor muscles. The fact that, at push forces > 250 N, the subjects modify and adapt their upper body and arm posture to achieve the required force could reveal an obvious feasibility limit and explain why assembly workers tend to use their hands as a hammer.

Experimental and Analytical Study on the Penetration Depth of Mortar Targets Subjected to Projectile Impact in the Hypervelocity Regime

A projectile may be deformed and eroded due to the high pressure generated by hypervelocity penetration, which makes it difficult to describe the penetration mechanism for protection engineering by existing theories at such high velocities. To analyze the penetration depth of concrete-like targets subjected to hypervelocity impact by kinetic energy weapons, experiments with ogive-nosed steel projectiles penetrating mortar targets are conducted, where the average uniaxial compressive strength of the mortar targets is 41.8[Formula: see text]MPa and the impact velocities range from 1[Formula: see text]225[Formula: see text]m/s to 2[Formula: see text]392[Formula: see text]m/s. The experimental results show that the crater diameter and crater depth have a linear relationship with the striking velocity. The depth of penetration (DOP) increases linearly first and then decreases sharply and increases slowly again. Three penetration regimes are observed in turn with increasing velocity, i.e. rigid projectile penetration, abrasive projectile penetration and semifluid projectile penetration. Furthermore, based on a study of the dynamic compression behavior and penetration resistance function of concrete, a hydroelastoplastic-frictional penetration model is established. The velocity range is divided into solid penetration, semifluid penetration and fluid penetration, which correspond to [Formula: see text], [Formula: see text] and [Formula: see text], respectively. Then, the rigid and abrasive projectile penetration models, which consider the projectile mass loss, are verified by the present test data. Finally, the semifluid projectile penetration model is evaluated with the existing test data. These results can provide support for research on the damage effect of hypervelocity kinetic energy weapons and the design of underground strategic protection engineering.

Numerical investigation of the dynamic behavior of a Ti/TiB functionally graded material using Split Hopkinson Pressure Bar test

This work focuses on the mechanical behavior, at high strain rates, of metal-ceramic functionally graded materials (FGMs) using a Split Hopkinson Pressure Bar (SHPB) technique. The validity and the accuracy of the SHPB test results for these composite materials have not been meticulously studied due to their complex mechanical response under dynamic loadings. In this paper, numerical simulations of SHPB tests were performed to determine the dynamic response of specific FGMs at various strain rates. The effects of the compositional gradient exponent and the striker velocity, as well as increasing/decreasing stiffness through the thickness of the functionally graded specimen, were investigated. The considered material is composed of Titanium mono-boride ceramic (TiB) and Titanium metal (Ti) phases; the volume fraction (Vc) of the ceramic constituent varies through-thickness following a power-law distribution. The locally effective material properties were evaluated using a homogenization method based on the self-consistent method (SCM). The elastoplastic behavior of the FGMs under dynamic loading is described using dynamic Tamura-Tomota-Ozawa model (DTTO). The numerical simulations indicated that the compositional gradient exponent and striker velocity have significant effects on the dynamic response of the FGMs. On the other hand, the increasing/decreasing stiffness has a minor effect due to the low thickness of the experimental functionally graded specimen. Finally, the effect of the high strain rates the multiple interface reflection/transmission of the stress wave is very considerable for the design and the optimization of FGMs behavior under dynamic loading.

Design and Optimization of High-Pressure Water Jet for Coal Breaking and Punching Nozzle Considering Structural Parameter Interaction

The technology of increasing coal seam permeability by high-pressure water jet has significant advantages in preventing and controlling gas disasters in low-permeability coal seam. The structural parameters of a nozzle are the key to its jet performance. The majority of the current studies take strike velocity as the evaluation index, and the influence of the interaction between the nozzle’s structural parameters on its jet performance is not fully considered. In practice, strike velocity and strike area will affect gas release in the process of coal breaking and punching. To further optimize the structural parameters of coal breaking and punching nozzle, and improve water jet performance, some crucial parameters such as the contraction angle, outlet divergence angle, and length-to-diameter ratio are selected. Meanwhile, the maximum X-axis velocity and effective Y-axis extension distance are used as evaluation indexes. The effect of each key factor on the water jet performance is analyzed by numerical simulation using the single factor method. The significance and importance effect of each factor and their interaction on the water jet performance are quantitatively analyzed using the orthogonal experiment method. Moreover, three optimal combinations are selected for experimental verification. Results show that with an increase in contraction angle, outlet divergence angle, and length-to-diameter ratio, the maximum X-axis velocity increases initially and decreases thereafter. The Y-direction expansion distance of the jet will be improved significantly with an increase in the outlet divergence angle. Through field experiments, the jet performance of the improved nozzle 3 is the best. After optimization, the coal breaking and punching diameter of the nozzle is increased by 118%, and the punching depth is increased by 17.46%.

Analysis, Design, and Validation of a Vaned Diffuser for Improved Fish Friendliness

Abstract The primary cause of mechanical-related fish injury and mortality in turbomachinery is blade strike. Fish contained in the flow may strike with the rotor blades and the fixed diffuser vanes, the latter being a non-negligible factor causing fish damage in the pump system. In this study, an experiment-based correlation of fish mutilation ratio acts as critical strike velocity. The relation between strike damage in a vaned diffuser and the theoretical pump head is presented as a function of specific speed. As an example, a vaned diffuser is designed for a single-bladed, mixed-flow impeller with the purpose of improving fish friendliness. This pump can be scaled to operate with a head up to 14 m at peak efficiency, without fish damage in the diffuser. Subsequently, experiments are conducted to show the retained pump performance as well as the great improvement of fish friendliness.

Study on the penetration of elliptical cross-section projectiles into concrete targets: theory and experiment

To better understand the penetration mechanism of the elliptical cross-section projectile (ECSP) into semi-infinite concrete target, penetration experiments using three types of ECSPs with different shape ratios (1, 1.25 and 1.61) and with striking velocities ranged from 550 m/s to 1050 m/s were conducted. Penetration depths, penetration trajectory and mass erosion rates of the projectile were obtained after the experiments. The experiment results show that the penetration performance and ballistic stability of the ECSP are equivalent to those of the circular cross-section projectile (CCSP). Based on the theory of complex variable function and conformal transformation, a semi-analytical model which can calculate the cavity boundary stress distribution of elliptical section cavity controlled by the displacement boundary condition was established and the model was validated by comparing the model degenerate solution with Kirsch problem results. Theoretical calculation results show that the radial stress of elliptical section cavity increases progressively from the minor axis to the major axis. In addition, a formula combining with the semi-analytical theoretical model and the local interaction theory was developed. The predicted penetration depths were compared with 30 groups of experiment data with different projectile parameters and striking velocities and coincide quite well with the corresponding experimental data. Finally, the influence of shape ratio and caliber-radius-head (CRH) on the penetration performance of projectile and the application prospect of ECSPs on hypersonic weapon platform were studied.

Strong Upper‐Plate Heterogeneity at the Hikurangi Subduction Margin (North Island, New Zealand) Imaged by Adjoint Tomography

AbstractWe use earthquake‐based adjoint tomography to invert for three‐dimensional structure of the North Island, New Zealand, and the adjacent Hikurangi subduction zone. The study area, having a shallow depth to the plate interface below the North Island, offers a rare opportunity for imaging material properties at an active subduction zone using land‐based measurements. Starting from an initial model derived using ray tomography, we perform iterative model updates using spectral element and adjoint simulations to fit waveforms with periods ranging from 4–30 s. We perform 28 model updates using an L‐BFGS optimization algorithm, improving data fit and introducing P‐ and S‐wave velocity changes of up to ±30%. Resolution analysis using point spread functions show that our measurements are most sensitive to heterogeneities in the upper 30 km. The most striking velocity changes coincide with areas related to the active Hikurangi subduction zone. Lateral velocity structures in the upper 5 km correlate well with New Zealand geology. The inversion reveals increased along‐strike heterogeneity on the margin. In Cook Strait we observe a low‐velocity zone interpreted as deep sedimentary basins. In the central North Island, low‐velocity anomalies are linked to surface geology, and we relate velocity structures at depth to crustal magmatic activity below the Taupō Volcanic Zone. Our velocity model provides more accurate synthetic seismograms with respect to the initial model, better constrains small (50 km), shallow (15 km) and near‐offshore velocity structures, and improves our understanding of volcanic and tectonic structures related to the active Hikurangi subduction zone.