bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of mechanical response of head structure with different brain material models under impact
Authors: Haitao LU , Weibing LI , Qinglei DU 
Published: December 2024

Abstract
Brian material models and mechanical properties are very important for pressure evolution experiments and numerical simulations in head structure under impact. A simplified head structure with core-shell finite element model was established, and the motion, skull stress, skull deformation, and brain stress were numerically simulated with different soft tissue material models. The equivalence of the material model in stress propagation simulation was discussed. In the present work, it showed that when the head with impact velocity of 1m/s, the head structure rebound with a velocity of 0.6 m/s ∼ 0.8m/s, and occurred between 600μs and 1000μs due to different material models, at this time, the stress wave oscillation propagated in the skull underwent 3-5 repeated loads. The positive pressure on the impact side of brain tissue could reach 400kPa ∼ 800kPa, the negative pressure on the opposite side was between −150 kPa to −385kPa, the skull strain was between −1.8 ‰ to −3.7 ‰, and the skull stress was between 25.3MPa ∼ 41.2MPa. In a larger range of impact velocities, material models with strain rate effect have more advantages in stress wave transmission and pressure changing within the core-shell structure. The strain rate effect characterized only by creep and relaxation has limited effects on impact simulation, and directly introducing different strain rate mechanical property interpolation for hyperelastic model simulation is more effective.
A constitutive model for brittle rock subjected to dynamic loadings
Authors: Bai Z , Hu Y T , Li X , Yao H 
Published: December 2024

Abstract
The constitutive model of rock serves as the foundation for researching its mechanical responses under impact and explosion loads, and holds significant academic value and military significance. With the help of the basic solution to Eshelby’s matrix-inclusion problem and meso-damage mechanics, a new constitutive model was developed to describe the dynamic behaviour of brittle rock subjected to impact loadings. Brittle rock was considered here as heterogeneous solids composed of elastic solid matrix and imbedded penny-shaped microcracks. A rate-dependent constitutive relation, considering meso-structural damage mechanism of brittle rock, was derived based on the Ponte-Castaneda and Willis method. Further, micro-damage evolution equations with clear physical concept and fewer parameters were presented. In order to illustrate the predictive ability of the proposed model, comparisons are performed between the model predictions and experimental data from Split Hopkinson pressure bar tests on sandstone. The results show a generally good agreement, thus verifying its rationality and practicability.
The penetration crater characteristics of thick steel plate impacted by tungsten alloy projectiles
Authors: Cui Xin-yu , Luo Zi-qi , Huang Guang-yan , Hu Wen-long , Shi Xin-yi 
Published: December 2024

Abstract
The mild steel target plates impacted vertically by tungsten spherical projectiles with different initial velocities and projectile diameters were studied by ballistic experiments and numerical simulation. The macroscopic properties of the penetration crater were analyzed by the depth, diameter, and overall shape of the crater. The results show that crater diameter and depth increase as initial velocity or projectile diameter increases. With the increase in velocity, the deformation and erosion of tungsten projectiles significantly increased. Specific kinetic energy is used to normalize the velocity and size of the projectile, the expression of crater depth and diameter varying with specific kinetic energy is given, which accuracy R2 is 0.8. Based on THOR theory and experimental data, the accurate calculation model of penetration depth versus projectile mass, initial velocity, and the area of the contact was obtained, with an accuracy of R2 of 0.97.
Research and simulation study on the penetration behavior of Φ 30 mm armor-piercing bullets penetrating armored steel
Authors: Xuan Zhou , Rui Zhu , Ma Minghui , Gao Guangfa 
Published: December 2024

Abstract
To study the penetration behavior and ballistic characteristics of a Φ30mm tungsten alloy armor-piercing projectile penetrating homogeneous armor steel, penetration tests were conducted, and the penetration process was numerically simulated using LS-DYNA. The experimental results show that the presence of the conical section of the Φ30mm armor-piercing projectile forms a “saddle” shaped crater feature. The simulation results indicate that the penetration efficiency of the projectile and the incident velocity exhibit a quadratic function relationship. In the velocity range of 800-1200m/s, the kinetic energy consumed by the projectile for the same penetration depth is essentially the same, i.e., the lateral crater diameter is consistent at different speeds. Additionally, during the penetration process, the penetration depth as a function of time under different speeds also shows a quadratic relationship.
Fragment Velocity Distribution of Controlled Fragmentation Warhead Under Eccentric Point Initiation
Authors: Mingxue Zhou , Xuelei Feng , Xinming Zhang , heng Wang , teng Deng , Liuqi Ji 
Published: December 2024

Abstract
Three-Point eccentric initiation is one of the most common technologies of directional warhead for enhancing fragment lethality against targets. The fragment velocity distribution is a significant concern in warhead design. However, there is as yet no reasonable theory for predicting the fragment velocity distribution of a specific enhanced shell under three-point eccentric initiation; existing approaches are either limited to single or double-point eccentric initiation scenarios or ignore the effects of detonation gas leakage on fragment acceleration. In this paper, through theoretical analysis and numerical simulations, a new model was established to study the fragment velocity distribution of warhead shells under the combined effects of gas leakage and three-point eccentric initiation. Firstly, an equation for detonation velocity gain of explosives under three-point eccentric initiation was developed by numerical simulations, where the shells were set to be free from disintegration and gas leakage. Secondly, the fracture strain or radius of controlled fragmentation warhead was solved by the disintegration model established in our previous work. Then the equations for detonation velocity gain and the fracture strain were associated with a proposed gas-leakage equation in which the gas expansion was assumed to be locally isentropic. Finally, theoretical analysis was conducted by solving the associated equations. Grooved cylindrical shell was explosively expanded to disintegrate to verify the proposed model. Theoretical predictions of the fragment velocity distribution showed good agreement with experimental results, indicating that the model was suitable for predicting the fragment velocity distribution of an explosively-driven metal grooved cylinders under three-point eccentric initiation. Besides, this study provides an insight into the differences of fragment velocity enhancement among single point initiation, double point initiation and three point initiation.
Study on Failure Determination of Buried Water Supply and Drainage Pipelines Near Explosions
Authors: Chun Li , Bukui Zhou , Dan Luo , Meng Mu 
Published: December 2024

Abstract
An experimental study was conducted on the blast resistance performance of DN200 water supply and drainage pipelines buried 1.5 m deep in sandy soil to investigate the damage effects and damage assessment of underground pipelines in the vicinity of an explosion under weapon impact. Numerical calculations were performed using the finite element software AUTODYN based on the experimental data. The results showed that at a scaled blast distance of 0.394 m/kg1/3, the pipeline could still function normally for water transport, with the steel pipe’s blast-facing surface experiencing radial indentation and overall bending deformation, but the deformation was minimal and insufficient to damage the pipeline’s function. At a scaled blast distance of 0.316 m/kg^1/3, the deformation of the pipeline increased by 34.4% compared to the former case, resulting in leakage, and the blast-facing surface and flange connections were more prone to damage. When determining pipeline damage and failure, the Ovalization Failure Criterion was introduced, and safety thresholds were given in combination with the criterion. Finally, an overpressure-impulse damage criterion and its determination formula for buried water supply and drainage pipelines were established.
Research and test of pre-controlled fragment warhead shell based on 3D printing technology
Authors: Chen Junhan , Zheng Yu , Tao Chuanyun , Liang Zhenchao 
Published: December 2024

Abstract
To overcome the limitations on the total number of rods in discrete rod warhead and to increase its killing range, this paper proposes a center-grooved pre-controlled warhead shell structure based on 3D printing technology. The effects of different grooved grid parameters on shell fracture and fragment formation were compared through water medium recovery test. The fragment recovery results demonstrate that the centrally grooved structure can effectively guide the shell to fracture along the grooved grid pattern, resulting in elongated fragments of the desired size. Numerical models were established by ANSYS/Autody to investigate the process of shell fracture and fragment formation of the centrally grooved pre-controlled warhead shell. The simulation results were analysed in order to ascertain the shell-breaking mechanism and the factors influencing the effective fragment formation rate under the two grooving mesh parameters. This paper provides a reference for the application and design of 3D printing technology in pre-controlled warhead shell.
Design and damage efficiency analysis of multifunctional warhead
Authors: Zhao Yao , Zhai Xin-yi , Liu Han , Guo Zhi-wei , Huang Guang-yan 
Published: December 2024

Abstract
As a component of modern weaponry, the structural design and damage effects of multifunctional warheads are directly linked to their combat performance. Targeting various urban combat objectives, we have proposed and designed a multifunctional warhead structure that integrates multiple destructive elements, including directional and divergent fragments, jets, and linear EFPs, along with corresponding attack modes. Through numerical simulation analysis, we evaluated the damage effects of the different damage elements within this warhead on equivalent target plates, and subsequently conducted static explosion tests to validate the warhead design. The results indicate that the proposed multifunctional warhead features reasonable structural design, and the incorporated destructive elements can reliably damage different targets. This design can be further applied to unmanned combat platforms to effectively engage lightweight armor, urban window railings, ground radars, micro-drones, and other targets, providing references for related warhead structure design and engineering applications.
A comprehensive review and a real blast test on an Earth-Covered Magazine (ECM)
Authors: Tanapornraweekit Ganchai , Dhanasekara Chamil , Tangtermsirikul Somnuk 
Published: December 2024

Abstract
This paper provides a comprehensive review of design recommendations for Earth-Covered Magazines (ECMs) based on various design standards The real blast test from a 40 kg TNT@8.50 m was also conducted to evaluate the blast pressure, blast impulse from the explosion, behavior, and performance of the 1/3 scaled ECM under side explosion. The tested ECM structure showed no damage in all structural components, i.e., front wall, side wall, rear wall, and roof slab. Acceptable damages, such as damage to the soil cover on the side of the ECM and the fall of the front steel door in front of the tested ECM, were observed after the test. Therefore, the tested ECM structure performed well, under the side explosion of 40 kg TNT @ 8.5 m without causing structural damage. From the calculation of blast reflected pressure and re lected impulse, the tested ECM satisfies the pressure and impulse criteria of a standard 7-Bar ECM with a maximum of 20 tons of equivalent TNT stored in a full-scale ECM structure.
Study on the self-sealing properties of POZD coated aluminium composite structure penetrated by projectiles
Authors: Shi Jian-jun , Huang Zheng-xiang , Ma Bin , Jia Xin , Huang Zi-rui 
Published: December 2024

Abstract
The protective technology of fuel tanks has attracted the attention of scholars at home and abroad, and higher requirements have been placed on the protective coatings of fuel tanks. They must not only meet the requirements of impact resistance but also achieve the function of self-healing of perforation. In order to explore the self-healing effect of fuel tank coatings on perforation by projectiles, a POZD-coated aluminium composite structure was designed. The self-healing mechanism of the POZD-coated aluminium composite structure was analysed using a test research method to explore the effects of coating thickness and aluminium thickness on self-healing performance. The results show that the POZD-coated aluminium composite structure exhibits strong self-healing properties when penetrated by projectiles. The self-healing characteristics are significantly influenced by the application technique and thickness of the POZD coating, whereas the thickness of the aluminum plate exerts a relatively minor effect. Through structural design, the POZD-coated aluminium composite structure can achieve complete self-sealing of perforations by 7.62 mm projectiles, providing a technical reference for the design of lightweight self-healing fuel tanks in the future.
Numerical and theoretical studies on axial impact between rods with various noses and a rigid wall
Authors: Wang Yifan , Ye Xuan , Wang Tao , Huang Guangyan 
Published: December 2024

Abstract
Rod drops at times and collides with a substrate, which induces vibration within the rod. The vertical impact between slender rods with different noses and a rigid flat is theoretically and numerically investigated. Equivalent linear contact model for different rod noses are established, based on which a semi-analytical model describing the longitudinal vibration of the rods are derived using 1D wave equation. The predicted displacements agree well with the numerical results. Plastic deformation is mainly concentrated in the rod nose, and the cylindrical part of the rod basically remains elastic. The displacement difference between the top and bottom point represents the compression extent of the cylindrical part, whose variation tendency is consistent with strain energy of the rod. Vibration responses and energy shares of the rods are compared, and sharper truncated-cone nose exhibits better buffering effect. Hemisphere nose is preferred when the plastic dissipation and compression extent are similar due to lower impulse.
Pressure measurement of circumferentially confined gelatin under shock wave
Authors: Xiong M M , Zang L W , Xu C , Ma X J 
Published: December 2024

Abstract
To investigate the pressure response characteristics of head physical surrogate under different sensor arrangement methods, the experimental study on the pressure measurement inside circumferent confined gelatin under the shock waves was conducted. A setup of one-dimensional pressure wave flatbed was constructed, consisting a pneumatic launcher, PVC pipe, and water. The pressure wave of three sensor arrangement methods were compared. The result shows that the three sensor arrangement methods have minimal influence on pressure testing results inside circumferentially constrained gelatin. When the sensitive surface flush with the inner wall (A1) is chosen as a baseline, the peak pressure and impulse differ by less than 3.44% and 5.14% in sensor arrangement method with sensitive surface flush with the pipe center (A2), and by less than 6.75% and 5.83% in sensor arrangement method with sensitive surface into a conical platform flush with the center of the pipe (A3). Smooth and reliable one-dimensional pressure waves can be obtained by the pressure testing method. The one-dimensional pressure wave obtained using this method can effectively be used to study the damage mechanisms of shock waves on the brain and air-containing organs.
Simulation Study on the Thermal Safety of Ammunition in a Multifunctional Launch Vehicle Fire
Authors: Wen Yuchen , Nie Jianxin , Liu Rui , Liang Jiahao , Zhang Tao 
Published: December 2024

Abstract
The multifunctional launch vehicle caught fire due to an unexpected fuel tank fire, creating a fierce flame-burning environment for the onboard ammunition, and posing a huge threat to operators and launch platforms. In order to obtain the thermal safety performance of vehicle-mounted ammunition in case of vehicle fire, the Russian SS-23 missile was taken as the research object. First, the fire dynamics software FDS was used to calculate and analyze the flame structure characteristics and the change law of ammunition ambient temperature field at different stages of fire development. Then the fluid dynamics software CFD was used to calculate and analyze the temperature field distribution characteristics and thermal stimulation response law of ammunition charge. The research results indicate that the uneven distribution of the flame temperature field formed when the fuel tank accidentally catches fire can cause a complex heating environment for on-board ammunition; The internal charge of ammunition continues to heat up under the combined effect of external heating and self-generated heat, and the high-temperature zone shifts towards the interior of the charge, further accelerating the decomposition and heat accumulation of the explosive, ultimately leading to the reaction of the warhead charge. At the same time, different residual fuel levels in the main fuel tank and different wind directions will have an impact on the firing process of the launch vehicle, and the reaction time and position of the onboard ammunition will also vary.
Numerical simulation of combined action of explosion shock wave and prefabricated fragments
Authors: Yan Liu , Jianfen Guo , Jianqin Zhang , Zhuo Lu , Anbang Sun , Zhendong Gao 
Published: December 2024

Abstract
This article is based on the finite element software ANSYS/LS-DYNA to numerically simulate the damage and failure process of prefabricated fragments coupled with explosive shock waves. Obtain the initial velocity law of prefabricated fragments of different shapes and sizes driven by explosive shock waves. Numerical simulations were conducted on three modes of action (fragment action, shock wave action, and coupling action between fragments and shock waves), and it was found that the maximum destructive power was achieved under the coupling action of fragments and shock waves. Under the coupling effect of fragments and shock waves, the maximum deformation of the target plate gradually decreases as the blast distance increases; The law that as the thickness of the target plate increases, the maximum deformation of the target plate gradually decreases.
Research and Optimization of Anti-Ballistic Properties of Gradient Honeycomb Sandwich Panels
Authors: Kuiyuan Sun , Shuhu Li , Jingli Xu 
Published: December 2024

Abstract
In addressing the penetration resistance of honeycomb sandwich panels, a finite element model is established to simulate the penetration problem. The relationship between initial and residual velocity of the fragments is studied. The effects of angle gradient, height gradient, and thickness gradient structures on the ballistic performance of honeycomb sandwich panels are analyzed. Multi-objective optimization design of honeycomb sandwich panels is conducted, resulting in a thickness gradient honeycomb sandwich panel. The results show that the relationship curve between initial and residual velocities of fragments closely matches the theoretical formula. Different gradient structures exhibit varied protective effects on the honeycomb sandwich panels. Compared to the pre-optimized panels, the optimized thickness gradient honeycomb sandwich panels show a significant improvement in protection, with the residual velocity of fragments reduced by 31.82% and the total mass of the sandwich panel reduced by 16.23%.
Experimental study on collision of a rigid wedge-shaped striking bow with ship section model
Authors: Zhao Y J , Guo T T , Li Y C , Zhang L P 
Published: December 2024

Abstract
In fluid-structure coupling collision tests of ship models, it is possible to obtain information about structural damage and accurately simulate the energy distribution during the collision process. Consequently, such tests are most effective in reflecting the true physical process of ship collisions. In this paper, a fluid-structure coupling collision test of a ship model was designed, where the bow of the striking ship was represented by a rigid wedge-shaped striking bow, and a scaled local section model of the struck ship was selected. The striking bow was applied to the side of the section model through a pendulum impact method. Under two different test conditions of head-on and oblique collisions, the collision forces, damage extent, and motion of the ship section model were measured and analyzed. The experimental method proposed in this paper is simple and feasible, and can be used as a means of assessing ship resistance to collision. The data obtained from this test can also provide reference for scholars engaged in related research.
Simulation study on damage effect of multi-cabin implosion on ship
Authors: Yuan Xiaoxia , Wei Chunqiang , Wang Yanye , Ma Hongliang 
Published: December 2024

Abstract
In this paper, the LS-DYNA finite element software was used to simulate the damage process of multi-cabin structure under the explosion in the cabin of the semi-armor-piercing warhead. The newly model of composite shock wave load and fragment load was proposed to study the damage effect of the multi-cabin structure. Combined with the propagation characteristics of the composite loads, the damage mode of the deck and bulkhead of the ship under the action of cabin implosion. Finally, the influence of the charge ratio of the semi-armor-piercing warhead on the damage effect of the multi-cabin structure was analyzed, and in this paper, a charge ratio of 0.35 is more conducive to achieving the entire process from penetration to implosion of multi-cabin.