Pub Date : 2024-10-03DOI: 10.1016/j.ijimpeng.2024.105133
Rami Masri , Shannon Ryan
The perforation of armour plates by quasi-rigid projectiles in ductile hole growth has been demonstrated to be influenced by the ratio of plate thickness to projectile diameter, referred to as the hole slenderness ratio, . Here we propose a new non-dimensional geometric ratio, termed as the target containment ratio, that uses the projectile nose-length in place of the diameter, i.e., . We demonstrate that the hole slenderness ratio is a special approximation of the target containment ratio for projectiles with a nose-shape ratio (projectile nose-length normalised by projectile shank radius) on the order of 3. We validate the proposed relationship via a comprehensive numerical study and through comparison with experimental data for the 14.5 mm BS41 armour piercing bullet, for which the nose-shape ratio is about 2. We show that the new target containment ratio dependent formulation of the specific cavitation energy improves the accuracy of the model suggested in Masri and Ryan (2024). This new formulation is also used to update existing formulae for ballistic limit predictions of monolithic and multilayer ductile targets.
{"title":"Projectile nose-length effect on specific cavitation energy and ballistic limit velocity and thickness","authors":"Rami Masri , Shannon Ryan","doi":"10.1016/j.ijimpeng.2024.105133","DOIUrl":"10.1016/j.ijimpeng.2024.105133","url":null,"abstract":"<div><div>The perforation of armour plates by quasi-rigid projectiles in ductile hole growth has been demonstrated to be influenced by the ratio of plate thickness to projectile diameter, referred to as the hole slenderness ratio, <span><math><mrow><mi>h</mi><mo>/</mo><mi>D</mi></mrow></math></span>. Here we propose a new non-dimensional geometric ratio, termed as the target containment ratio, that uses the projectile nose-length in place of the diameter, i.e., <span><math><mrow><mi>h</mi><mo>/</mo><mi>L</mi></mrow></math></span>. We demonstrate that the hole slenderness ratio is a special approximation of the target containment ratio for projectiles with a nose-shape ratio (projectile nose-length normalised by projectile shank radius) on the order of 3. We validate the proposed relationship via a comprehensive numerical study and through comparison with experimental data for the 14.5 mm BS41 armour piercing bullet, for which the nose-shape ratio is about 2. We show that the new target containment ratio dependent formulation of the specific cavitation energy improves the accuracy of the model suggested in Masri and Ryan (2024). This new formulation is also used to update existing formulae for ballistic limit predictions of monolithic and multilayer ductile targets.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105133"},"PeriodicalIF":5.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.ijimpeng.2024.105137
Gang Wu , Xin Wang , Yuting Wang , Chong Ji , Changxiao Zhao , Yuxuan Gao , Wei Xia
We proposed a bioinspired ceramic/polyurea composite plate that draws on a “brick-mortar” arrangement of nacre layer, with a periodic three-dimensional structure and interlayers polyurea elastomers. We fired a 12.7 mm armor-piercing incendiary bullet using a ballistic gun to conduct depth-of-penetration (DOP) experiments. We analyzed the damage, fracture morphology, and residual DOP of ceramic/polyurea-staggered composite structures (CPSCS), with a theoretical prediction model for the residual DOP. Using the adaptive FEM-SPH algorithm, we compared the damage morphology of CPSCSs. We analyzed projectile penetration process and summarized four toughening modes using stress wave propagation. Based on simulation fitting and theoretical calculations, we obtained the residual DOP curves at different projectile velocities and analyzed the toughening effect of the CPSCSs through the energy dissipation of each structural component. When the areal density was the same, the residual DOP of the CPSCSs decreased by 33.9 %, and the critical velocity theoretically increased by 32.72 %. The error between the model calculations and experimental results was 11 %. The CPSCSs enabled the ceramic to increase the energy absorption efficiency by 179.70 %. With the same structural form, changing the thickness of only one component did not have the same effect on the structural energy-absorption efficiency as changing the entire form.
{"title":"Ballistic properties of bioinspired nacre-like ceramic/polyurea staggered composite structures","authors":"Gang Wu , Xin Wang , Yuting Wang , Chong Ji , Changxiao Zhao , Yuxuan Gao , Wei Xia","doi":"10.1016/j.ijimpeng.2024.105137","DOIUrl":"10.1016/j.ijimpeng.2024.105137","url":null,"abstract":"<div><div>We proposed a bioinspired ceramic/polyurea composite plate that draws on a “brick-mortar” arrangement of nacre layer, with a periodic three-dimensional structure and interlayers polyurea elastomers. We fired a 12.7 mm armor-piercing incendiary bullet using a ballistic gun to conduct depth-of-penetration (DOP) experiments. We analyzed the damage, fracture morphology, and residual DOP of ceramic/polyurea-staggered composite structures (CPSCS), with a theoretical prediction model for the residual DOP. Using the adaptive FEM-SPH algorithm, we compared the damage morphology of CPSCSs. We analyzed projectile penetration process and summarized four toughening modes using stress wave propagation. Based on simulation fitting and theoretical calculations, we obtained the residual DOP curves at different projectile velocities and analyzed the toughening effect of the CPSCSs through the energy dissipation of each structural component. When the areal density was the same, the residual DOP of the CPSCSs decreased by 33.9 %, and the critical velocity theoretically increased by 32.72 %. The error between the model calculations and experimental results was 11 %. The CPSCSs enabled the ceramic to increase the energy absorption efficiency by 179.70 %. With the same structural form, changing the thickness of only one component did not have the same effect on the structural energy-absorption efficiency as changing the entire form.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105137"},"PeriodicalIF":5.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.ijimpeng.2024.105132
Baiyu Chen, Q.M. Li
The strain-rate effect in HJC model is evaluated in this paper. Based on a comparison of strain-rate effects between the HJC and KC models, it shows that the determination and implementation procedures in the HJC model lead to smaller strain-rate effect. Some problems on the determination of strain-rate effect in the HJC model, i.e. the utilisations of the ‘leftward’ pressure correction, over-simplified strength curve and the cross-domain stress data, are discussed, which cause the underestimation of the strain-rate constant C. A more logical and practically-applicable ‘rightward’ pressure correction method is proposed to determine the strain-rate effect in the HJC model. The strain-rate effect determined from the high-pressure data is larger than that determined from the uniaxial compressive data, which facilitate further study on the pressure-dependent strain-rate effect.
{"title":"About the strain-rate effect in HJC model","authors":"Baiyu Chen, Q.M. Li","doi":"10.1016/j.ijimpeng.2024.105132","DOIUrl":"10.1016/j.ijimpeng.2024.105132","url":null,"abstract":"<div><div>The strain-rate effect in HJC model is evaluated in this paper. Based on a comparison of strain-rate effects between the HJC and KC models, it shows that the determination and implementation procedures in the HJC model lead to smaller strain-rate effect. Some problems on the determination of strain-rate effect in the HJC model, i.e. the utilisations of the ‘leftward’ pressure correction, over-simplified strength curve and the cross-domain stress data, are discussed, which cause the underestimation of the strain-rate constant <em>C</em>. A more logical and practically-applicable ‘rightward’ pressure correction method is proposed to determine the strain-rate effect in the HJC model. The strain-rate effect determined from the high-pressure data is larger than that determined from the uniaxial compressive data, which facilitate further study on the pressure-dependent strain-rate effect.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105132"},"PeriodicalIF":5.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.ijimpeng.2024.105130
Brandon K. Zimmerman, Spencer P. Grenley, Alison M. Saunders, Jonathan Lind, David A. Quint, Eric B. Herbold, Israel Lopez, Mukul Kumar
Owing to their ability to provide tunable mechanical responses, lattice materials are frequently studied to elucidate their response to static and dynamic loads. However, these roles are typically in opposition: static loads must be supported sufficiently far away from the onset of buckling or yielding, whereas dynamic loads are typically ameliorated by crushing of the lattice, which provides excellent energy-absorption due to the large plastic deformation accompanying densification. In contrast, this work considers the octet truss as an exemplar topology, in a structural role where it must simultaneously support static loads while enduring high-amplitude impulsive loads. This study focuses on the ability to withstand impulsive loads without yielding, an essential prerequisite to enduring dual loading. Computational studies using the ALE3D hydrocode were performed to examine the response of the octet truss under a short temporal width impulse shape associated with laser-driven shocks. A key finding was that covering the lattice with a solid face sheet and treating this face sheet thickness as a design variable allows the Taylor-like pulse to be attenuated prior to entering the weaker lattice, at the cost of added mass up front. Experimental validation was accomplished by laser-driven shock testing, using octet trusses printed out of Ti-5Al-5V-5Mo-3Cr. The results show that for a given quantity of mass, the attenuation is maximized when as much mass as possible is moved into the face sheet, leaving a more slender lattice structure. The effect of placing mass in the face sheet rather than lattice beams dominates the effect of relative density, to the point where a low-mass structure with most of the mass concentrated in the face sheet can outperform a high-mass structure with most of the mass in the lattice. By further understanding the propagation of short pulse width waves within under-dense structures, this study expand the domain of applicability of such structures, including lattice materials, to challenging dual-loading regimes spanning decades of strain rates.
{"title":"Solid face sheets enable lattice metamaterials to withstand high-amplitude impulsive loading without yielding","authors":"Brandon K. Zimmerman, Spencer P. Grenley, Alison M. Saunders, Jonathan Lind, David A. Quint, Eric B. Herbold, Israel Lopez, Mukul Kumar","doi":"10.1016/j.ijimpeng.2024.105130","DOIUrl":"10.1016/j.ijimpeng.2024.105130","url":null,"abstract":"<div><div>Owing to their ability to provide tunable mechanical responses, lattice materials are frequently studied to elucidate their response to static and dynamic loads. However, these roles are typically in opposition: static loads must be supported sufficiently far away from the onset of buckling or yielding, whereas dynamic loads are typically ameliorated by crushing of the lattice, which provides excellent energy-absorption due to the large plastic deformation accompanying densification. In contrast, this work considers the octet truss as an exemplar topology, in a structural role where it must simultaneously support static loads while enduring high-amplitude impulsive loads. This study focuses on the ability to withstand impulsive loads without yielding, an essential prerequisite to enduring dual loading. Computational studies using the ALE3D hydrocode were performed to examine the response of the octet truss under a short temporal width impulse shape associated with laser-driven shocks. A key finding was that covering the lattice with a solid face sheet and treating this face sheet thickness as a design variable allows the Taylor-like pulse to be attenuated prior to entering the weaker lattice, at the cost of added mass up front. Experimental validation was accomplished by laser-driven shock testing, using octet trusses printed out of Ti-5Al-5V-5Mo-3Cr. The results show that for a given quantity of mass, the attenuation is maximized when as much mass as possible is moved into the face sheet, leaving a more slender lattice structure. The effect of placing mass in the face sheet rather than lattice beams dominates the effect of relative density, to the point where a low-mass structure with most of the mass concentrated in the face sheet can outperform a high-mass structure with most of the mass in the lattice. By further understanding the propagation of short pulse width waves within under-dense structures, this study expand the domain of applicability of such structures, including lattice materials, to challenging dual-loading regimes spanning decades of strain rates.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105130"},"PeriodicalIF":5.1,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.ijimpeng.2024.105134
Yanxin Ge , Pengwan Chen , Xuan Wu , Qiang Zhou , Hang Fan , Chenguang Wang , Changqing Zhou , Mengce Liu , Lisha Deng , Qiang Zhou , Bin Jia
In this work, explosive welding technique was used to fabricate 2 mm + 2 mm thick double layered Weldox700E steel targets. The bonding interface exhibited wave-shaped patterns without obvious micro-defects, grain refinement and grain elongation were observed. With specially designed shear specimen and tensile specimen, Ultimate stresses of the bonding interface under shear and tensile loadings were measured to be 526 MPa and 683 MPa, respectively. Ballistic impact tests against ogival-nosed projectiles were conducted on both explosively welded double-layered targets and double-layered contact targets. Ballistic limit velocities of the two target configurations were respectively 225.32 m/s and 203.98 m/s , with the former being 10.5 % higher than the latter. For both target configurations, localized bulging and petal-shaped cracking were observed; specially, welded bonding interface remains well bonded even after perforation of the projectile. Combining experimental results and numerical simulations, it was found that the explosively welded double-layered targets exhibited better ballistic performance than double-layered contact ones. The good welded bonding interface provides a better overall deformation capability for the explosively welded double-layered target, which is an important reason for the improved ballistic performance of the target. Although hardness tests show that there is a significant hardened layer in the explosively welded double-layered target, and the hardness value can reach up to 409.4 HV. However, the thin hardened layer cannot significantly improve the ballistic performance of the explosively welded double-layered target in the high-speed impact process of the projectile.
在这项工作中，采用爆炸焊接技术制造了 2 mm + 2 mm 厚的双层 Weldox700E 钢靶。焊接界面呈现波浪形图案，无明显微缺陷，观察到晶粒细化和晶粒伸长。通过专门设计的剪切试样和拉伸试样，测得粘接界面在剪切和拉伸载荷下的极限应力分别为 526 兆帕和 683 兆帕。在爆炸焊接双层靶和双层接触靶上进行了口鼻弹丸的弹道冲击试验。两种目标配置的弹道极限速度分别为 225.32 m/s 和 203.98 m/s，前者比后者高 10.5%。在这两种靶件结构中，都观察到了局部隆起和花瓣状裂纹；特别是，即使在射弹穿孔后，焊接粘接界面仍然保持良好的粘接状态。结合实验结果和数值模拟发现，爆炸焊接双层靶的弹道性能优于双层接触靶。良好的焊接结合界面为爆炸焊接双层靶提供了更好的整体变形能力，这是靶件弹道性能提高的重要原因。虽然硬度测试表明，爆炸焊接双层靶材中存在明显的硬化层，硬度值最高可达 409.4 HV。但是，在弹丸高速撞击过程中，薄硬化层并不能明显改善爆炸焊接双层靶的弹道性能。
{"title":"Experimental and numerical study on ballistic impact behavior of explosively-welded double-layered Weldox700E targets against ogival-nosed projectiles","authors":"Yanxin Ge , Pengwan Chen , Xuan Wu , Qiang Zhou , Hang Fan , Chenguang Wang , Changqing Zhou , Mengce Liu , Lisha Deng , Qiang Zhou , Bin Jia","doi":"10.1016/j.ijimpeng.2024.105134","DOIUrl":"10.1016/j.ijimpeng.2024.105134","url":null,"abstract":"<div><div>In this work, explosive welding technique was used to fabricate 2 mm + 2 mm thick double layered Weldox700E steel targets. The bonding interface exhibited wave-shaped patterns without obvious micro-defects, grain refinement and grain elongation were observed. With specially designed shear specimen and tensile specimen, Ultimate stresses of the bonding interface under shear and tensile loadings were measured to be 526 MPa and 683 MPa, respectively. Ballistic impact tests against ogival-nosed projectiles were conducted on both explosively welded double-layered targets and double-layered contact targets. Ballistic limit velocities of the two target configurations were respectively 225.32 m/s and 203.98 m/s , with the former being 10.5 % higher than the latter. For both target configurations, localized bulging and petal-shaped cracking were observed; specially, welded bonding interface remains well bonded even after perforation of the projectile. Combining experimental results and numerical simulations, it was found that the explosively welded double-layered targets exhibited better ballistic performance than double-layered contact ones. The good welded bonding interface provides a better overall deformation capability for the explosively welded double-layered target, which is an important reason for the improved ballistic performance of the target. Although hardness tests show that there is a significant hardened layer in the explosively welded double-layered target, and the hardness value can reach up to 409.4 HV. However, the thin hardened layer cannot significantly improve the ballistic performance of the explosively welded double-layered target in the high-speed impact process of the projectile.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105134"},"PeriodicalIF":5.1,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.ijimpeng.2024.105131
Liuliang Cui , Xihong Zhang , Hong Hao
This paper presents a novel approach for predicting the dynamic shear forces and the maximum displacement of clamped reinforced concrete (RC) beams subjected to impact loading. By integrating wave propagation effects, membrane actions and the time-dependent acceleration distribution into the analysis, the study presents an improved approach based on single-degree-of-freedom (SDOF) analysis and overcomes the limitations of conventional SDOF method. The proposed model is validated against experimental data and finite-element simulations, demonstrating its reliability and accuracy in predicting dynamic response. Based on the validated model, a series of design charts are generated facilitating quick predictions of the maximum shear force at support and the maximum displacement of RC beams under impact, offering practical tools for engineers to enhance the safety and resilience of RC beams against impact loading.
{"title":"Prediction of dynamic shear and maximum displacement of clamped reinforced concrete beams subjected to impact loading","authors":"Liuliang Cui , Xihong Zhang , Hong Hao","doi":"10.1016/j.ijimpeng.2024.105131","DOIUrl":"10.1016/j.ijimpeng.2024.105131","url":null,"abstract":"<div><div>This paper presents a novel approach for predicting the dynamic shear forces and the maximum displacement of clamped reinforced concrete (RC) beams subjected to impact loading. By integrating wave propagation effects, membrane actions and the time-dependent acceleration distribution into the analysis, the study presents an improved approach based on single-degree-of-freedom (SDOF) analysis and overcomes the limitations of conventional SDOF method. The proposed model is validated against experimental data and finite-element simulations, demonstrating its reliability and accuracy in predicting dynamic response. Based on the validated model, a series of design charts are generated facilitating quick predictions of the maximum shear force at support and the maximum displacement of RC beams under impact, offering practical tools for engineers to enhance the safety and resilience of RC beams against impact loading.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105131"},"PeriodicalIF":5.1,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.ijimpeng.2024.105126
Rannveig Marie Færgestad , Lorenzo Olivieri , Cinzia Giacomuzzo , Stefano Lopresti , Giovanni Pitacco , Alessandro Francesconi , Tiziana Cardone , Kevin Anthony Ford , Jens Kristian Holmen , Odd Sture Hopperstad , Tore Børvik
Aluminium Whipple shields are commonly used to protect spacecraft against hypervelocity impacts (HVIs) from orbital debris and micrometeoroids. Since numerical models nowadays are vital in the design process of protective shields, experimental studies of HVI are important to ensure that the numerical methods are robust and capable of accurately describing a range of impact conditions and material responses. The shatter regime is the transition velocity range between ballistic impact and hypervelocity impact, typically defined from 3 to 7 km/s. In this region, the debris cloud generated by the impact transitions from a few large, solid fragments at the lower end of the velocity range, to a high number of smaller fragments and partial melting of the projectile at the higher velocities. In this study, an experimental campaign of 22 normal impacts of spherical AA1100 projectiles on AA6061-T6 Whipple shields is performed, where the impact velocity and bumper thickness are systematically varied to study the change in debris cloud characteristics and shield damage. Impact velocities from 2.6 to 5.0 km/s are investigated, combined with bumper thicknesses of 1.0, 1.5 and 2.0 mm. Analysis of the experimental results is conducted using high-speed camera footage of the debris clouds and post-impact analysis of bumpers and rear walls. A numerical model is then established using the Smoothed Particle Hydrodynamics (SPH) method in the IMPETUS Solver, and the numerical results are compared to the experimental data. The simulations are able to capture the main trends found in the experimental study, and show a similar level of damage as the experiments when varying the impact velocity and bumper thickness. The simulations have somewhat smaller fragments generated in the debris cloud than in the experiments, leading to slightly less damage inflicted on the rear wall.
{"title":"Hypervelocity impact against aluminium Whipple shields in the shatter regime with systematic parameter variation: An experimental and numerical study","authors":"Rannveig Marie Færgestad , Lorenzo Olivieri , Cinzia Giacomuzzo , Stefano Lopresti , Giovanni Pitacco , Alessandro Francesconi , Tiziana Cardone , Kevin Anthony Ford , Jens Kristian Holmen , Odd Sture Hopperstad , Tore Børvik","doi":"10.1016/j.ijimpeng.2024.105126","DOIUrl":"10.1016/j.ijimpeng.2024.105126","url":null,"abstract":"<div><div>Aluminium Whipple shields are commonly used to protect spacecraft against hypervelocity impacts (HVIs) from orbital debris and micrometeoroids. Since numerical models nowadays are vital in the design process of protective shields, experimental studies of HVI are important to ensure that the numerical methods are robust and capable of accurately describing a range of impact conditions and material responses. The shatter regime is the transition velocity range between ballistic impact and hypervelocity impact, typically defined from 3 to 7 km/s. In this region, the debris cloud generated by the impact transitions from a few large, solid fragments at the lower end of the velocity range, to a high number of smaller fragments and partial melting of the projectile at the higher velocities. In this study, an experimental campaign of 22 normal impacts of spherical AA1100 projectiles on AA6061-T6 Whipple shields is performed, where the impact velocity and bumper thickness are systematically varied to study the change in debris cloud characteristics and shield damage. Impact velocities from 2.6 to 5.0 km/s are investigated, combined with bumper thicknesses of 1.0, 1.5 and 2.0 mm. Analysis of the experimental results is conducted using high-speed camera footage of the debris clouds and post-impact analysis of bumpers and rear walls. A numerical model is then established using the Smoothed Particle Hydrodynamics (SPH) method in the IMPETUS Solver, and the numerical results are compared to the experimental data. The simulations are able to capture the main trends found in the experimental study, and show a similar level of damage as the experiments when varying the impact velocity and bumper thickness. The simulations have somewhat smaller fragments generated in the debris cloud than in the experiments, leading to slightly less damage inflicted on the rear wall.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105126"},"PeriodicalIF":5.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the split Hopkinson pressure bar (SHPB) experiments, significant measurement errors can arise due to severe radial inertia and friction effects. Previous studies have developed various correction methods for these two effects. However, these methods have problems such as over-reliance on the volume invariance assumption of the specimen and inconsistent assumptions on the deformation patterns of the two effects, which limit their universality and effectiveness. Therefore, this paper integrates the radial inertia effect and friction effect in a unified deformation framework through reasonable assumptions, and proposes a method to correct the specimen from a complex stress state to a uniaxial stress state. SHPB numerical simulation experiments demonstrate that this method effectively eliminates the combined effects of radial inertia and friction on measurement results for both elastic and viscoelastic materials, including the size effect associated with these two factors. Additionally, the paper presents a scheme to determine the friction coefficient using the size effect of the specimens when the friction coefficient between the specimen and the bar is unknown. Finally, the method was applied to correct the stresses measured in SHPB experiments on silicone rubber of different diameters. It successfully eliminated discrepancies in the stress-strain relationships between specimens of various sizes and determined a friction coefficient that fell within a reasonable range.
{"title":"Correction method and verification of radial inertia and friction effects under a unified deformation framework in SHPB experiments on soft materials","authors":"Ping Ni, Liqun Tang, Peidong Xu, Xinyuan Wang, Bao Yang, Yiping Liu, Zejia Liu, Zhenyu Jiang, Licheng Zhou","doi":"10.1016/j.ijimpeng.2024.105129","DOIUrl":"10.1016/j.ijimpeng.2024.105129","url":null,"abstract":"<div><div>During the split Hopkinson pressure bar (SHPB) experiments, significant measurement errors can arise due to severe radial inertia and friction effects. Previous studies have developed various correction methods for these two effects. However, these methods have problems such as over-reliance on the volume invariance assumption of the specimen and inconsistent assumptions on the deformation patterns of the two effects, which limit their universality and effectiveness. Therefore, this paper integrates the radial inertia effect and friction effect in a unified deformation framework through reasonable assumptions, and proposes a method to correct the specimen from a complex stress state to a uniaxial stress state. SHPB numerical simulation experiments demonstrate that this method effectively eliminates the combined effects of radial inertia and friction on measurement results for both elastic and viscoelastic materials, including the size effect associated with these two factors. Additionally, the paper presents a scheme to determine the friction coefficient using the size effect of the specimens when the friction coefficient between the specimen and the bar is unknown. Finally, the method was applied to correct the stresses measured in SHPB experiments on silicone rubber of different diameters. It successfully eliminated discrepancies in the stress-strain relationships between specimens of various sizes and determined a friction coefficient that fell within a reasonable range.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105129"},"PeriodicalIF":5.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.ijimpeng.2024.105123
Beibei Li, Bin Feng, Li Chen
Predicting plate penetration by rigid projectiles (PPRP) is crucial in terminal ballistics, with broad applications in civil and military engineering. Empirical and analytical methods face challenges in predicting field variables like displacement and stress in target plates. Although numerical methods offer high accuracy, they suffer from low computational efficiency. Herein, we introduce an efficient data-driven machine learning (ML) method based on graph neural networks (GNNs), named PGN, specifically tailored to address the PPRP problem. Unlike traditional ML methods that establish direct input-output mappings, PGN predicts comprehensive spatial-temporal information pertaining to the projectile-target interaction process. A thorough analysis of PGN's performance in terms of accuracy, computational efficiency and generalization ability was performed. Compared to validated results of numerical simulations, PGN maintained high precision with RMSE for displacement, stress, and strain predictions below 0.5 %, 9.5 %, and 2.1 %, respectively. It also achieved R2 values exceeding 0.92 for the time history of projectile velocity and acceleration, while requiring only 9.8 % of the computation time compared to LS-DYNA. In generalization tests, PGN exhibited remarkable adaptability in tackling challenging scenarios that extend far beyond the training data distribution, with overall RMSE between 11 % and 13 %. Furthermore, we find that the maximum information propagation capacity of a simulated physical system must meet or exceed the information propagation need of the real-world physical phenomenon it aims to replicate. Consequently, an approach was proposed to determine the critical connectivity radius of the massage passing method directly from the wave speed in the target medium, which greatly improved the accuracy and efficiency of PGN.
{"title":"A graph network-based learnable simulator for spatial-temporal prediction of rigid projectile penetration","authors":"Beibei Li, Bin Feng, Li Chen","doi":"10.1016/j.ijimpeng.2024.105123","DOIUrl":"10.1016/j.ijimpeng.2024.105123","url":null,"abstract":"<div><div>Predicting plate penetration by rigid projectiles (PPRP) is crucial in terminal ballistics, with broad applications in civil and military engineering. Empirical and analytical methods face challenges in predicting field variables like displacement and stress in target plates. Although numerical methods offer high accuracy, they suffer from low computational efficiency. Herein, we introduce an efficient data-driven machine learning (ML) method based on graph neural networks (GNNs), named PGN, specifically tailored to address the PPRP problem. Unlike traditional ML methods that establish direct input-output mappings, PGN predicts comprehensive spatial-temporal information pertaining to the projectile-target interaction process. A thorough analysis of PGN's performance in terms of accuracy, computational efficiency and generalization ability was performed. Compared to validated results of numerical simulations, PGN maintained high precision with RMSE for displacement, stress, and strain predictions below 0.5 %, 9.5 %, and 2.1 %, respectively. It also achieved <em>R</em><sup>2</sup> values exceeding 0.92 for the time history of projectile velocity and acceleration, while requiring only 9.8 % of the computation time compared to LS-DYNA. In generalization tests, PGN exhibited remarkable adaptability in tackling challenging scenarios that extend far beyond the training data distribution, with overall RMSE between 11 % and 13 %. Furthermore, we find that the maximum information propagation capacity of a simulated physical system must meet or exceed the information propagation need of the real-world physical phenomenon it aims to replicate. Consequently, an approach was proposed to determine the critical connectivity radius of the massage passing method directly from the wave speed in the target medium, which greatly improved the accuracy and efficiency of PGN.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105123"},"PeriodicalIF":5.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1016/j.ijimpeng.2024.105125
Zihan Zhu , Xiaoshao Kong , Hu Zhou , Cheng Zheng , Weiguo Wu
Composite armor plays a crucial role as the primary defense against high-velocity impacts from fragments and projectiles. However, balancing the need for lightweight structures with the requirement for robust protection remains a significant engineering challenge. Traditional approaches for predicting the protective performance of armor typically involve a combination of experimental testing and numerical simulations, both of which can be resource-intensive and costly. In contrast, data-driven methods combined with machine learning have demonstrated the potential to significantly reduce both time and economic costs, highlighting their substantial advantages in various engineering domains. Unfortunately, a mature machine learning framework for predicting the performance of multilayer composite armor against high-velocity impacts from large fragments has yet to be established. In this paper, a novel data-driven framework for predicting the ballistic performance of composite armor using a hybrid model of Support Vector Machine and Deep Neural Network was established. This framework employed hyperparameter optimization to enhance predictive performance, yielding a model with excellent accuracy. The proposed model was adaptable to multilayered armor with varying layer thicknesses, enabling rapid predictions of armor penetration, residual projectile kinetic energy, and armor deformation.
{"title":"A hybrid data-driven machine learning framework for predicting the impact resistance of composite armor","authors":"Zihan Zhu , Xiaoshao Kong , Hu Zhou , Cheng Zheng , Weiguo Wu","doi":"10.1016/j.ijimpeng.2024.105125","DOIUrl":"10.1016/j.ijimpeng.2024.105125","url":null,"abstract":"<div><div>Composite armor plays a crucial role as the primary defense against high-velocity impacts from fragments and projectiles. However, balancing the need for lightweight structures with the requirement for robust protection remains a significant engineering challenge. Traditional approaches for predicting the protective performance of armor typically involve a combination of experimental testing and numerical simulations, both of which can be resource-intensive and costly. In contrast, data-driven methods combined with machine learning have demonstrated the potential to significantly reduce both time and economic costs, highlighting their substantial advantages in various engineering domains. Unfortunately, a mature machine learning framework for predicting the performance of multilayer composite armor against high-velocity impacts from large fragments has yet to be established. In this paper, a novel data-driven framework for predicting the ballistic performance of composite armor using a hybrid model of Support Vector Machine and Deep Neural Network was established. This framework employed hyperparameter optimization to enhance predictive performance, yielding a model with excellent accuracy. The proposed model was adaptable to multilayered armor with varying layer thicknesses, enabling rapid predictions of armor penetration, residual projectile kinetic energy, and armor deformation.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"195 ","pages":"Article 105125"},"PeriodicalIF":5.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0734743X24002501/pdfft?md5=edad608188e164a3bc4026d92471f9d4&pid=1-s2.0-S0734743X24002501-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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