Pub Date : 2025-11-11DOI: 10.1016/j.ijimpeng.2025.105589
Mario Scholze , Luisa Schottstedt , Maximilian Hinze , Philipp Frint , Martin F.-X. Wagner
Formation of adiabatic shear bands (ASB) as a deformation mechanism occurs particularly at high (shear) strain rates in metallic materials. A detailed analysis of ASB nucleation and growth, and of the contributions of the underlying mechanisms such as thermal or microstructural softening, is experimentally challenging. In this study, we present newly designed S-shaped sample geometries that allow an in-situ characterization of shear banding under different stress states. Local shear deformation occurs in a geometrically well-defined shear zone during uniaxial compression of the S-shaped samples. Considering both numerical simulations and experimental measurements, we demonstrate that the predominant shear stress can be superimposed with either tensile or compressive stresses by slightly varying the geometry of the shear zone. Moreover, we show that the sample geometry is ideally suited for the application of digital image correlation for strain (rate) mapping as well as temperature measurements at high loading velocities. Metallographic preparation of the samples prior to testing enables in-situ microstructural observations during dynamic deformation. The sample geometry is validated by dynamic experiments using a Ti-10V-2Fe-3Al alloy in a Split-Hopkinson Pressure Bar (SHPB) under nominal strain rates of >103 s-1 (which corresponds to local shear rates up to 105 s-1). Our experimental and numerical results demonstrate that the novel sample geometry facilitates detailed investigations focused on the formation and growth of adiabatic shear bands.
{"title":"Tailored planar S-shaped samples for in-situ characterization of adiabatic shear banding under controlled stress triaxialities","authors":"Mario Scholze , Luisa Schottstedt , Maximilian Hinze , Philipp Frint , Martin F.-X. Wagner","doi":"10.1016/j.ijimpeng.2025.105589","DOIUrl":"10.1016/j.ijimpeng.2025.105589","url":null,"abstract":"<div><div>Formation of adiabatic shear bands (ASB) as a deformation mechanism occurs particularly at high (shear) strain rates in metallic materials. A detailed analysis of ASB nucleation and growth, and of the contributions of the underlying mechanisms such as thermal or microstructural softening, is experimentally challenging. In this study, we present newly designed S-shaped sample geometries that allow an in-situ characterization of shear banding under different stress states. Local shear deformation occurs in a geometrically well-defined shear zone during uniaxial compression of the S-shaped samples. Considering both numerical simulations and experimental measurements, we demonstrate that the predominant shear stress can be superimposed with either tensile or compressive stresses by slightly varying the geometry of the shear zone. Moreover, we show that the sample geometry is ideally suited for the application of digital image correlation for strain (rate) mapping as well as temperature measurements at high loading velocities. Metallographic preparation of the samples prior to testing enables in-situ microstructural observations during dynamic deformation. The sample geometry is validated by dynamic experiments using a Ti-10V-2Fe-3Al alloy in a Split-Hopkinson Pressure Bar (SHPB) under nominal strain rates of >10<sup>3</sup> s<sup>-1</sup> (which corresponds to local shear rates up to 10<sup>5</sup> s<sup>-1</sup>). Our experimental and numerical results demonstrate that the novel sample geometry facilitates detailed investigations focused on the formation and growth of adiabatic shear bands.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"212 ","pages":"Article 105589"},"PeriodicalIF":5.1,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078457","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 : 2025-11-10DOI: 10.1016/j.ijimpeng.2025.105586
Xiongwen Jiang , Yu Tang , Wei Zhang , Jun Wang , Yanjie Zhao , Lunping Zhang , Wenwei Wu
The safety of ship structures under underwater explosions depends on their stiffness and strength. The coupled loads of underwater shock waves and fragments can cause severe deformation and damage to the structures. To accurately assess this situation, a novel underwater shock wave and fragment coupled load testing system (SF-CLTS) has been developed by modifying the gas gun system. By controlling the time difference of the launching system as well as the velocities of the flyer and bullet, the time interval of the coupled loads can be adjusted. The deformation process of the target plate can be visualized using the 3D digital image correlation (3D-DIC) method combined with images captured by high-speed cameras. The dynamic deformation and damage of aluminum alloy plates under the aforementioned loads were studied by means of SF-CLTS. Meanwhile, the theoretical analysis of the impact process between the thin plate and the fluid was carried out using the energy method and the plastic hinge-spring model, with supplementary and comparative analysis using experimental data. This revealed the correlation between structural deformation and the intensity of external shock waves (peak pressure and exponential decay time). This method is crucial for the safety assessment and design of ship structures, and helps to deepen our understanding of the complex impact effects of underwater explosions.
{"title":"Investigation on the underwater explosion coupled loads testing technique and deformation response of thin plate subjected to underwater shock and fragments","authors":"Xiongwen Jiang , Yu Tang , Wei Zhang , Jun Wang , Yanjie Zhao , Lunping Zhang , Wenwei Wu","doi":"10.1016/j.ijimpeng.2025.105586","DOIUrl":"10.1016/j.ijimpeng.2025.105586","url":null,"abstract":"<div><div>The safety of ship structures under underwater explosions depends on their stiffness and strength. The coupled loads of underwater shock waves and fragments can cause severe deformation and damage to the structures. To accurately assess this situation, a novel underwater shock wave and fragment coupled load testing system (SF-CLTS) has been developed by modifying the gas gun system. By controlling the time difference of the launching system as well as the velocities of the flyer and bullet, the time interval of the coupled loads can be adjusted. The deformation process of the target plate can be visualized using the 3D digital image correlation (3D-DIC) method combined with images captured by high-speed cameras. The dynamic deformation and damage of aluminum alloy plates under the aforementioned loads were studied by means of SF-CLTS. Meanwhile, the theoretical analysis of the impact process between the thin plate and the fluid was carried out using the energy method and the plastic hinge-spring model, with supplementary and comparative analysis using experimental data. This revealed the correlation between structural deformation and the intensity of external shock waves (peak pressure and exponential decay time). This method is crucial for the safety assessment and design of ship structures, and helps to deepen our understanding of the complex impact effects of underwater explosions.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105586"},"PeriodicalIF":5.1,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579279","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 : 2025-11-10DOI: 10.1016/j.ijimpeng.2025.105587
Zhi-yong Yin , Qi-guang He , Xiao-wei Chen
Fragmentation analysis in explosively driven cylindrical shells is crucial for weapon development and structural protection. To evaluate the overall response of protective structures to explosive fragments, it is essential to clarify the spatial distribution characteristics of the fragments. This study investigates the influence of fracture mode on fragment morphology and spatial distribution through numerical simulations, highlighting the non-uniform fragment distribution. A damage analysis method based on the kinetic energy of fragments is proposed, which illustrates both the spatial distribution and energy concentration in specific areas. The results reveal that the kinetic energy distribution of fragments exhibits a clustering effect only in shear fracture, corresponding to the elongated fragments generated from the middle of the cylindrical shell. Furthermore, a theoretical model is developed to determine the maximum kinetic energy angle, facilitating the rapid identification of severely damaged regions in protective structures. The experimental results validate the non-uniform distribution of perforation areas on witness plates and demonstrate that the theoretical model can accurately predict the location and extent of severe damage under varying conditions. This study provides an energy-based theoretical framework for damage assessment of explosive fragments, offering valuable insights for damage and protection design in fields such as the ship damage evaluation and the blast resistance of concrete structures.
{"title":"Spatial distribution and damage prediction of explosive fragments in cylindrical shells","authors":"Zhi-yong Yin , Qi-guang He , Xiao-wei Chen","doi":"10.1016/j.ijimpeng.2025.105587","DOIUrl":"10.1016/j.ijimpeng.2025.105587","url":null,"abstract":"<div><div>Fragmentation analysis in explosively driven cylindrical shells is crucial for weapon development and structural protection. To evaluate the overall response of protective structures to explosive fragments, it is essential to clarify the spatial distribution characteristics of the fragments. This study investigates the influence of fracture mode on fragment morphology and spatial distribution through numerical simulations, highlighting the non-uniform fragment distribution. A damage analysis method based on the kinetic energy of fragments is proposed, which illustrates both the spatial distribution and energy concentration in specific areas. The results reveal that the kinetic energy distribution of fragments exhibits a clustering effect only in shear fracture, corresponding to the elongated fragments generated from the middle of the cylindrical shell. Furthermore, a theoretical model is developed to determine the maximum kinetic energy angle, facilitating the rapid identification of severely damaged regions in protective structures. The experimental results validate the non-uniform distribution of perforation areas on witness plates and demonstrate that the theoretical model can accurately predict the location and extent of severe damage under varying conditions. This study provides an energy-based theoretical framework for damage assessment of explosive fragments, offering valuable insights for damage and protection design in fields such as the ship damage evaluation and the blast resistance of concrete structures.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105587"},"PeriodicalIF":5.1,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579278","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 : 2025-11-10DOI: 10.1016/j.ijimpeng.2025.105585
Minghao Zhang , Zengqiang Cao , Shuaijia Kou , Yingjiang Guo , Yuanzhuo He , Yuejie Cao , Lubin Huo
The CFRP joining structures of aircraft fuselage not only withstand circumferential tensile loads, but also face the risk of external impacts. This study employed an impact approach based on electromagnetic force loading to conduct electromagnetic impact (EMI) tests at varying energy levels on CFRP/Al (aluminum alloy) four-rivet double-sided countersunk riveted joints in aircraft fuselage structures. The impact response and damage behavior were investigated. Subsequently, residual tensile strength and fatigue life tests were performed on these pre-impact riveted joints. During quasi-static tensile tests, acoustic emission (AE) technology was used to monitor the damage process of the structures, and six categories of damage were identified using the evidential c-means (ECM) algorithm. The research results indicate that an increase in the impact strain rate slightly raises the damage threshold load of CFRP laminates. The presence of rivets prevents further propagation of delamination, and the deformation of Al sheet can serve as an effective auxiliary means for detecting impact damage. For multi-riveted joints, the effects of impact behavior on the structure are localized, improving energy absorption without reducing the residual tensile strength. However, the CFRP damage and Al sheet deformation caused by the impact significantly reduce the fatigue life of the joints.
{"title":"Effect of pre-impact behavior based on electromagnetic force loading on the residual tensile strength and fatigue life of CFRP/Al multi-riveted structure","authors":"Minghao Zhang , Zengqiang Cao , Shuaijia Kou , Yingjiang Guo , Yuanzhuo He , Yuejie Cao , Lubin Huo","doi":"10.1016/j.ijimpeng.2025.105585","DOIUrl":"10.1016/j.ijimpeng.2025.105585","url":null,"abstract":"<div><div>The CFRP joining structures of aircraft fuselage not only withstand circumferential tensile loads, but also face the risk of external impacts. This study employed an impact approach based on electromagnetic force loading to conduct electromagnetic impact (EMI) tests at varying energy levels on CFRP/Al (aluminum alloy) four-rivet double-sided countersunk riveted joints in aircraft fuselage structures. The impact response and damage behavior were investigated. Subsequently, residual tensile strength and fatigue life tests were performed on these pre-impact riveted joints. During quasi-static tensile tests, acoustic emission (AE) technology was used to monitor the damage process of the structures, and six categories of damage were identified using the evidential c-means (ECM) algorithm. The research results indicate that an increase in the impact strain rate slightly raises the damage threshold load of CFRP laminates. The presence of rivets prevents further propagation of delamination, and the deformation of Al sheet can serve as an effective auxiliary means for detecting impact damage. For multi-riveted joints, the effects of impact behavior on the structure are localized, improving energy absorption without reducing the residual tensile strength. However, the CFRP damage and Al sheet deformation caused by the impact significantly reduce the fatigue life of the joints.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105585"},"PeriodicalIF":5.1,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528630","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 : 2025-11-09DOI: 10.1016/j.ijimpeng.2025.105581
Júlio Jorge Braga de Carvalho Nunes , Pablo Augusto Krahl , Flávio de Andrade Silva
The demand for resilient materials in impact-prone structures has increased interest in UHPC reinforced with steel fibers. Known for its strength and energy absorption capacity, UHPC is a promising construction material that can be used under dynamic loading. However, a lack of tensile data at high strain rates (>100 s⁻¹) limits the development of predictive models and safe structural design. This study addresses this gap by investigating the strain-rate-sensitive tensile behavior of UHPC reinforced with smooth (SF) and hooked-end fibers (HF), using direct tension tests across a wide strain-rate range (quasi-static to ∼200 s⁻¹). Results demonstrate that, while matrix strength controls the first peak stress, fiber geometry governs post-cracking behavior, energy dissipation, and ductility. UHPC SF achieved up to 35 % higher second peak loads and 18–22 % greater dynamic toughness than UHPC HF, reaching 674 kJ/m³ at 195 s⁻¹. In contrast, UHPC HF reached higher maximum peak loads (up to 32 kN) and more stable first-peak responses, but suffered abrupt post-peak stress drops, with toughness values limited to ∼572 kJ/m³. At higher strain levels, UHPC SF benefited from its uniform fiber distribution and frictional pull-out, while UHPC HF relied on mechanical anchorage that was less effective beyond ∼100 s⁻¹. The Dynamic Increase Factor (DIF) for peak load ranged from 2.7 to 4.2 for UHPC HF and from 3.3 to 3.9 for UHPC SF, significantly exceeding by up to 40 % the typical DIF range (1.5–3.0) reported for conventional concretes. Ultimate strain reached up to 4.5 % at 195 s⁻¹, with UHPC SF exhibiting a more stable strain evolution, while UHPC HF showed sudden cracking and steeper load drops. This behavior highlights the crucial role of fiber bridging in absorbing high-velocity impacts. This comprehensive experimental campaign also supported the calibration of a numerical simulation by the Concrete Damage Plasticity (CDP) model with strain rate dependence, which reproduced the key post-peak features of both UHPCs and predicted peak loads with less than 8 % deviation across the entire strain-rate range, including interpolated intervals lacking direct experimental data. Numerical predictions aligned with experimental DIF trends, confirming the robustness of the model for dynamic tensile loading. In addition, the predictive model for DIF captured experimental behavior across all strain-rate ranges, confirming its applicability for UHPC under extreme dynamic loading. This integrative approach, combining mechanical characterization and numerical modeling, advances the understanding of mechanical behavior and damage evolution under dynamic tension, providing a foundation for more reliable design strategies in UHPC structures subjected to extreme loading scenarios.
{"title":"Tensile behavior of UHPC under high strain rates: Experimental and numerical analysis","authors":"Júlio Jorge Braga de Carvalho Nunes , Pablo Augusto Krahl , Flávio de Andrade Silva","doi":"10.1016/j.ijimpeng.2025.105581","DOIUrl":"10.1016/j.ijimpeng.2025.105581","url":null,"abstract":"<div><div>The demand for resilient materials in impact-prone structures has increased interest in UHPC reinforced with steel fibers. Known for its strength and energy absorption capacity, UHPC is a promising construction material that can be used under dynamic loading. However, a lack of tensile data at high strain rates (>100 s⁻¹) limits the development of predictive models and safe structural design. This study addresses this gap by investigating the strain-rate-sensitive tensile behavior of UHPC reinforced with smooth (SF) and hooked-end fibers (HF), using direct tension tests across a wide strain-rate range (quasi-static to ∼200 s⁻¹). Results demonstrate that, while matrix strength controls the first peak stress, fiber geometry governs post-cracking behavior, energy dissipation, and ductility. UHPC SF achieved up to 35 % higher second peak loads and 18–22 % greater dynamic toughness than UHPC HF, reaching 674 kJ/m³ at 195 s⁻¹. In contrast, UHPC HF reached higher maximum peak loads (up to 32 kN) and more stable first-peak responses, but suffered abrupt post-peak stress drops, with toughness values limited to ∼572 kJ/m³. At higher strain levels, UHPC SF benefited from its uniform fiber distribution and frictional pull-out, while UHPC HF relied on mechanical anchorage that was less effective beyond ∼100 s⁻¹. The Dynamic Increase Factor (DIF) for peak load ranged from 2.7 to 4.2 for UHPC HF and from 3.3 to 3.9 for UHPC SF, significantly exceeding by up to 40 % the typical DIF range (1.5–3.0) reported for conventional concretes. Ultimate strain reached up to 4.5 % at 195 s⁻¹, with UHPC SF exhibiting a more stable strain evolution, while UHPC HF showed sudden cracking and steeper load drops. This behavior highlights the crucial role of fiber bridging in absorbing high-velocity impacts. This comprehensive experimental campaign also supported the calibration of a numerical simulation by the Concrete Damage Plasticity (CDP) model with strain rate dependence, which reproduced the key post-peak features of both UHPCs and predicted peak loads with less than 8 % deviation across the entire strain-rate range, including interpolated intervals lacking direct experimental data. Numerical predictions aligned with experimental DIF trends, confirming the robustness of the model for dynamic tensile loading. In addition, the predictive model for DIF captured experimental behavior across all strain-rate ranges, confirming its applicability for UHPC under extreme dynamic loading. This integrative approach, combining mechanical characterization and numerical modeling, advances the understanding of mechanical behavior and damage evolution under dynamic tension, providing a foundation for more reliable design strategies in UHPC structures subjected to extreme loading scenarios.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105581"},"PeriodicalIF":5.1,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529216","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 : 2025-11-08DOI: 10.1016/j.ijimpeng.2025.105584
Guocong Liang , Huawei Li , Wensu Chen , Hong Hao
Reinforced concrete (RC) beams are susceptible to negative bending moment (NBM) damage near supports under impact loads from various sources such as falling debris. This damage mode, caused by upward inertia forces, can severely compromise structural integrity, yet its quantitative prediction remains challenging due to the complex dynamic interactions. To date, the impact force profile characteristics (e.g., peak force and duration) and structural parameters (e.g., beam span and reinforcement ratio) that influence the dynamic response of RC beams have been extensively investigated. However, the relationship between the frequency contents of impact forces that excite higher-order response modes and the severity of NBM damage has received limited attention. In this study, the initiation and development mechanisms of NBM damage of RC beams are investigated. Using validated numerical models and Fast Fourier Transform analysis, it is found that the high-frequency components of the primary impact pulse that sufficiently excite the high vibration modes govern NBM damage severity. The larger spectral amplitude of impact force at corresponding frequencies of high vibration modes of beams induces more severe NBM damage. Larger impact force with shorter impulse duration results in a wider impact force frequency band, which in turn enhances the excitation of high-order modes and intensifies the NBM damage severity. A damage assessment method is developed based on spectral amplitudes of impact force at beam modal frequencies to quantitatively assess the severity of NBM damage in RC beams. The proposed framework provides a practical and effective tool for impact damage assessment of RC beams.
{"title":"Impact force frequency characteristics and their influence on damage modes of reinforced concrete beams","authors":"Guocong Liang , Huawei Li , Wensu Chen , Hong Hao","doi":"10.1016/j.ijimpeng.2025.105584","DOIUrl":"10.1016/j.ijimpeng.2025.105584","url":null,"abstract":"<div><div>Reinforced concrete (RC) beams are susceptible to negative bending moment (NBM) damage near supports under impact loads from various sources such as falling debris. This damage mode, caused by upward inertia forces, can severely compromise structural integrity, yet its quantitative prediction remains challenging due to the complex dynamic interactions. To date, the impact force profile characteristics (e.g., peak force and duration) and structural parameters (e.g., beam span and reinforcement ratio) that influence the dynamic response of RC beams have been extensively investigated. However, the relationship between the frequency contents of impact forces that excite higher-order response modes and the severity of NBM damage has received limited attention. In this study, the initiation and development mechanisms of NBM damage of RC beams are investigated. Using validated numerical models and Fast Fourier Transform analysis, it is found that the high-frequency components of the primary impact pulse that sufficiently excite the high vibration modes govern NBM damage severity. The larger spectral amplitude of impact force at corresponding frequencies of high vibration modes of beams induces more severe NBM damage. Larger impact force with shorter impulse duration results in a wider impact force frequency band, which in turn enhances the excitation of high-order modes and intensifies the NBM damage severity. A damage assessment method is developed based on spectral amplitudes of impact force at beam modal frequencies to quantitatively assess the severity of NBM damage in RC beams. The proposed framework provides a practical and effective tool for impact damage assessment of RC beams.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105584"},"PeriodicalIF":5.1,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528629","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 : 2025-11-06DOI: 10.1016/j.ijimpeng.2025.105580
Hu Zhou , Ange Lu , Cheng Zheng , Xiangshao Kong , Weiguo Wu
Cased charges are usually simplified as equivalent bare charges to characterize the energy dissipation and conversion caused by fragmentation and initial kinetic energy of metal casing under the driven force from inner detonation pressure. However, this conventional simplification method inherently neglects the afterburning effects of detonation products, introducing significant risks when applying cased charge analytical models to confined explosions. In this paper, three different configurations of cased charge were employed to investigate the energy release characteristic in confined explosion scenarios experimentally and numerically. In addition, comparative analyses were performed between bare charges and cased charges. The test results reveal that the initial peak overpressure of cased charge was significantly lower than that of the bare charge, but the quasi-static pressures were very close to each other, maintaining differences within 6 %. Numerical simulations employing the Smooth Particle Hydrodynamics (SPH) method were conducted to quantify the energy dissipation caused by casing fragmentation. Based on detonation energy conservation principles, equivalent bare charges with mass reductions of approximately 30 % compared to the initial cased charges were derived. However, pressure load analysis demonstrates substantial discrepancies exceeding 50 % in quasi-static pressure predictions between equivalent bare charges and cased charge configurations. To address this limitation, a reactive flow-based model was developed, explicitly incorporating chemical reactions and casing-product interactions. The proposed model achieved excellent agreement with experimental pressure histories in both temporal evolution and magnitude. Furthermore, a two-phase pressure load simplification framework was established based on pressure distribution and evolution patterns, which successfully reconciled with dynamic responses of target plate recorded in experiments. Furthermore, the critical role of quasi-static pressure in governing structural dynamic responses within confined spaces was identified through numerical analysis.
{"title":"Study on blast loading from cased charges in confined spaces using reactive flow modelling of afterburning","authors":"Hu Zhou , Ange Lu , Cheng Zheng , Xiangshao Kong , Weiguo Wu","doi":"10.1016/j.ijimpeng.2025.105580","DOIUrl":"10.1016/j.ijimpeng.2025.105580","url":null,"abstract":"<div><div>Cased charges are usually simplified as equivalent bare charges to characterize the energy dissipation and conversion caused by fragmentation and initial kinetic energy of metal casing under the driven force from inner detonation pressure. However, this conventional simplification method inherently neglects the afterburning effects of detonation products, introducing significant risks when applying cased charge analytical models to confined explosions. In this paper, three different configurations of cased charge were employed to investigate the energy release characteristic in confined explosion scenarios experimentally and numerically. In addition, comparative analyses were performed between bare charges and cased charges. The test results reveal that the initial peak overpressure of cased charge was significantly lower than that of the bare charge, but the quasi-static pressures were very close to each other, maintaining differences within 6 %. Numerical simulations employing the Smooth Particle Hydrodynamics (SPH) method were conducted to quantify the energy dissipation caused by casing fragmentation. Based on detonation energy conservation principles, equivalent bare charges with mass reductions of approximately 30 % compared to the initial cased charges were derived. However, pressure load analysis demonstrates substantial discrepancies exceeding 50 % in quasi-static pressure predictions between equivalent bare charges and cased charge configurations. To address this limitation, a reactive flow-based model was developed, explicitly incorporating chemical reactions and casing-product interactions. The proposed model achieved excellent agreement with experimental pressure histories in both temporal evolution and magnitude. Furthermore, a two-phase pressure load simplification framework was established based on pressure distribution and evolution patterns, which successfully reconciled with dynamic responses of target plate recorded in experiments. Furthermore, the critical role of quasi-static pressure in governing structural dynamic responses within confined spaces was identified through numerical analysis.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105580"},"PeriodicalIF":5.1,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528632","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 : 2025-11-05DOI: 10.1016/j.ijimpeng.2025.105577
Yi Xiao , Weiqing Zhu , Tangjie Wang , Timon Rabczuk
This study develops a novel coupled macro‑meso analytical framework that couples structural response with localized mesoscopic damage evolution, providing a unified approach to investigate the multiscale damage evolution mechanism within concrete components during contact explosion. Within this framework, the propagation of blast stress waves and the resulting internal stress distributions are analyzed at the macro scale; the transitions of local stress states and corresponding meso‑scale damage mechanisms are examined at the meso‑scale. The effects of aggregate density, shape, and distribution on the local damage characteristics of concrete are further examined. Results show that the stress gradient of concrete near the blast center and free surface is steep along the incident direction and shallow laterally, gradually decreasing towards the interior of the component. Depending on the stress state, five typical local failure modes of concrete are identified: progressive crushing, overall collapse, crack-induced damage, internal spalling, and surface spalling. Aggregate characteristics affect concrete damage differently under various damage modes, showing a significant influence in the crack-induced and spalling zones but only a limited effect in the progressive-crushing zone. This work provides a comprehensive multiscale understanding of internal damage mechanisms of concrete components under contact explosion, thereby contributing to the rational design of blast-resistant structures.
{"title":"Damage evolution mechanism in concrete components under contact explosion: A coupled macro-meso perspective","authors":"Yi Xiao , Weiqing Zhu , Tangjie Wang , Timon Rabczuk","doi":"10.1016/j.ijimpeng.2025.105577","DOIUrl":"10.1016/j.ijimpeng.2025.105577","url":null,"abstract":"<div><div>This study develops a novel coupled macro‑meso analytical framework that couples structural response with localized mesoscopic damage evolution, providing a unified approach to investigate the multiscale damage evolution mechanism within concrete components during contact explosion. Within this framework, the propagation of blast stress waves and the resulting internal stress distributions are analyzed at the macro scale; the transitions of local stress states and corresponding meso‑scale damage mechanisms are examined at the meso‑scale. The effects of aggregate density, shape, and distribution on the local damage characteristics of concrete are further examined. Results show that the stress gradient of concrete near the blast center and free surface is steep along the incident direction and shallow laterally, gradually decreasing towards the interior of the component. Depending on the stress state, five typical local failure modes of concrete are identified: progressive crushing, overall collapse, crack-induced damage, internal spalling, and surface spalling. Aggregate characteristics affect concrete damage differently under various damage modes, showing a significant influence in the crack-induced and spalling zones but only a limited effect in the progressive-crushing zone. This work provides a comprehensive multiscale understanding of internal damage mechanisms of concrete components under contact explosion, thereby contributing to the rational design of blast-resistant structures.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105577"},"PeriodicalIF":5.1,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528634","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 : 2025-11-05DOI: 10.1016/j.ijimpeng.2025.105579
Xue Zhang , Wenzheng Xu , Yulong Yang , Xiaolong Chang , Ningxin Ma , Shuying Lan , Yuhan Cui , Yunlong Xia , Sinuo Xin , Congcong Zhang , Boyang Zhang
To simulate the actual deceleration environment of the projectile-borne charge during the penetration of multi-layered hard targets, a multi-impact test method was designed based on the light gas gun test device for the penetration of concrete by projectile-borne charge. By adjusting the length of the steel pillar behind the charge, different deceleration environments for PBX were achieved. This allows the axial compression and density change rate obtained from the light gas gun tests to be equivalent to the artillery penetration test results. Building on this, multiple impact tests were conducted under different deceleration levels. Using a viscoelastic-plastic constitutive model and the LS-DYNA finite element software, multi-impact tests under different deceleration conditions were simulated. Moreover, the simulation results are consistent with the light gas gun test results. Stress curves, strain curves, and the density variation curve of the charge during each impact, which could not be measured in the experiments, were obtained. Through analysis, the dynamic response patterns of the charge under multiple impacts in different deceleration environments were obtained. The research results are of great significance for understanding the safety and structural stability of PBX under multi-impact environments.
{"title":"Study on the dynamic mechanical properties of PBX under multiple impact environments","authors":"Xue Zhang , Wenzheng Xu , Yulong Yang , Xiaolong Chang , Ningxin Ma , Shuying Lan , Yuhan Cui , Yunlong Xia , Sinuo Xin , Congcong Zhang , Boyang Zhang","doi":"10.1016/j.ijimpeng.2025.105579","DOIUrl":"10.1016/j.ijimpeng.2025.105579","url":null,"abstract":"<div><div>To simulate the actual deceleration environment of the projectile-borne charge during the penetration of multi-layered hard targets, a multi-impact test method was designed based on the light gas gun test device for the penetration of concrete by projectile-borne charge. By adjusting the length of the steel pillar behind the charge, different deceleration environments for PBX were achieved. This allows the axial compression and density change rate obtained from the light gas gun tests to be equivalent to the artillery penetration test results. Building on this, multiple impact tests were conducted under different deceleration levels. Using a viscoelastic-plastic constitutive model and the LS-DYNA finite element software, multi-impact tests under different deceleration conditions were simulated. Moreover, the simulation results are consistent with the light gas gun test results. Stress curves, strain curves, and the density variation curve of the charge during each impact, which could not be measured in the experiments, were obtained. Through analysis, the dynamic response patterns of the charge under multiple impacts in different deceleration environments were obtained. The research results are of great significance for understanding the safety and structural stability of PBX under multi-impact environments.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105579"},"PeriodicalIF":5.1,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528631","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 : 2025-11-03DOI: 10.1016/j.ijimpeng.2025.105567
Shushu Zhao, Jianguo Ning, Xiangzhao Xu
In this study, projectile penetration into a concrete/rock double-layer target is studied experimentally. The influence of interfacial reflected and transmitted waves on the perforation performance of double-layer targets is studied using the one-dimensional stress wave propagation theory. The perforation mechanism of double-layer targets is obtained by combining the principles of energy conservation and minimum potential energy. Based on these, a theoretical model is established to analyze the penetration behavior of the double-layered target subjected to rigid projectile loading. The established model is verified using the experimental data obtained from this study and other published literature. The results show that the prediction results of the present model are consistent with the experimental data at different initial penetration velocities. A comparative analysis of the present model with several previous penetration prediction models reveals its substantial advantages in terms of accuracy and applicability. The model can effectively predict the penetration performance of concrete/rock double-layer targets under different penetration velocities.
{"title":"Analysis model of double-layer targets of projectile penetration into concrete/rock considering interface effects","authors":"Shushu Zhao, Jianguo Ning, Xiangzhao Xu","doi":"10.1016/j.ijimpeng.2025.105567","DOIUrl":"10.1016/j.ijimpeng.2025.105567","url":null,"abstract":"<div><div>In this study, projectile penetration into a concrete/rock double-layer target is studied experimentally. The influence of interfacial reflected and transmitted waves on the perforation performance of double-layer targets is studied using the one-dimensional stress wave propagation theory. The perforation mechanism of double-layer targets is obtained by combining the principles of energy conservation and minimum potential energy. Based on these, a theoretical model is established to analyze the penetration behavior of the double-layered target subjected to rigid projectile loading. The established model is verified using the experimental data obtained from this study and other published literature. The results show that the prediction results of the present model are consistent with the experimental data at different initial penetration velocities. A comparative analysis of the present model with several previous penetration prediction models reveals its substantial advantages in terms of accuracy and applicability. The model can effectively predict the penetration performance of concrete/rock double-layer targets under different penetration velocities.</div></div>","PeriodicalId":50318,"journal":{"name":"International Journal of Impact Engineering","volume":"209 ","pages":"Article 105567"},"PeriodicalIF":5.1,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145468510","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}
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