Pub Date : 2021-10-18DOI: 10.1177/20414196211052062
R. Critchley, R. Hazael, K. Bhatti, D. Wood, A. Peare, Steve Johnson, T. Temple
Protection of critical infrastructure in an urban environment is a challenging task, specifically against the vehicle bourne improvised explosive device threat. To design infrastructure to withstand this evolving threat, novel solutions and advanced materials need to be developed. One such material of interest are auxetics. This study experimentally analysed the mitigation of blast response of auxetic re-entrant honeycomb structures, with geometries varying between −ve 30° and +ve 30° using additive manufacturing (3D printing) techniques and non-explosive loading via shock tube. Re-entrant auxetic structures (−ve 15°) exhibited repeatable blast mitigation of 23% and reduced the transmitted pressure and impulse of the blast wave. Further highlighting their potential application as a protective measure to enhance a structures blast survivability.
保护城市环境中的关键基础设施是一项具有挑战性的任务，特别是针对车载简易爆炸装置的威胁。为了设计能够抵御这种不断变化的威胁的基础设施，需要开发新的解决方案和先进的材料。其中一种有趣的材料是助生剂。本研究利用增材制造(3D打印)技术和通过激波管进行非爆炸加载，实验分析了几何形状在- ve 30°和+ve 30°之间变化的消声再入蜂窝结构的爆炸响应缓解。重新进入的辅助结构(- ve 15°)显示出23%的可重复爆炸缓解，并降低了冲击波的传递压力和脉冲。进一步强调了其作为提高建筑物爆炸生存能力的保护措施的潜在应用。
{"title":"Blast mitigation using polymeric 3D printed auxetic re-entrant honeycomb structures: A preliminary study","authors":"R. Critchley, R. Hazael, K. Bhatti, D. Wood, A. Peare, Steve Johnson, T. Temple","doi":"10.1177/20414196211052062","DOIUrl":"https://doi.org/10.1177/20414196211052062","url":null,"abstract":"Protection of critical infrastructure in an urban environment is a challenging task, specifically against the vehicle bourne improvised explosive device threat. To design infrastructure to withstand this evolving threat, novel solutions and advanced materials need to be developed. One such material of interest are auxetics. This study experimentally analysed the mitigation of blast response of auxetic re-entrant honeycomb structures, with geometries varying between −ve 30° and +ve 30° using additive manufacturing (3D printing) techniques and non-explosive loading via shock tube. Re-entrant auxetic structures (−ve 15°) exhibited repeatable blast mitigation of 23% and reduced the transmitted pressure and impulse of the blast wave. Further highlighting their potential application as a protective measure to enhance a structures blast survivability.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"469 - 486"},"PeriodicalIF":2.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46101052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-07DOI: 10.1177/20414196211048911
Hani Mahdavi Talaromi, Farhad Sakhaee
Numerical models have been used recently to analyze concrete structures subjected to high-impulsive loads. A material model that can well capture the mechanical behaviors is crucial to obtain reliable results. Present study, focused on reinforced concrete slab as a major load carrying element of the RC structures under blast loading. By performing several simulations in popular and powerful concrete constitutive models, including concrete damage R3, HJC, CSCM, and Winfrith the accuracy of these models was investigated. Maximum deflections have been compared with each other and expanded further to compare with experiments. Result showed all models have an acceptable accuracy in estimating maximum slab deflection. Concrete Damage R3 presented the highest accuracy. HJC has the second rank and CSCM and Winfrith have the third and the fourth places, respectively. HJC needed the minimum computation time. CSCM had minimum input parameters but includes maximum calculation time. Winfrith had the lowest accuracy, however this model presented very conservative results. Uniaxial compressive and tensile stress-strain curves showed that the models which presented higher values of strength, evaluated lower maximum values of deflection.
{"title":"Evaluation and comparison of concrete constitutive models in numerical simulation of reinforced concrete slabs under blast load","authors":"Hani Mahdavi Talaromi, Farhad Sakhaee","doi":"10.1177/20414196211048911","DOIUrl":"https://doi.org/10.1177/20414196211048911","url":null,"abstract":"Numerical models have been used recently to analyze concrete structures subjected to high-impulsive loads. A material model that can well capture the mechanical behaviors is crucial to obtain reliable results. Present study, focused on reinforced concrete slab as a major load carrying element of the RC structures under blast loading. By performing several simulations in popular and powerful concrete constitutive models, including concrete damage R3, HJC, CSCM, and Winfrith the accuracy of these models was investigated. Maximum deflections have been compared with each other and expanded further to compare with experiments. Result showed all models have an acceptable accuracy in estimating maximum slab deflection. Concrete Damage R3 presented the highest accuracy. HJC has the second rank and CSCM and Winfrith have the third and the fourth places, respectively. HJC needed the minimum computation time. CSCM had minimum input parameters but includes maximum calculation time. Winfrith had the lowest accuracy, however this model presented very conservative results. Uniaxial compressive and tensile stress-strain curves showed that the models which presented higher values of strength, evaluated lower maximum values of deflection.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"80 - 98"},"PeriodicalIF":2.0,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49070172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-07DOI: 10.1177/20414196211048910
S. M. Anas, M. Alam, M. Umair
Weak political systems and poor governance in certain developing countries are found to have a war-like environment where structures are being targeted by blasts and bombs. Industrial blasts due to frail know-how and mishandlings are also quite common. Recent accidental explosions like that occurred at the Beirut Port, Lebanon (August 2020); ammunition depot in the outskirt of the Ryazan City of Russia (November 2020) are of concern for the safety of adjacent building infrastructure and their users. Such intense loading events cause damage to certain elements of a structure which may result in disproportionate or progressive collapse. It necessitates a clear understanding of the phenomenon of the blast and extreme loads induced out of it, and response of the target structure under such loadings. In this study, the state of research on air-blast and ground shockwave parameters, shallow underground blasting, and on the ground and buried shallow blast-resistant shelters are presented. The phenomenon of the self-Mach-reflection of the explosion, loading parameters and empirical blast models available in the open literature followed by the damage criteria for the buildings subjected to the underground blasting and available peak particle velocity (PPV) prediction models have been discussed. To make the application of advanced materials such as fibrous concrete, ultra-high performance concrete, FRP composites, etc., it is important to comprehend the existing blast/shock-resistant shelters and their response under such loading. The shelters are primarily designed by incorporating features of the materials like high degree of deformability/ductility, use of the shock-isolation panels and the mechanism for controlling crack formations. Finally, conclusions and recommendations for future studies are summarised. This paper presents prospects to engineers, town planners, researchers, policymakers and members of the core drafting sectional committees to understand the phenomenon of the blast and extreme loads induced out of it.
{"title":"Air-blast and ground shockwave parameters, shallow underground blasting, on the ground and buried shallow underground blast-resistant shelters: A review","authors":"S. M. Anas, M. Alam, M. Umair","doi":"10.1177/20414196211048910","DOIUrl":"https://doi.org/10.1177/20414196211048910","url":null,"abstract":"Weak political systems and poor governance in certain developing countries are found to have a war-like environment where structures are being targeted by blasts and bombs. Industrial blasts due to frail know-how and mishandlings are also quite common. Recent accidental explosions like that occurred at the Beirut Port, Lebanon (August 2020); ammunition depot in the outskirt of the Ryazan City of Russia (November 2020) are of concern for the safety of adjacent building infrastructure and their users. Such intense loading events cause damage to certain elements of a structure which may result in disproportionate or progressive collapse. It necessitates a clear understanding of the phenomenon of the blast and extreme loads induced out of it, and response of the target structure under such loadings. In this study, the state of research on air-blast and ground shockwave parameters, shallow underground blasting, and on the ground and buried shallow blast-resistant shelters are presented. The phenomenon of the self-Mach-reflection of the explosion, loading parameters and empirical blast models available in the open literature followed by the damage criteria for the buildings subjected to the underground blasting and available peak particle velocity (PPV) prediction models have been discussed. To make the application of advanced materials such as fibrous concrete, ultra-high performance concrete, FRP composites, etc., it is important to comprehend the existing blast/shock-resistant shelters and their response under such loading. The shelters are primarily designed by incorporating features of the materials like high degree of deformability/ductility, use of the shock-isolation panels and the mechanism for controlling crack formations. Finally, conclusions and recommendations for future studies are summarised. This paper presents prospects to engineers, town planners, researchers, policymakers and members of the core drafting sectional committees to understand the phenomenon of the blast and extreme loads induced out of it.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"99 - 139"},"PeriodicalIF":2.0,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41791837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-06DOI: 10.1177/20414196211042036
B. Terranova, Len Schwer, A. Whittaker
Data from the Tsubota et al. (1993) experiments provided the basis for a numerical study that investigated the impact response of steel-plate lined, reinforced concrete panels using the SPH formulation in LS-DYNA. The simulated tests involved 50 mm (1.97 in), 70 mm (2.76 in), and 90 mm (3.54 in) thick reinforced concrete (RC) panels with steel liners and one 50-mm thick benchmark RC panel. Three of the five panels had a steel liner attached to the back face and one had a steel liner on both faces. The panels were normally impacted by a 39.6 mm (1.56 in) diameter projectile at a velocity of 170 m/s (6693 in/s). Reasonable predictions of observed damage, including perforation, liner fracture or bulging, and concrete scabbing were achieved using the MAT072R3 concrete material model. The effectiveness of adding steel liners to a concrete panel to prevent perforation and scabbing resulting from projectile impact was investigated using the numerical model and MAT072R3. Installing a steel liner on the back face of a panel, with a reinforcement ratio equal to that of the internal reinforcement, is an effective method to mitigate scabbing but has little effect on perforation resistance.
{"title":"Simulation of projectile impact on steel plate-lined, reinforced concrete panels using the smooth particle hydrodynamics formulation","authors":"B. Terranova, Len Schwer, A. Whittaker","doi":"10.1177/20414196211042036","DOIUrl":"https://doi.org/10.1177/20414196211042036","url":null,"abstract":"Data from the Tsubota et al. (1993) experiments provided the basis for a numerical study that investigated the impact response of steel-plate lined, reinforced concrete panels using the SPH formulation in LS-DYNA. The simulated tests involved 50 mm (1.97 in), 70 mm (2.76 in), and 90 mm (3.54 in) thick reinforced concrete (RC) panels with steel liners and one 50-mm thick benchmark RC panel. Three of the five panels had a steel liner attached to the back face and one had a steel liner on both faces. The panels were normally impacted by a 39.6 mm (1.56 in) diameter projectile at a velocity of 170 m/s (6693 in/s). Reasonable predictions of observed damage, including perforation, liner fracture or bulging, and concrete scabbing were achieved using the MAT072R3 concrete material model. The effectiveness of adding steel liners to a concrete panel to prevent perforation and scabbing resulting from projectile impact was investigated using the numerical model and MAT072R3. Installing a steel liner on the back face of a panel, with a reinforcement ratio equal to that of the internal reinforcement, is an effective method to mitigate scabbing but has little effect on perforation resistance.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"65 - 79"},"PeriodicalIF":2.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42294892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-06DOI: 10.1177/20414196211043537
M. Stewart
There can be significant uncertainty and variability with explosive blast loading. Standards and codes of practice are underpinned by reliability-based principles, and there is little reason not to apply these to explosive blast loading. This paper develops a simplified approach where regression equations may be used to predict the probabilistic model of airblast variability and associated reliability-based design load factors (or RBDFs) for all combinations of range, explosive mass and model errors. These models are applicable to (i) hemispherical surface bursts, and (ii) spherical free-air bursts. The benefit of this simplified approach is that the equations can be easily programed into a spreadsheet, computer code or other numerical methods. There is no need for any Monte-Carlo or other probabilistic calculations. Examples then illustrate how model error, range and explosive mass uncertainty and variability affect the variability of pressure and impulse, which in turn affect the damage assessment of residential construction.
{"title":"Simplified calculation of airblast variability and reliability-based design load factors for spherical air burst and hemispherical surface burst explosions","authors":"M. Stewart","doi":"10.1177/20414196211043537","DOIUrl":"https://doi.org/10.1177/20414196211043537","url":null,"abstract":"There can be significant uncertainty and variability with explosive blast loading. Standards and codes of practice are underpinned by reliability-based principles, and there is little reason not to apply these to explosive blast loading. This paper develops a simplified approach where regression equations may be used to predict the probabilistic model of airblast variability and associated reliability-based design load factors (or RBDFs) for all combinations of range, explosive mass and model errors. These models are applicable to (i) hemispherical surface bursts, and (ii) spherical free-air bursts. The benefit of this simplified approach is that the equations can be easily programed into a spreadsheet, computer code or other numerical methods. There is no need for any Monte-Carlo or other probabilistic calculations. Examples then illustrate how model error, range and explosive mass uncertainty and variability affect the variability of pressure and impulse, which in turn affect the damage assessment of residential construction.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"144 - 160"},"PeriodicalIF":2.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41752447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.1177/2041419618758825
S. Abramsky, L. Aceto, P. Aczel, R. Amadio, Magnus Andersson, A. Baltag, Jonas Barklund, Michael Barr, Gilles Bar
Samson Abramsky Luca Aceto Peter Aczel Roberto Amadio Magnus Andersson Alexandru Baltag Jonas Barklund Michael Barr Gilles Bar-the Sergey Berezin Ulrich Berger G.M. Bierman Marcus Bjareland Jens Blanck A. Bockmayr Ahmed Bouajjan Gerard Boudol Julian Bradfield Torben Brauner Andrei Broder Antonio Bucciarelli Olaf Burkart Ilaria Castellani Luca Cattani Adam Cichon Ed Clarke W.F. Clocksin A.B. Compagnoni Thierry Coquand Tristan Crolard Pierre-Louis Curien Norman Danner Rene David Pierre Deransart Nachum Dershowitz Roberto Di Cosmo Gilles Dowek Thomas Drakengren R. Drechsler Stefan Dziembowski Thomas Ehrhard Kousha Etessami Mike Four-man Alan Frieze Ken-etsu Fujita Kim G. Larsen Harald Canzinger Philippa Gardner Simon Gay Herman Geuvers Giorgio Ghelli Rob van Glabbeek A.D. Gordon Michal Grabowski P. W. Grant Tim Griffin Philippe de Groote Stephane Grumbach Dirk van Gucht Vineet Gupta Therese Hardin Michael Hedberg Nevin Heintze Lauri Hella Fritz Henglein Hugo Herbelin Jane Hillston J.R. Hindley Martin Hofmann Furio Honsell Doug Howe Lorenz Huelsbergen Ullrich Hustadt Martin Hyland Anna Ingolfsdottir Mark Jerrum Johan Jeuring Somesh Jha Marcin Jurdzinski Richard Kennaway Helene Kirchner Nils Klarlund
Samson Abramsky Luca Aceto Peter Aczel Roberto Amadio Magnus Andersson Alexandru Baltag Jonas Barklund Michael Barr Gilles Bar Sergey Berezin Ulrich Berger G.M.Bierman Marcus Bjarland Jens Blank A。Bockmayr Ahmed Bouajjan Gerard Boudol Julian Bradfield Torben Brauner Andrei Broder Antonio Bucciarelli Olaf Burkart Ilaria Castellani Luca Cattani Adam Cichon Ed Clarke W.F.Clocksin A.B.Compagnoni Thierry Coquand Tristan Crolard Pierre Louis Curien Norman Danner Rene David Pierre Deransart Nachum Dershowitz Roberto Di Cosmo Gilles Dowek Thomas Drakengren R。Drechsler Stefan Dziembowski Thomas Ehrhard Kousha Etessami Mike四人Alan Frieze Ken etsu Fujita Kim G.Larsen Harald Canzinger Philippa Gardner Simon Gay Herman Geuvers Giorgio Ghelli Rob van Glabeek A.D.Gordon Michal Grabowski P.W。Grant Tim Griffin Philippe de Groote Stephane Grumbach Dirk van Gucht Vineet Gupta Therese Hardin Michael Hedberg Nevin Heintze Lauri Hella Fritz Henglein Hugo Herbelin Jane Hillston J.R.Hindley Martin Hofmann Furio Honsell Doug Howe Lorenz Huelsbergen Ullrich Hustadt Martin Hyland Anna Ingolfsdotir Mark Jerrum Johan Jeuring Somesh Jha Marcin Jurdzinski Richard Kennaway Helene Kirchner Nils克拉伦德
{"title":"Reviewers List","authors":"S. Abramsky, L. Aceto, P. Aczel, R. Amadio, Magnus Andersson, A. Baltag, Jonas Barklund, Michael Barr, Gilles Bar","doi":"10.1177/2041419618758825","DOIUrl":"https://doi.org/10.1177/2041419618758825","url":null,"abstract":"Samson Abramsky Luca Aceto Peter Aczel Roberto Amadio Magnus Andersson Alexandru Baltag Jonas Barklund Michael Barr Gilles Bar-the Sergey Berezin Ulrich Berger G.M. Bierman Marcus Bjareland Jens Blanck A. Bockmayr Ahmed Bouajjan Gerard Boudol Julian Bradfield Torben Brauner Andrei Broder Antonio Bucciarelli Olaf Burkart Ilaria Castellani Luca Cattani Adam Cichon Ed Clarke W.F. Clocksin A.B. Compagnoni Thierry Coquand Tristan Crolard Pierre-Louis Curien Norman Danner Rene David Pierre Deransart Nachum Dershowitz Roberto Di Cosmo Gilles Dowek Thomas Drakengren R. Drechsler Stefan Dziembowski Thomas Ehrhard Kousha Etessami Mike Four-man Alan Frieze Ken-etsu Fujita Kim G. Larsen Harald Canzinger Philippa Gardner Simon Gay Herman Geuvers Giorgio Ghelli Rob van Glabbeek A.D. Gordon Michal Grabowski P. W. Grant Tim Griffin Philippe de Groote Stephane Grumbach Dirk van Gucht Vineet Gupta Therese Hardin Michael Hedberg Nevin Heintze Lauri Hella Fritz Henglein Hugo Herbelin Jane Hillston J.R. Hindley Martin Hofmann Furio Honsell Doug Howe Lorenz Huelsbergen Ullrich Hustadt Martin Hyland Anna Ingolfsdottir Mark Jerrum Johan Jeuring Somesh Jha Marcin Jurdzinski Richard Kennaway Helene Kirchner Nils Klarlund","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"9 1","pages":"118 - 118"},"PeriodicalIF":2.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/2041419618758825","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47205135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-31DOI: 10.1177/20414196211041137
K. Ahmed, A. Malik
The detonation of an energetic material (EM) is manifested in the form of blast wave, fragmentation of casing material, and thermal effects. These effects are very destructive and cause injuries-being fatal-and structural damage as well. The attenuation of these effects is a prime focus. C4 explosive weighing 104 g was tested as surface burst. Peak overpressures of 1362 kPa and fireball radius of 0.65 m were measured. A multi-layer container comprised steel liner, Kevlar woven fabric, and laminated glass fiber reinforced polymer (GFRP) was developed and investigated to counter the combined blast, fragmentation, and thermal effects of EM detonation. Commercially available shaving foam was characterized and used as filling material inside the container. The foam bubbles have shown a good stability with time. The shaving foam quenched the fireball and afterburning reactions owing to rapid heat and momentum transfer mechanism. The containment system provided more than 80% overpressure reduction with respect to an equivalent open-air detonation and also restricted any escape to lateral directions. Coupled Euler-ALE (Arbitrary Lagrangian-Eulerian) approach was employed to numerically simulate the blast wave parameters. A good agreement is obtained between the simulation and experimental results.
{"title":"Experimental investigations of the response of a portable container to blast, fragmentation, and thermal effects of energetic materials detonation","authors":"K. Ahmed, A. Malik","doi":"10.1177/20414196211041137","DOIUrl":"https://doi.org/10.1177/20414196211041137","url":null,"abstract":"The detonation of an energetic material (EM) is manifested in the form of blast wave, fragmentation of casing material, and thermal effects. These effects are very destructive and cause injuries-being fatal-and structural damage as well. The attenuation of these effects is a prime focus. C4 explosive weighing 104 g was tested as surface burst. Peak overpressures of 1362 kPa and fireball radius of 0.65 m were measured. A multi-layer container comprised steel liner, Kevlar woven fabric, and laminated glass fiber reinforced polymer (GFRP) was developed and investigated to counter the combined blast, fragmentation, and thermal effects of EM detonation. Commercially available shaving foam was characterized and used as filling material inside the container. The foam bubbles have shown a good stability with time. The shaving foam quenched the fireball and afterburning reactions owing to rapid heat and momentum transfer mechanism. The containment system provided more than 80% overpressure reduction with respect to an equivalent open-air detonation and also restricted any escape to lateral directions. Coupled Euler-ALE (Arbitrary Lagrangian-Eulerian) approach was employed to numerically simulate the blast wave parameters. A good agreement is obtained between the simulation and experimental results.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"45 - 64"},"PeriodicalIF":2.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44028018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-23DOI: 10.1177/20414196211038018
Senthil Kasilingam, M. Sethi, L. Pelecanos, N. Gupta
An evaluation of mitigation strategies of underground tunnels against explosions is important to the society. Therefore, a small scale tunnel was modeled against blast loading using finite element software ABAQUS. The inelastic behavior of concrete and steel bar has been incorporated through concrete damage plasticity model and Johnson-cook models respectively, available in ABAQUS. The Drucker-Prager model as well as acoustic infinite medium have been used to model the damage behavior of soil and tunnel respectively. The simulated results thus obtained from the present study were compared with the experimental results available in the literature and found in good agreement. Further, the simulations were carried to predict the damage intensity in tunnel in terms of acceleration, impulse velocity, displacement, and Mises stresses. There are many parameters which were taken into consideration to assess the mitigation strategies for the underground tunnels. The critical parameters include the influence of tunnel shapes, lining materials, lining thickness, burial depth of the tunnels, inclusion of a barrier in between the blast source-the tunnel and layered configuration of tunnel lining, and were considered to evaluate the mitigation strategy. It was concluded that the square shape of tunnel was most vulnerable as compared to circular and U-shaped tunnels. It was also concluded that plain concrete monolithic lining as well as layered configuration consisting of Dytherm foam layer between Steel Fiber reinforced Concrete layers, was found to be more vulnerable among the chosen lining materials. Also, the thickness of lining and burial depth of the tunnel found to be a significant role against blast loading.
{"title":"Mitigation strategies of underground tunnels against blast loading","authors":"Senthil Kasilingam, M. Sethi, L. Pelecanos, N. Gupta","doi":"10.1177/20414196211038018","DOIUrl":"https://doi.org/10.1177/20414196211038018","url":null,"abstract":"An evaluation of mitigation strategies of underground tunnels against explosions is important to the society. Therefore, a small scale tunnel was modeled against blast loading using finite element software ABAQUS. The inelastic behavior of concrete and steel bar has been incorporated through concrete damage plasticity model and Johnson-cook models respectively, available in ABAQUS. The Drucker-Prager model as well as acoustic infinite medium have been used to model the damage behavior of soil and tunnel respectively. The simulated results thus obtained from the present study were compared with the experimental results available in the literature and found in good agreement. Further, the simulations were carried to predict the damage intensity in tunnel in terms of acceleration, impulse velocity, displacement, and Mises stresses. There are many parameters which were taken into consideration to assess the mitigation strategies for the underground tunnels. The critical parameters include the influence of tunnel shapes, lining materials, lining thickness, burial depth of the tunnels, inclusion of a barrier in between the blast source-the tunnel and layered configuration of tunnel lining, and were considered to evaluate the mitigation strategy. It was concluded that the square shape of tunnel was most vulnerable as compared to circular and U-shaped tunnels. It was also concluded that plain concrete monolithic lining as well as layered configuration consisting of Dytherm foam layer between Steel Fiber reinforced Concrete layers, was found to be more vulnerable among the chosen lining materials. Also, the thickness of lining and burial depth of the tunnel found to be a significant role against blast loading.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"21 - 44"},"PeriodicalIF":2.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49330909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-16DOI: 10.1177/20414196211035486
M. Costas, Maisie Edwards-Mowforth, M. Kristoffersen, F. Teixeira-Dias, V. Brotan, Christian O. Paulsen, T. Børvik
Maraging steel is a low carbon steel known for its ultra high-strength after heat treatment. In combination with Additive Manufacturing (AM), the properties of maraging steel indicate potential to enable complex geometries and improved performance-to-weight ratios for ballistic protection. This study investigates the ballistic performance of AM maraging steel monolithic plates and profile panels fabricated by powder bed fusion. The mechanical properties of the maraging steel, both in the as-built state and after heat treatment, were revealed through quasi-static and dynamic tests in three different directions with respect to the build direction. Metallurgical studies were also conducted to investigate the microstructure of the material both before and after testing. The ballistic perforation resistance of the maraging steel samples was disclosed in a ballistic range by firing 7.62 mm APM2 bullets towards the different target configurations. Ballistic limit curves and velocities were obtained, demonstrating that the thickest heat-treated AM maraging steel plate has a particularly good potential for ballistic protection. The hard core of the armour piercing bullet broke in all tests and occasionally shattered during tests with heat-treated targets. However, due to the severe brittleness of the material, the targets showed significant fragmentation in some cases and most significantly for the profile panels.
马氏体时效钢是一种热处理后具有超高强度的低碳钢。与增材制造(AM)相结合，马氏体时效钢的特性表明了实现复杂几何形状和提高弹道防护性能重量比的潜力。研究了粉末床熔合制备的AM马氏体时效钢整体板和异型板的弹道性能。通过相对于铸态方向三个不同方向的准静态和动态试验，揭示了马氏体时效钢在铸态和热处理后的力学性能。还进行了冶金研究，以研究材料在测试前后的微观结构。通过对不同靶形的7.62 mm APM2子弹射击，揭示了马氏体时效钢样品在弹道范围内的抗弹道穿孔性能。得到了弹道极限曲线和速度，表明最厚的热处理AM马氏体时效钢板具有特别好的弹道防护潜力。穿甲弹的硬核在所有测试中都破裂了，在针对热处理目标的测试中偶尔也会破裂。然而，由于材料的严重脆性，目标在某些情况下显示出明显的碎片，最明显的是型材面板。
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Pub Date : 2021-08-08DOI: 10.1177/20414196211037702
Y. Vayig, Z. Rosenberg
A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.
{"title":"The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets","authors":"Y. Vayig, Z. Rosenberg","doi":"10.1177/20414196211037702","DOIUrl":"https://doi.org/10.1177/20414196211037702","url":null,"abstract":"A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":"13 1","pages":"3 - 20"},"PeriodicalIF":2.0,"publicationDate":"2021-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42239518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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