International Journal of Protective Structures最新文献_第9页

Physics-informed regularisation procedure in neural networks: An application in blast protection engineering 神经网络中的物理规则化过程：在防爆工程中的应用

IF 2

International Journal of Protective Structures Pub Date : 2022-04-13 DOI: 10.1177/20414196211073501

J. J. Pannell, S. Rigby, G. Panoutsos

{"title":"Physics-informed regularisation procedure in neural networks: An application in blast protection engineering","authors":"J. J. Pannell, S. Rigby, G. Panoutsos","doi":"10.1177/20414196211073501","DOIUrl":"https://doi.org/10.1177/20414196211073501","url":null,"abstract":"Machine learning offers the potential to enable probabilistic-based approaches to engineering design and risk mitigation. Application of such approaches in the field of blast protection engineering would allow for holistic and efficient strategies to protect people and structures subjected to the effects of an explosion. To achieve this, fast-running engineering models that provide accurate predictions of blast loading are required. This paper presents a novel application of a physics-guided regularisation procedure that enhances the generalisation ability of a neural network (PGNN) by implementing monotonic loss constraints to the objective function due to specialist prior knowledge of the problem domain. The PGNN is developed for prediction of specific impulse loading distributions on a rigid target following close-in detonation of a spherical mass of high explosive. The results are compared to those from a traditional neural network (NN) architecture and stress-tested through various data holdout approaches to evaluate its generalisation ability. In total the results show five statistically significant performance premiums, with four of these being achieved by the PGNN. This indicates that the proposed methodology can be used to improve the accuracy and physical consistency of machine learning approaches for blast load prediction.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48430290","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}

引用次数: 14

Mitigation of blast effects through novel energy-dissipating connectors 通过新型耗能连接器减轻爆炸影响

IF 2

International Journal of Protective Structures Pub Date : 2022-04-08 DOI: 10.1177/20414196221074058

M. Seica, J. Packer, M. Walker, M. Gow

{"title":"Mitigation of blast effects through novel energy-dissipating connectors","authors":"M. Seica, J. Packer, M. Walker, M. Gow","doi":"10.1177/20414196221074058","DOIUrl":"https://doi.org/10.1177/20414196221074058","url":null,"abstract":"Explosions generate overpressures that can cause irreparable damage to structures. For many buildings, especially critical infrastructure, continued operation after an explosive attack is essential. The use of energy-dissipating methods will enable the protection of a structure and occupants from a blast and permit the timely repair and re-occupation of the building after an event. The concept behind the system presented is the creation of panels that can be used as cladding for structures. The panels are connected to the main structure using energy-dissipating component assemblies around the panel edge. When subjected to a blast load the panels transfer the blast pressure through the assemblies, thereby reducing the forces transmitted to the underlying structure. After an event, the panels and energy-dissipating component assemblies can be replaced quickly and easily, allowing the building to be reoccupied in a short time after an attack. This study focuses on the characterization of energy-dissipating component assemblies using static and dynamic laboratory testing. A predictive theory, supported by a single degree of freedom model, is developed and a general evaluation method proposed. Further laboratory testing expands the characterization of behaviour of the assemblies through experiments, with a blast generator in tension tests and in simulated blast panel tests. The time histories developed from tension tests are then compared to examine the effect of loading rate. The investigations on blast panels also include a comparison with predictions to determine whether the latter can describe the global behaviour of the system. Lastly, the response of the energy-dissipating component assemblies is evaluated in full-scale field blast tests on cladding panels.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45424906","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}

引用次数: 0

Local failure resistance of polypropylene fiber reinforced concrete plates subjected to projectile impact 聚丙烯纤维混凝土板在弹丸冲击下的局部破坏抗力

IF 2

International Journal of Protective Structures Pub Date : 2022-04-03 DOI: 10.1177/20414196221078607

M. Beppu, Koki Mori, H. Ichino, Yoichiro Muroga

引用次数: 2

Time of arrival as a diagnostic for far-field high explosive blast waves 作为远场高爆震波诊断的到达时间

IF 2

International Journal of Protective Structures Pub Date : 2022-04-01 DOI: 10.1177/20414196211062923

Dain G. Farrimond, S. Rigby, S. Clarke, A. Tyas

{"title":"Time of arrival as a diagnostic for far-field high explosive blast waves","authors":"Dain G. Farrimond, S. Rigby, S. Clarke, A. Tyas","doi":"10.1177/20414196211062923","DOIUrl":"https://doi.org/10.1177/20414196211062923","url":null,"abstract":"The ability to accurately determine blast loading parameters will enable more fundamental studies on the sources of blast parameter variability and their influence on the magnitude and form of the loading itself. This will ultimately lead to a better fundamental understanding of blast wave behaviour, and will result in more efficient and effective protective systems and enhanced resilience of critical infrastructure. This article presents a study on time of arrival as a diagnostic for far-field high explosive blasts, and makes use of the results from a large number of historic tests and newly performed experiments where the propagating shock front was filmed using a high-speed video (HSV) camera. A new method for optical shock tracking of far-field blast tests is developed and validated, and full-field arrival time results are compared against those determined from the historic data recorded using traditional pressure gauges. Arrival time variability is shown to be considerably lower than peak pressure and peak specific impulse, and is shown to decrease exponentially with increasing scaled distance. Further, the method presented in this article using HSV cameras to determine arrival time yields further reductions in variability. Finally, it is demonstrated that the method can be used to accurately determine far-field TNT equivalence of high explosives.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46465992","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}

引用次数: 8

From impact of RC flat slabs in a building to its progressive collapse 从建筑物中钢筋混凝土平板的冲击到其逐渐倒塌

IF 2

International Journal of Protective Structures Pub Date : 2022-03-28 DOI: 10.1177/20414196221078024

D. Yankelevsky, Y. Karinski, D. Tsemakh, V. Feldgun

{"title":"From impact of RC flat slabs in a building to its progressive collapse","authors":"D. Yankelevsky, Y. Karinski, D. Tsemakh, V. Feldgun","doi":"10.1177/20414196221078024","DOIUrl":"https://doi.org/10.1177/20414196221078024","url":null,"abstract":"This paper presents a realistic model for the simulation of a progressive collapse scenario in a typical low-rise building that is constructed from RC flat slabs and supported by columns. The progressive collapse scenario starts after failure of the top slab connections, where the slab is falling downward and impacts with the slab below. This impact event is analyzed, and the dynamic failure of the impacted slab’s connections starts the progressive collapse event. Two different scenarios are identified, depending on the first slab damage condition prior to impact. The first scenario refers to an undamaged impacting slab where an elastic collision occurs with the slab below; in the second scenario, the first slab is damaged, and its collision with the slab below is plastic. In the first scenario, the impacting slab velocity drops to zero while its velocity is fully imparted to the impacted slab. In the second scenario, both slabs continue their motion jointly at a common velocity. In the subsequent impacts, the impacting slabs are a-priori damaged, hence plastic collisions occur. These impact occurrences are analyzed separately, depending on the number of impacting slabs involved, damage characteristics, and impact velocity. Due to the nature of the first impact, the first scenario is characterized by separate motion of the first impacting slab which is falling behind the other slabs. This slab gains speed until it meets the other falling slabs below at a certain altitude, and an intermediate collision occurs, not necessarily at a floor level. In the analyzed five-story building, the intermediate impact occurs after the third impact event, where the slabs are located slightly above the first story level. The intermediate impact elevates the velocity of the impacted slabs such that their impact with the first level slab is more severe and its motion toward hitting the ground level is faster.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66136083","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}

引用次数: 3

Progressive damage in pretensioned and reinforced concrete plates against repeated impacts 预应力和钢筋混凝土板在反复冲击下的渐进损伤

IF 2

International Journal of Protective Structures Pub Date : 2022-03-27 DOI: 10.1177/20414196221078025

Vimal Kumar, M. Iqbal, A. Mittal

{"title":"Progressive damage in pretensioned and reinforced concrete plates against repeated impacts","authors":"Vimal Kumar, M. Iqbal, A. Mittal","doi":"10.1177/20414196221078025","DOIUrl":"https://doi.org/10.1177/20414196221078025","url":null,"abstract":"This study is planned to explore the performance of pretensioned concrete (PC) plates under multiple impacts. A detailed investigation has been carried out on pretensioned concrete plates (0.8 × 0.8 m2) against drop impact. The plates prepared using Mix-40 and Mix-60 grade concrete have been induced with two different levels of initial prestress, that is, 1/10 and 1/5 (i.e. level-1 and level-2) times the strength of the concrete. The PC plates have been impacted by a falling impactor (2382 N) dropped from 0.5 m height. The response of those plates has been obtained and compared with the reference RC plates. The post-impact performance of the damaged plates has been further discovered by subsequently dropping the impactor multiple times from the identical height. The FE simulations of the problem have been carried out using Johnson-Holmquist-2 and metal-plasticity constitutive models for concrete and steel, respectively. The models have been initially verified with the experimental results available in literature, and subsequently the simulations for drop impact have been carried out. The simulation results are also compared with the results of drop impact experimentations performed. In general, both the pretensioned and reinforced concrete have witnessed flexural cracks at the beginning, such that pretensioned concrete witnessed lesser cracks compared to reinforced concrete. As the number of drops increased, one major splitting crack developed only in pretensioned concrete, whereas the reinforced concrete exhibited additional punching cracks. For a given concrete grade, the pretensioned concrete level-2 witnessed the smallest damage, minimal cracks, and also minimal spalling followed by the pretensioned concrete level-1 and reinforced concrete. The reinforced concrete absorbed the minimal impact energy followed by the pretensioned concrete level-1 and level-2 under the multiple impacts. The FE simulations predicted the impact force and reaction within 11.9 and 9.9% variation, respectively, with the corresponding experimental results.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46205265","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}

引用次数: 1

Experimental investigation of 3D-printed auxetic core sandwich structures under quasi-static and dynamic compression and bending loads 三维打印膨胀芯夹层结构在准静态和动态压缩和弯曲载荷下的实验研究

IF 2

International Journal of Protective Structures Pub Date : 2022-03-27 DOI: 10.1177/20414196221079366

İnci Türkoǧlu, Hasan Kasım, M. Yazıcı

{"title":"Experimental investigation of 3D-printed auxetic core sandwich structures under quasi-static and dynamic compression and bending loads","authors":"İnci Türkoǧlu, Hasan Kasım, M. Yazıcı","doi":"10.1177/20414196221079366","DOIUrl":"https://doi.org/10.1177/20414196221079366","url":null,"abstract":"Auxiliary metamaterials designed according to the Negative Poisson’s Ratio (NPR) property are exciting structures due to their high impact strength, impact energy absorption abilities, and different damage mechanisms. These good mechanical features are suitable for aviation, automotive, and protective construction applications. These structures, whose most significant disadvantages are production difficulties, have become easier to produce with the development of 3D production technology and have been the subject of many studies in recent years. In this presented study, two conventional core geometries and three different auxetic geometries, commonly used in sandwich structures, were designed and produced with 3D printer technology. The strength and energy absorption capabilities of prototype sandwich structures investigated experimentally under bending loads with static and dynamic compression. Except for the re-entrant (RE) type core, the auxetic core foam sandwich structures demonstrate higher rigidity and load-carrying capacity than classical sinusoidal corrugated (SC) core and honeycomb (HC) core sandwich structures under both quasi-static and impact-loaded compression and three-point bending experiments. Double arrowhead (DAH) and tetrachiral (TC) auxetic cores outperformed honeycomb core in terms of specific quasi-static and impact load-bearing performance under compression by 1.5 ± 0.25 times. In three-point bending experiments under both quasi-static and impact loading conditions, the load-carrying capacity of the double arrowhead and tetrachiral auxetic cores was found to be more than 1,86 ± 0.38 times that of the honeycomb core sandwich panels.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48259020","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}

引用次数: 7

Modelling the response regimes of elastomer-coated concrete slabs subjected to blast pressure loading 弹性体涂层混凝土板在爆炸压力荷载作用下的响应状态建模

IF 2

International Journal of Protective Structures Pub Date : 2022-03-26 DOI: 10.1177/20414196221075821

Chanel Fallon, G. McShane

{"title":"Modelling the response regimes of elastomer-coated concrete slabs subjected to blast pressure loading","authors":"Chanel Fallon, G. McShane","doi":"10.1177/20414196221075821","DOIUrl":"https://doi.org/10.1177/20414196221075821","url":null,"abstract":"Elastomer coatings have been found to offer protection to structural components when subjected to dynamic load cases, such as impact and blast. One such application of interest is the protection of concrete structures. Elastomer coatings have the potential to provide a cost effective and practical protective solution. The dynamic response of quasi-brittle concrete structures to blast loading is complex, with a range of dynamic response regimes. It remains to be identified in which regimes of response an elastomer coating can offer a protective benefit. Numerical and analytical modelling of thin, one-way reinforced concrete slabs subjected to varying intensities of simulated blast loading is carried out, in order to ascertain the protective effect of an elastomeric coating. Three configurations are considered: uncoated, coated with elastomer on the blast-receiving face and coated with elastomer on the non-blast-receiving face. It is found that the slab is relatively insensitive to the elastomer coating during response regimes where concrete damage is minimal. At higher load intensities, where the slab exhibits severe damage, the numerical results indicate a substantial reduction in slab deflections may be achieved by coating on the non-blast-receiving face. At the highest loading intensities, a shift in failure mechanism is observed to one dominated by transverse shear at the supports. An analytical model quantitatively predicts a substantial coating benefit in protecting against this failure mechanism.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41425103","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}

引用次数: 1

Recent advances in auxetics: Applications in cementitious composites 膨润土的最新进展：在水泥基复合材料中的应用

IF 2

International Journal of Protective Structures Pub Date : 2022-03-18 DOI: 10.1177/20414196211062620

Zihong Gan, Y. Zhuge, D. Thambiratnam, Tommy H. T. Chan, T. Zahra, Mohammad Asad

{"title":"Recent advances in auxetics: Applications in cementitious composites","authors":"Zihong Gan, Y. Zhuge, D. Thambiratnam, Tommy H. T. Chan, T. Zahra, Mohammad Asad","doi":"10.1177/20414196211062620","DOIUrl":"https://doi.org/10.1177/20414196211062620","url":null,"abstract":"Auxetic materials, possessing negative Poisson’s ratios (NPRs), have the ability to shrink (or expand) in the lateral direction under an axial compressive (or tensile) force respectively. Due to this unique feature, an auxetic material is found to sustain high energy absorption capacity, fracture toughness and shear resistance and thus regarded as one of the future materials in the field of impact protection. However, civil engineering applications of auxetic structures or materials are minimal due to miscellaneous restrictions on NPR effects. Accumulative developments in auxetics have facilitated their applications in cementitious materials in recent years. This paper presents an overview of recent advances in the development of auxetic cementitious composites and analyses and summarises their mechanical properties under different loading conditions. Prior to extensive finite element simulations, more attention has been given to the limited experimental results. Particular attention is paid to the expansionary feasibility of the parent material to introduce auxetic behaviour, with precise identification of the limitations, innovative composition methods and facilitation of auxetic features. Finally, the paper outlines the limitations of the current research and envisages few future research opportunities in auxetic cementitious composites.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45273779","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}

引用次数: 2

Innovative impact testing machine for enhancing impact related research in Australia 创新冲击试验机，加强澳大利亚冲击相关研究

IF 2

International Journal of Protective Structures Pub Date : 2022-03-03 DOI: 10.1177/20414196211073502

Mohammad Asad, T. Zahra, D. Thambiratnam, Tommy H. T. Chan, Xue-mei Liu, Y. Zhuge, M. Hayne, Anthony Morris, Christina Nguyen

{"title":"Innovative impact testing machine for enhancing impact related research in Australia","authors":"Mohammad Asad, T. Zahra, D. Thambiratnam, Tommy H. T. Chan, Xue-mei Liu, Y. Zhuge, M. Hayne, Anthony Morris, Christina Nguyen","doi":"10.1177/20414196211073502","DOIUrl":"https://doi.org/10.1177/20414196211073502","url":null,"abstract":"This paper summarises the development of a state-of-art impact testing machine for simulating impacts such as vehicular crashes or debris impacts onto structures. The machine has a 200 kg pneumatically powered projectile which can travel horizontally within the barrel of the machine with a maximum velocity of 50 m/s to impact the target structure. The maximum kinetic energy that can be generated by the projectile is 125 kJ by using different combinations of mass and velocity. The diameter of the projectile is 214 mm, and its impacting face can be changed to different shapes, such as flat circle, flat square or an elliptical nose to suit different impact scenarios. An innovative braking mechanism incorporating a crush tube is attached within the barrel to ensure safety when the projectile fails to be restrained by the impact. The crush tube can absorb the maximum imparted by the moving projectile. An advanced data acquisition system is installed to collect quantitative and qualitative test data during a period of 50 ms to 1 s. Two high-speed digital image correlation (DIC) cameras are attached and synchronised with the operation of the impact testing machine to record the images at the rate of 50,000 frames per second. Outputs in terms of strains, deformations, accelerations of the target structure with a record of damage history can be analysed using this 3D DIC technique. The paper also briefly presents the first application of this machine for impact testing masonry wall structures.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45038968","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}

引用次数: 1