International Journal of Protective Structures最新文献_第6页

Shock qualification of low-cost blast resistant wheels by in field tests 通过现场试验对低成本防爆车轮进行冲击鉴定

IF 2

International Journal of Protective Structures Pub Date : 2022-12-01 DOI: 10.1177/20414196221075823

P. Silvestri, G. Naselli, E. Cepolina, M. Zoppi

{"title":"Shock qualification of low-cost blast resistant wheels by in field tests","authors":"P. Silvestri, G. Naselli, E. Cepolina, M. Zoppi","doi":"10.1177/20414196221075823","DOIUrl":"https://doi.org/10.1177/20414196221075823","url":null,"abstract":"This paper presents the results obtained during an experimental campaign on blast resistant wheels designed for a low-cost demining machine, derived from an agricultural tractor. Such wheels must fulfil two requirements: first, they have to be able to retain their mechanical integrity in case of blast and still work after one or more explosions, in order to be able to drive the machine out of the minefield without human intervention; second, they must reduce as much as possible the amount of energy transferred to the vehicle, to protect the on-board equipment from the effect of the detonation of a landmine. One of the goals of the experimental activity was to compare two wheels characterized by different designs. Mechanical performance and capacity of the wheels to reduce the energy transferred to the vehicle have been assessed to verify whether the wheels were suitable for the task and to identify which wheel performs best. Physical integrity of both wheels was assessed by visual inspection after each explosion. To evaluate the energy transferred to the vehicle, a measurement of the potential energy transferred, by means of a ballistic pendulum, equipped with an encoder, was performed together with a triaxial acceleration measurement in correspondence of the wheel hub. The triaxial accelerometer measurement was then also used to assess the behaviour of the wheels mounted on the vehicle after tests on the ballistic pendulum. Wheel performances have been quantified using specific features and frequency domain functions, related to the damage induced by the vibration at the interface between the hub and the demining machine. The obtained results suggest that the heaviest wheel performs better both in terms of mechanical integrity and of shock response.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66136401","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

Mechanical behavior of different fiber lengths mix-proportions carbon fiber reinforced concrete subjected to static, impact, and blast loading 不同纤维长度配合比碳纤维增强混凝土在静态、冲击和爆炸荷载作用下的力学性能

IF 2

International Journal of Protective Structures Pub Date : 2022-11-10 DOI: 10.1177/20414196221138596

Yeou-Fong Li, G. Ramanathan, Jin-Yuan Syu, Chih-Hong Huang, Ying-Kuan Tsai

{"title":"Mechanical behavior of different fiber lengths mix-proportions carbon fiber reinforced concrete subjected to static, impact, and blast loading","authors":"Yeou-Fong Li, G. Ramanathan, Jin-Yuan Syu, Chih-Hong Huang, Ying-Kuan Tsai","doi":"10.1177/20414196221138596","DOIUrl":"https://doi.org/10.1177/20414196221138596","url":null,"abstract":"Impact and blast wave loadings act as high instant energy and might cause damage to reinforced concrete infrastructures. This research aims to investigate the effect of using different length proportions of carbon fiber on the mechanical behaviors of concrete. Moreover, in this study, original carbon fiber and sizing-removed carbon fiber were added into concrete with different mix-proportions. The sizing on the carbon fiber surface was removed by using heat-treated method. In addition, the carbon fiber was dispersed by a high-pressure air compressor. Lengths of 12 mm and 24 mm carbon fibers were used in different mix-proportions to find the highest mechanical strength of carbon fiber reinforced concrete (CFRC) under a 1% fiber-to-cement weight ratio. Compressive, flexural, and impact tests were conducted on CFRC specimens. The CFRC specimen with 50% 12 mm and 50% 24 mm sizing-removed carbon fiber attained the highest impact resistance, and it also had the best performance under blast wave loading compared with the other CFRC specimens. The broken CFRC specimens were examined by an optical microscope to identify the failure mode of the carbon fibers in CFRC specimens. The addition of 50% 12 mm and 50% 24 mm sizing-removed carbon fiber can significantly improve the compressive and flexural strength of reinforced concrete.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42215960","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

Shock wave propagation in a double room model 双人间模型中的冲击波传播

IF 2

International Journal of Protective Structures Pub Date : 2022-11-01 DOI: 10.1177/20414196221137918

G. Ruscade, I. Sochet, K. Djafer

引用次数: 0

Study on dynamic response and safety control of reinforced concrete rigid frame structure under foundation pit blasting 钢筋混凝土刚架结构在基坑爆破作用下的动力响应及安全控制研究

IF 2

International Journal of Protective Structures Pub Date : 2022-10-26 DOI: 10.1177/20414196221136159

Shuoyan Zhang, Chuan-bo Zhou

{"title":"Study on dynamic response and safety control of reinforced concrete rigid frame structure under foundation pit blasting","authors":"Shuoyan Zhang, Chuan-bo Zhou","doi":"10.1177/20414196221136159","DOIUrl":"https://doi.org/10.1177/20414196221136159","url":null,"abstract":"Subway station is usually located in the dense area of urban buildings (structures). The blasting construction of subway station foundation pit is bound to have adverse effects on adjacent buildings (structures). Therefore, it is necessary to study the dynamic response of the building (structure) and propose the safety threshold of vibration velocity. Based on the foundation pit blasting project of Hejialong Station of Wuhan Rail Transit Line 12, the vibration monitoring of the field blasting test is carried out. Combined with LS-DYNA numerical simulation software, the dynamic response characteristics of a reinforced concrete rigid frame natatorium near the foundation pit are studied, and safety thresholds for structural vibration velocities are derived. It is worth noting that the structure is a large span reinforced concrete rigid frame structure, which is different from the general reinforced concrete frame structure. The safe allowable vibration velocity in the specification is not fully applicable to the structure. Therefore, it is necessary to focus on the dynamic response of the structure under the blasting effect and propose the safety threshold of structural vibration velocity, which can provide reference for the subsequent foundation blasting. The results are as follows: Blasting seismic waves in different propagation media, their energy attenuation is different. By analyzing the vibration velocity of reinforced concrete rigid frame structures, it is found that the high-level amplification effect occurred at specific height range. In addition, the vibration velocity changes abruptly at the parts where the shape and dimensions of the rigid frame cross-section change. The peak vibration velocity and the maximum principal stress of the concrete elements were statistically analyzed to obtain the linear relationship equation, and the vibration velocity safety control threshold of the structure was predicted to be V = 5.089 cm/s.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49504535","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

Safety assessment of concrete pipeline considering the effect of pipe diameter subjected to blasting vibration 考虑爆破振动影响的混凝土管道安全评价

IF 2

International Journal of Protective Structures Pub Date : 2022-09-30 DOI: 10.1177/20414196221116650

Huazhang Cao, N. Jiang, Yingkang Yao, Jinshan Sun, Yiwen Huang

引用次数: 1

Blast wave interaction with structures – An overview 冲击波与结构的相互作用——概述

IF 2

International Journal of Protective Structures Pub Date : 2022-09-26 DOI: 10.1177/20414196221118595

Obed Samuelraj Isaac, Omar Ghareeb Alshammari, E. Pickering, S. Clarke, S. Rigby

{"title":"Blast wave interaction with structures – An overview","authors":"Obed Samuelraj Isaac, Omar Ghareeb Alshammari, E. Pickering, S. Clarke, S. Rigby","doi":"10.1177/20414196221118595","DOIUrl":"https://doi.org/10.1177/20414196221118595","url":null,"abstract":"Blast–obstacle interaction is a complex, multi-faceted problem. Whilst engineering-level tools exist for predicting blast parameters (e.g. peak pressure, impulse and loading duration) in geometrically simple settings, a blast wave is fundamentally altered upon interaction with an object in its path, and hence, the loading parameters are themselves affected. This article presents a comprehensive review of key research in this area. The review is formed of five main parts, each describing: the direct loading of a blast wave on the surface of a finite-sized structure; the modified pressure of the blast wave in the wake region of three main obstacle types – blast walls, obstacles, wall/obstacle hybrids; and finally, a brief description of some methods for predicting loading parameters in such blast–obstacle interaction settings. Key findings relate to the mechanisms governing blast attenuation, for example, diffraction, reflection (diverting away from the target structure), expansion/volume increase, vortex creation/growth, as well as obstacle properties influencing these, such as porosity (blockage ratio), obstacle shape, number of obstacles/rows, arrangement and surface roughness.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45712670","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: 5

Experimental verification of different analytical approaches for estimating underwater explosives 水下爆炸物不同分析方法的实验验证

IF 2

International Journal of Protective Structures Pub Date : 2022-09-25 DOI: 10.1177/20414196221120511

P. R. Nowak, T. Gajewski, P. Peksa, P. Sielicki

{"title":"Experimental verification of different analytical approaches for estimating underwater explosives","authors":"P. R. Nowak, T. Gajewski, P. Peksa, P. Sielicki","doi":"10.1177/20414196221120511","DOIUrl":"https://doi.org/10.1177/20414196221120511","url":null,"abstract":"The clearance of underwater ordnance is one of the most complex tasks entrusted to appropriately trained and equipped soldiers. State-of-the-art knowledge in this area is rarely published and is most often possessed by a narrow group of navy specialists. The aim of this paper was to find a link between the existing mathematical models for the peak pressure of underwater explosion with measurements of small charge detonations for long ranges to the observation point in real life scenarios. We have shown the results of the research in which the underwater explosion tests were presented for different TNT equivalents and standoff distances and thus distance ratios. The curves of pressure versus time of ignition were reported. The measurements were confronted with empirical formulas. The comparison showed large, but expected, differences, since the empirical formulas are advised for smaller distance ratios. Based on the conclusions from the study, the new methodology to identify the loading from underwater explosions based on a database collected was postulated. By creating a survey methodology for ships crew for recording explosion parameters, a large number of events can be registered without a strict setup of the test area. The database obtained can be used by military commanders to identify the explosive hazard in the Baltic Sea region.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41409735","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: 4

An experimentally validated numerical analysis of UHP-FRC subjected to blast loading UHP-FRC在爆炸载荷作用下的实验验证数值分析

IF 2

International Journal of Protective Structures Pub Date : 2022-09-07 DOI: 10.1177/20414196221120512

M. Sherif, H. Othman, H. Marzouk, H. Aoude

{"title":"An experimentally validated numerical analysis of UHP-FRC subjected to blast loading","authors":"M. Sherif, H. Othman, H. Marzouk, H. Aoude","doi":"10.1177/20414196221120512","DOIUrl":"https://doi.org/10.1177/20414196221120512","url":null,"abstract":"This paper presents a new material constitutive model for simulating the uniaxial material behavior of ultra-high performance fiber reinforced concrete (UHP-FRC). The model accounts for the contribution of the steel fiber content to the tensile behavior. The model variables are the fracture energy, the characteristic length, and the crack bandwidth. Thus, it guarantees a mesh size independent numerical modeling of UHP-FRC. The model is developed based on the reported results of a state-of-the-art and highly accurate experimental investigation for the uniaxial behavior of UHP-FRC. This paper also adopts the concrete damage plasticity model (CDP) as a multi-axial yield surface criterion and presents the applicability of the material constitutive model and CDP for modeling UHP-FRC under unconfined non-contact blast loading. The results of the numerical models are validated against the experimental data of shock tube testing conducted by the authors at the University of Ottawa shock tube in collaboration with Ryerson University. The results revealed that the developed material constitutive model accurately represented the uniaxial behavior of UHP-FRC. The CDP model combined with the material constitutive model developed in this study can accurately model UHP-FRC structures under unconfined non-contact blast loading.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43851831","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

Mitigation of blast loading through blast–obstacle interaction 通过爆障相互作用减轻爆炸载荷

IF 2

International Journal of Protective Structures Pub Date : 2022-09-02 DOI: 10.1177/20414196221115869

Omar Ghareeb Alshammari, Obed Samuelraj Isaac, S. Clarke, S. Rigby

{"title":"Mitigation of blast loading through blast–obstacle interaction","authors":"Omar Ghareeb Alshammari, Obed Samuelraj Isaac, S. Clarke, S. Rigby","doi":"10.1177/20414196221115869","DOIUrl":"https://doi.org/10.1177/20414196221115869","url":null,"abstract":"Obstructing the passage of blast waves is an effective method of mitigating blast pressures downstream of the obstacle. To this end, the interaction between a blast wave and a simplified structural shape, such as a cylinder, has been widely investigated to understand the complex flow pattern that ensues around the obstacle. The patterns include the interference zones of the incident wave, the diffracted wave, and other secondary waves in the downstream region. Such zones are responsible for causing significant modifications to the blast wave parameters. This research aims to identify and study the factors that serve to mitigate the resulting blast loads downstream of a cylindrical obstacle – both on the ground, and on a rigid wall target that the obstacle is aiming to protect. Inputs from this numerical study are also used to develop a fast-running predictive method based on an artificial neural network (ANN) model. It was found that the size of the cylinder, the strength of the blast wave, the position of the cylindrical obstruction, and the target length, all have remarkable effects on the development of the complex flow-field downstream, and on the impulse mitigation on a reflective target. A number of key mitigation mechanisms are identified, namely shadowing and interference, and their origins and significance are discussed. An ANN model trained using scaled input parameters could successfully predict impulse values on such a reflective target. Using this model to predict the response of previously unseen configurations (for the ANN) gave excellent correlation, thereby demonstrating the high fidelity of this fast-running tool, and its ability to predict the effectiveness of various wave-cylinder interactions in mitigating blast loading.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49107608","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

A study on mechanical behavior of Kevlar fiber reinforced concrete under static and high-strain rate loading 凯夫拉纤维增强混凝土在静态和高应变率荷载下的力学性能研究

IF 2

International Journal of Protective Structures Pub Date : 2022-08-14 DOI: 10.1177/20414196221118596

Yeou-Fong Li, Yanyan Huang, Jin-Yuan Syu, Ying-Kuan Tsai, Chih-Hong Huang

{"title":"A study on mechanical behavior of Kevlar fiber reinforced concrete under static and high-strain rate loading","authors":"Yeou-Fong Li, Yanyan Huang, Jin-Yuan Syu, Ying-Kuan Tsai, Chih-Hong Huang","doi":"10.1177/20414196221118596","DOIUrl":"https://doi.org/10.1177/20414196221118596","url":null,"abstract":"Reinforced concrete structures sometimes are deteriorated and damaged by seismic and blast wave loadings, and the resistance of fiber-reinforced concrete was tested at a loading of high-strain rate. Therefore, concrete structures were needed to improve the dynamic load resistance and energy absorption capabilities. In infrastructures, fiber is incorporated into concrete and is used to strengthen structures to increase its durability and resistance to high-strain rate loadings. In this study, the quasi-static and dynamic mechanical behaviors of Kevlar fiber-reinforced concrete were studied by the compressive strength test and Split Hopkinson Pressure Bar test, respectively. The 0.5% weight ratio Kevlar fiber content of KFRC specimens attained the highest strength in the quasi-static and dynamic test compared with benchmark and other 1.0%, 1.5% weight ratios. The KFRC specimens with the length of 12 mm and 24 mm exhibit similar effects in the quasi-static compressive strengths, but the KFRC specimens with the length of 24 mm fiber attained higher strain energies under dynamic loading.","PeriodicalId":46272,"journal":{"name":"International Journal of Protective Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46130369","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