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Evaluating the blast mitigation performance of hard/soft composite structures through field explosion experiment and numerical analysis

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Acta Mechanica Sinica 2022年第1期38卷 27-36页

作者： Fengyuan Yang Zhijie Li Zhuo Zhuang Zhanli Liu Applied Mechanics Laboratory Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084China

The application of hard/soft composite structure in personnel armor for blast mitigation is relatively practical and effective in realistic protection engineering,such as the shell/liner system of the ***,there is still lacking a reliable experi-mental methodology to effectively evaluate the blast mitigation performance when the structure directly contacts the protected target,which limits the development of protection *** this paper,we proposed a new method to evaluate experi-mentally and numerically the blast mitigation performance of hard/soft composite *** blast mitigation mechanism is *** hard/soft structures were composed of ultra-high molecular weight polyethylene(UHMWPE)composite and expanded polyethylene(EPE)*** field explosion experiment,a 7.0 kg trinitrotoluene(TNT)spherical charge is used to generate blast waves at a 3.8 m stand-off distance.A pressure test device is designed to support the tested structure and measure the transmitted blast pressure pulses after passing through the *** results indicate that the hard/soft structures can mitigate the blast pressure pulse into the triangular pressure pulse,through making the pulse profile flatter,reducing the pressure amplitude,and delaying the pulse arrival ***,the combination of 7 mm UHMWPE composite and 20 mm EPE foam can reduce the blast pressure amplitude by 40%.Correspondingly,the finite element simulation is also carried out to understand the blast mitigation *** numerical results indicate that the regulation for blast pressure pulses mainly complete at the hard/soft interface,which is attributed to the reflection of pressure waves at the interface and the deformation of the soft layer compressed by the hard layer possessing kinetic ***,based on these analyses,the corresponding theoretical model is proposed,and it can well explain the experimental and numerical *** study is meaningful for e

关键词： blast mitigation Composite structure Field explosion experiment Numerical simulation

Relative performance of novel blast wave mitigation system to conventional system based on mitigation percent criteria

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Defence Technology（防务技术） 2021年第3期17卷 912-922页

作者： Moustafa Esa Mostafa S.Amin Ahmed Hassan Eng.Mechanics Dept. Military Technical CollegeKobry ElkobbahCairoEgypt Civil Eng.Dept. Military Technical CollegeKobry ElkobbahCairoEgypt

Recent researches focused on developing robust blast load mitigation systems due to the threats of terrorist *** of the main embraced strategies is the structural systems that use mitigation *** are developed from a combination of structural elements and described herein as conventional *** the promising techniques is that redirect the waves propagation through hollow *** blast wave propagation through tubes provides an efficient system since it combines many blast wave phenomena,such as reflection,diffraction,and *** this research,a novel blast load mitigation system,employed as a protection fence,is developed using a technique similar to the technique of the bent tube in manipulating the *** relative performance of the novel system to the conventional system is evaluated based on mitigation percent *** of both systems are calculated through numerical *** proposed novel system proved to satisfy high performance in mitigating the generated blast waves from charges weight up to 500 kg TNT at relatively small standoff distances(5 m and 8 m).It mitigates at least 94%of the blast waves,which means that only 6%of that blast impulse is considered as the applied load on the targeted structure.

关键词： blast mitigation blast barriers Protection system mitigation percent Protection evaluation

Incidence, casualties and risk characteristics of civilian explosion blast injury in China: 2000-2017 data from the State Administration of Work Safety

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Military Medical Research 2021年第1期8卷 1-8页

作者： Xu Wang Juan Du Zhuo Zhuang Zheng-Guo Wang Jian-Xin Jiang Ce Yang State Key Laboratory of Trauma Burn and Combined InjuryResearch Institute of SurgeryDaping HospitalArmy Medical UniversityChongqing 400042China Department of Emergency the Second Affiliated Hospital of Medical College in Zhejiang UniversityHangzhou 310009China Applied Mechanics Laboratory School of AerospaceTsinghua UniversityBeijing 100084China

Background: Civilian explosion blast injury is more frequent in developing countries, including China. However, the incidence, casualties, and characteristics of such incidents in China are ***: This is a retrospective analysis of the State Administration of Work Safety database. Incidents during a period from January 1, 2000 to April 30, 2017 were included in the analysis. The explosions were classified based on the number of deaths into extraordinarily major, major, serious and ordinary type. Descriptive statistics was used to analyze the incidence and characteristics of the explosions. Correlation analysis was performed to examine the potential correlations among various ***: Data base search identified a total of 2098 explosions from 2000 to 2017, with 29,579 casualties: 15,788 deaths(53.4%), 12,637 injured(42.7%) and 1154 missing(3.9%). Majority of the explosions were serious type(65.4%). The number of deaths(39.5%) was also highest with the serious type(P=0.006). The highest incidence was observed in the fourth quarter of the year(October to December), and at 9:00–11:00 am and 4:00–6:00 pm of the day. The explosions were most frequent in coal-producing provinces(Guizhou and Shanxi Province). Coal mine gas explosions resulted majority of the deaths(9620, 60.9%). The number of explosion accidents closely correlated with economic output(regional economy and national GDP growth rate)(r=–0.372, P=0.040;r=0.629, P=0.028).Conclusions: The incidence and civilian casualties due to explosions remain unacceptable in developing China. Measures that mitigate the risk factors are of urgently required.

关键词： Explosion blast exposure blast mitigation Overpressure Trauma and injury

Investigation of Supersonic Shock Wave Loading on Thin Metallic Sheets

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Defence Technology（防务技术） 2023年第11期29卷 10-14页

作者： Khushi Ram Kartikeya Kartikeya Puneet Mahajan Naresh Bhatnagar Department of Mechanical Engineering IIT DelhiNew Delhi110016India Department of Applied Mechanics IIT DelhiDelhi110016India

Shock tube experiments were carried out to investigate dynamic behavior of Ultra-high hardness(UHH)steel and Aluminium(Al) sheets of 0.8 mm thickness at 0.55, 0.9 and 1.18 MPa peak-over *** results showed that center point deflection increases with an increase in peak-over pressure for Al sheets. However, UHH steel sheets showed negligible deformation when loaded at low peak-over pressures and showed sudden brittle failure at high peak-over pressures. Similar results were obtained by quasi-static testing, UHH steel failed abruptly while Al showed ductile behavior. Results from literature indicate that to protect structures against shock loading it is necessary that they dissipate energy via plastic deformation. The Al sheets were shown to deform plastically both in quasi-static and shock loading. Thus, hardness along with ductility is required to dissipate supersonic shock waves.

关键词： Shock tube Peak-over pressure Shock wave blast mitigation Plastic deformation

Introduction to Enhanced Protective Film Systems

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Transactions of Tianjin University 2008年第B10期14卷 491-494页

作者： LIU Chunlin DAVID Palermo LI Guoqiang SUN Jianyun CHEN Suwen K＆C Protective Technologies（KCPT） Singapore 1 59361 Colleague of Civil Engineering Tongji University Shanghai 200092 China Sherwin-Williams Company South Holland IL 60473 USA

An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting life and property from ballistic shards or fragments. They can be designed to be stand-alone in new construction and structural retrofits or used to augment structural hardening tech-niques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT′s blast engineering capacity and SW′s material engineering principles to create engineered systems for even greater in-use performance.

关键词： explosion blast mitigation catcher system protective film systems

Introduction to Enhanced Protective Film Systems

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Transactions of Tianjin University 2008年第S1期 491-494页

作者： DAVID Palermo Sherwin-Williams Company South Holland IL 60473 USA

关键词： explosion blast mitigation catcher system protective film systems