Impact and close-in blast response of auxetic honeycomb-cored sandwich panels: Experimental tests and numerical simulations

Qi, Chang,Remennikov, Alex,Pei, Lian-Zheng,Yang, Shu,Yu, Zhi-Hang,Ngo, Tuan D. Elsevier 2017 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.180 No.-

<P><B>Abstract</B></P> <P>Protecting building, critical infrastructure and military vehicles from Improvised Explosive Devices (IEDs) has become a critical task. This study aims to examine the performance of a new protective system utilizing auxetic honeycomb-cored sandwich panels for mitigation of shock loads from close-in and contact detonations of high explosives. Both field blast tests and drop weight tests were performed using the proposed sandwiches asa shield for concrete panels in combination with conventional steel protective plates. The combined shield was found to be effective in protecting reinforced concrete structures against severe impact and close-in blast loadings. The honeycomb core with re-entrant hexagonal cells shows evident auxetic characteristics which contribute substantially to outstanding force mitigation and blast-resistance performances of such sandwich panels. Numerical simulations showed good agreement with the experimental results. The proposed auxetic panels were found to perform better than conventional honeycomb panels of the same size, areal density and material. Both were found to boost the energy absorption of the monolithic steel plate by a factor of 2.5 by changing its deformation pattern under close-in blast loading. In addition, a combination of the steel plate and an auxetic sandwich panel has aerial specific energy absorption (<I>ASEA</I>) higher than either of them, showing great potential for the development of lightweight blast protection of civil, mining, military, nuclear infrastructure and vehicles.</P>

The Optimization of Control Parameters: Finite-time and Fixed-time Synchronization of Inertial Memristive Neural Networks with Proportional Delays and Switching Jumps Mismatch

Qi Chang,Yongqing Yang,Li Li,Fei Wang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

This thesis’s object is inertial memristive neural networks (IMNNs) with proportional delays and switching jumps mismatch. Different from the traditional bounded delay, the proportional delay will be infinite as t → ∞. The finite-time synchronization (FN-TS) and fixed-time synchronization (FX-TS) can be realized with the devised controllers for the drive-response systems (D-RSs). Along with the Lyapunov function and some inequalities, the synchronization criteria of D-RSs are given. This paper presents an optimization model with minimum control energy and dynamic error as objective functions, aiming to obtain more accurate and optimized controller parameters. An intelligent algorithm: particle swarm optimization with stochastic inertia weight (SIWPSO) algorithm is introduced to solve the optimization model. Meanwhile, an integrated algorithm for selecting optimal control parameters is presented as well. In this method, the optimal control parameters and the setting time of synchronization can be obtained directly. At last, some simulations are presented to verify the theorems and the optimization model.

Improvement of Knee Flexion and Extension Simulation Accuracy in KneeRobo

Qichang Qi,Yoshie Maeda,Kazunori Yamazaki,Noritaka Sato,Yoshifumi Morita,Hiroyuki Ukai,Kouji Sanaka 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

In a previous paper, we reported on the initial development of KneeRobo, which replicates knee joint troubles experienced by patients in order to enable students studying to become physical or occupational therapists to gain practical training/testing virtually. We also developed a control algorithm that enabled KneeRobo to realize involuntary internal/external rotation during knee flexion and extension. However, it is well known that in addition to internal/external rotation, abduction/adduction also occurs involuntarily during knee flexion and extension. Consequently, this paper proposes a new control method that improves the simulation accuracy of KneeRobo’s knee joint movements. This is accomplished by developing a control algorithm and designing a pulley arrangement that facilitates realization of involuntary movements such as internal/external rotation and abduction/adduction during knee flexion and extension by KneeRobo. The results of experimental comparison with the actual knee joint movements of a healthy person confirm that the knee joint movements simulated by the improved KneeRobo are accurate.

Reliability analysis of nuclear safety-class DCS based on T-S fuzzy fault tree and Bayesian network

Zhang Xu,Deng Zhiguang,Jian Yifan,Huang Qichang,Peng Hao,Ma Quan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5

The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved

Conceptual design of a MW heat pipe reactor

Wu Yunqin,Zheng Youqi,Chen Qichang,Li Jinming,Du Xianan,Wang Yongping,Tao Yushan 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.3

In recent years, unmanned underwater vehicles (UUV) have been vigorously developed, and with the continuous deepening of marine exploration, traditional energy can no longer meet the energy supply. Nuclear energy can achieve a huge and sustainable energy supply. The heat pipe reactor has no flow system and related auxiliary systems, and the supporting mechanical moving parts are greatly reduced, the noise is relatively small, and the system is simpler and more reliable. It is more favorable for the control of unmanned systems. The use of heat pipe reactors in unmanned underwater vehicles can meet the needs for highly compact, long-life, unmanned, highly reliable, ultra-quiet power supplies. In this paper, a heat pipe reactor scheme named UPR-S that can be applied to unmanned underwater vehicles is designed. The reactor core can provide 1 MW of thermal power, and it can operate at full power for 5 years. UPR-S has negative reactive feedback, it has inherent safety. The temperature and stress of the reactor are within the limits of the material, and the core safety can still be guaranteed when the two heat pipes are failed.

Effective leaching and extraction of valuable metals from electrode material of spent lithium-ion batteries using mixed organic acids leachant

Yuanpeng Fu,Yaqun He,Hangchao Chen,Cuiling Ye,Qichang Lu,Rongnian Li,Weining Xie,Jie Wang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.79 No.-

The present work focuses on simultaneous recycling of Li and Co from crushed products of mixedelectrode materials using mixed organic acids, in which benzenesulfonic acid and formic acid werecooperatively used as the leaching reagents. Results show that the optimal leaching efficiency of 97% Coand 99% Li were obtained under the conditions of 1.3 mol/L benzenesulfonic acid, 1.5 mol/L formic acid, asolid to liquid (S/L) ratio of 30 g/L, and 40 min reaction time at 50 C. Meanwhile, the leaching of Li and Cofits well to logarithmic rate model with apparent activation energy of 32.7 and 47.0 kJ/mol in this givenleaching system, respectively. Besides, cobalt was directly recovered from the leach liquor as pure cobaltbenzene sulfonic with the recovery efficiency of 99%, and lithium can be entirely precipitated by addingphosphoric acid. Further, the reaction mechanism involves the leaching-hydrating-complexing model ofLiCoO2 particles was proposed based on the dissolution behavior of metals and then verified bymorphological and phase characterization (i.e. FT-IR, XRD and SEM-EDS) of the recycling product. Thewhole process is found to be effective and sustainable for recovery of Li, Co and graphite from mixedindustrial crushing product of spent LIBs.

Hospitalization Due to Asthma Exacerbation: A China Asthma Research Network (CARN) Retrospective Study in 29 Provinces Across Mainland China

Jiangtao Lin,Bin Xing,Huaping Tang,Lan Yang,Yadong Yuan,Yuhai Gu,Ping Chen,Xiaoju Liu,Jie Zhang,Huiguo Liu,Changzheng Wang,Wei Zhou,Dejun Sun,Yiqiang Chen,Zhuochang Chen,Mao Huang,Qichang Lin,Chengpin 대한천식알레르기학회 2020 Allergy, Asthma & Immunology Research Vol.12 No.3

Purpose: Details of patients hospitalized for asthma exacerbation in mainland China are lacking. To improve disease control and reduce economic burden, a large sample survey among this patient population is indispensable. This study aimed to investigate the clinical characteristics and outcomes of such patients. Methods: A retrospective study was conducted on patients hospitalized for asthma exacerbation in 29 hospitals of 29 regions in mainland China during the period 2013 to 2014. Demographic features, pre-admission conditions, exacerbation details, and outcomes were summarized. Risk factors for exacerbation severity were analyzed. Results: There were 3,240 asthmatic patients included in this study (57.7% females, 42.3% males). Only 28.0% used daily controller medications; 1,287 (39.7%) patients were not currently on inhaled corticosteroids. Acute upper airway infection was the most common trigger of exacerbation (42.3%). Patients with severe to life-threatening exacerbation tended to have a longer disease course, a smoking history, and had comorbidities such as hypertension, chronic obstructive pulmonary disease (COPD), and food allergy. The multivariate analysis showed that smoking history, comorbidities of hypertension, COPD, and food allergy were independent risk factors for more severe exacerbation. The number of patients hospitalized for asthma exacerbation varied with seasons, peaking in March and September. Eight patients died during the study period (mortality 0.25%). Conclusions: Despite enhanced education on asthma self-management in China during recent years, few patients were using daily controller medications before the onset of their exacerbation, indicating that more educational efforts and considerations are needed. The findings of this study may improve our understanding of hospital admission for asthma exacerbation in mainland China and provide evidence for decision-making.