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Effects of the windshield inclination angle on head/brain injuries in car-to-pedestrian collisions using computational biomechanics models

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Transportation Safety and Environment 2024年第2期6卷 1-12页

作者： Fang Wang Mingliang Wang Lin Hu Ke Peng Jiajie Yin Danqi Wang Liangliang Shi Zhou Zhou School of Automotive and Mechanical engineering Changsha University of Science and TechnologyChangsha 410114HunanChina Hunan Province Key Laboratory of Safety Design and Reliability Technology for engineering Vehicle Changsha University of Science and TechnologyChangsha 410114HunanChina State Key Laboratory of Vehicle NVH and Safety Technology China Automotive Engineering Research Institute Co.Ltd.Chongqing 401122China division of neuronic engineering KTH Ro y al Institute of TechnologyStockholm 14152Sweden

Car-to-pedestrian collision(CPC)accidents occur frequently,and pedestrians often suffer serious head/brain *** major cause is the primary impact with the ***,we use an umerical sim ulation method to study the influence of the windshield in-clination angle of a passenger car on pedestrian head/brain injury due to CPC *** range of the windshield inclination angle was set at 24°-50°,with an interval of 2°.The results show that the windshield angle significantly affects the pedestrian kine-matics and exerts different effects on the head injury when evaluating with various head injury *** the head peak linear/rotational acceleration and acceleration-based head injury criterion(HIC)/rotational injury criterion(RIC),the predictions at the secondary impact stage have no clear relationship with the windshield angle(R^(2)=0.04,0.07,0.03 and 0.26,respectively)and their distributions are *** the primary impact,the peak linear acceleration and HIC show a weak trend of first decreasing and then increasing with the increasing of the windshield angle,and the rotational acceleration and RIC tend to remain relatively *** the cum ulative strain dama ge measure(CSDM)criterion,the predictions at the primary impact are slightly lower than those at the secondary impact,and the trend of first decreasing and then increasing with the increase in the windshield angle is observed at both impact *** the windshield inclination angle is approximately 32°-40°,the head injury severity in both impact phases is generally lower than that predicted at other windshield angles.

关键词： car-to-pedestrian collision(CPC) head/brain injury head injury criterion(HIC) windshield inclination angle computa-tional biomechanics model(CPCBM)

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New approach for particle size and shape analysis of iron-based oxygen carriers at multiple oxidation states

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Particuology 2024年第7期90卷 493-503页

作者： Victor Purnomo Marcelo Dal Belo Takehara Robin Faust Lidiya Abdisa Ejjeta Henrik Leion division of Energy and Materials Department of Chemistry and Chemical EngineeringChalmers University of TechnologyGöteborg 41258Sweden division of Energy Science Department of Engineering Sciences and MathematicsLuleåUniversity of TechnologyLuleå97187Sweden

One of the crucial issues in the chemical looping technology lies in its bed material:the oxygen *** size analysis of an oxygen carrier is important since in a fluidized bed the material can only work well within a specific size *** the favorable size ranges for oxygen carrier materials have already been reported,none of the published studies has analyzed the particle size and shape of oxygen carriers in ***,the effect of oxygen carriers'oxidation degree on such properties has not been considered *** study aimed to report the particle size and shape analysis of five iron-based oxygen carriers,one natural ore,one synthetic material,and three residue products,at different oxidation degrees using dynamic image analysis(DIA).The oxygen carriers were prepared at different mass conversion degrees in a fluidized bed batch *** size distribution,sphericity,and aspect ratio of the oxygen carrier particles were examined experimentally using a Camsizer *** results show that the DIA method was successfully able to analyze the particle size and shape of our oxygen carriers with satisfying accuracy for *** oxidation state of the investigated materials seems to only affect the particle size and shape of oxygen carriers to a minor ***,exposures to redox cycles in a fluidized bed reactor may alter the particle size and shape of most oxygen carriers.

关键词： Oxygen carrier Size and shape analysis Dynamic image analysis Oxidation state Fluidized bed Chemical looping

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Segment-wise learning control for trajectory tracking of robot manipulators under iteration-dependent periods

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Science China(Information Sciences) 2024年第3期67卷 155-166页

作者： Fan ZHANG Deyuan MENG Kaiquan CAI The Seventh Research division Beihang University School of Automation Science and Electrical engineering Beihang University School of Electronics and Information engineering Beihang University

This paper is concerned with the amplitude boundedness problem of adaptive iterative learning control(AILC) for robot manipulators operating with iteration-dependent periods. By introducing virtual memory slots for storing historical data, a practical AILC method is proposed to achieve the segmentwise learning. This method requires less memory storage for historical information of previous iterations,especially in comparison with that of the conventional AILC methods using point-wise learning *** is shown that not only the energy boundedness but also the amplitude boundedness of estimates and inputs of practical AILC can be guaranteed. Moreover, the practical AILC method can achieve the perfect tracking objective regardless of iteration-dependent periods when the robot manipulators have a persistent full learning property. In addition, a solution to the visual manipulator platform is provided and deployed based on Coppeliasim and Matlab, which helps to show the amplitude boundedness of learning results and the perfect tracking performances of the proposed practical AILC method for robot manipulators.

关键词： amplitude boundedness iteration-dependent period iterative learning control robot manipulator segment-wise virtual memory slot

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A new neural-network-based method for structural damage identification in single-layer reticulated shells

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Frontiers of Structural and Civil engineering 2024年第1期18卷 104-121页

作者： Jindong ZHANG Xiaonong GUO Shaohan ZONG Yujian ZHANG College of Civil engineering Tongji UniversityShanghai 200092China China Construction Eighth engineering division Co. Ltd.Shanghai 200135China

Single-layer reticulated shells(SLRSs)find widespread application in the roofs of crucial public structures,such as gymnasiums and exhibition *** this paper,a new neural-network-based method for structural damage identification in SLRSs is ***,a damage vector index,NDL,that is related only to the damage localization,is proposed for SLRSs,and a damage data set is constructed from NDL *** the basis of visualization of the NDL damage data set,the structural damaged region locations are identified using convolutional neural networks(CNNs).By cross-dividing the damaged region locations and using parallel CNNs for each regional location,the damaged region locations can be quickly and efficiently identified and the undamaged region locations can be ***,a damage vector index,DS,that is related to the damage location and damage degree,is proposed for *** on the damaged region identified previously,a fully connected neural network(FCNN)is constructed to identify the location and damage degree of *** effectiveness and reliability of the proposed method are verified by considering a numerical case of a spherical *** calculation results showed that the proposed method can quickly eliminate candidate locations of potential damaged region locations and precisely determine the location and damage degree of members.

关键词： single-layer reticulated shell damage identification neural network convolutional neural network cross-partitioning method

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Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho Lee Hyeon Jun Jeon Jinwoo Choi Hyun-Taek Choi Sejin Lee The Department of Mechanical engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System engineering Research division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The division of Mechanical&Automotive engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

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Modeling asymmetric fracture mechanics of Mg alloy wire in drawing process

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Journal of Magnesium and Alloys 2024年第5期12卷 2057-2069页

作者： Sunghoon Choi Jongwon Shin Joung Sik Suh Dongchoul Kim Department of Mechanical engineering Sogang University Advanced Metals division Korea Institute of Materials Science

In this study, a numerical analysis was conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5Sr-0.1Ca alloy wire during drawing. The hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior, especially in the compression region. The aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture, with a focus on the compression region. A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress states. The wire drawing process was simulated using the Generalized Incremental Stress-State dependent damage(GISSMO)Model and the Semi-Analytical Model for Polymers(SAMP) model. The damage model's prediction and the experimental results were found to be in excellent agreement, especially in determining crack initiation. Computational analysis established a safe zone diagram for die angle and reduction ratio, and experimental validation confirmed the feasibility of this approach. The proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

关键词： Mg alloy Wire drawing Finite element method Damage model Safe zone diagram

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Research on an innovative structure of an open-ribbed steel–ultra-high performance concrete composite bridg

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Frontiers of Structural and Civil engineering 2024年第5期18卷 716-730页

作者： Xudong SHAO Xuan SUN Deqiang ZOU Junhui CAO Chuanqi YANG School of Civil engineering Hunan UniversityKey Laboratory for Wind and Bridge Engineering of Hunan ProvinceChangsha 410082China China Construction Fifth engineering division Co. Ltd.Changsha 410004China

To completely solve the problem of fatigue cracking issue of orthotropic steel bridge decks(OSDs),the authors proposed a steel–ultra-high performance concrete(UHPC)lightweight composite deck(LWCD)with closed ribs in *** on the successful application of that LWCD,an adaptation incorporating an innovative composite deck structure,i.e.,the hot-rolled section steel–UHPC composite deck with open ribs(SSD)is proposed in this paper,aiming to simplify the fabrication process as well as to reduce the cost of *** on a long-span cable-stayed bridge,a design scheme is proposed and is compared with the conventional OSD ***,a finite element(FE)calculation is conducted to reflect both the global and local behavior of the SSD scheme,and it is found that the peaked stresses in the SSD components are less than the corresponding allowable values.A static test is performed for an SSD strip specimen to understand the anti-cracking behavior of the UHPC layer under negative bending *** static test results indicate that the UHPC layer exhibited a satisfactory tensile toughness,the UHPC tensile strength obtained from the test is 1.8 times the calculated stress by the FE model of the real *** addition,the fatigue stresses of typical fatigue-prone details in the SSD are calculated and evaluated,and the influences of key design parameters on the fatigue performance of the SSD are *** to the fatigue results,the peaked stress ranges for all of the 10 fatigue-prone details are within the corresponding constant amplitude fatigue *** a fatigue test is carried out for another SSD strip specimen to explore the fatigue behavior of the fillet weld between the longitudinal and transverse *** specimen failed at the fillet weld after equivalent 47.5 million cycles of loading under the design fatigue stress range,indicating that the fatigue performance of the SSD could meet the fatigue design *** calculations and experim

关键词： steel-ultra-high performance concrete composite deck open rib strip model test static and fatigue performance orthotropic steel deck

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Deep learning to develop zero-equation based turbulence model for CFD simulations of the built environment

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Building Simulation 2024年第3期17卷 399-414页

作者： Giovanni Calzolari Wei Liu division of Sustainable Buildings Department of Civil and Architectural EngineeringKTH Royal Institute of TechnologyBrinnelvägen 23Stockholm11428Sweden

This study aims to improve the accuracy and speed of predictions for thermal comfort and air quality in built environments by creating a coupled framework between computational fluid dynamics(CFD)simulations and deep learning *** coupling approach is showcased by the development of a data-driven turbulence *** new turbulence model is built using a deep learning neural network,whose mapping structure is based on a zero-equation turbulence model for built environment simulations,and is coupled with the CFD software OpenFOAM to create a hybrid *** neural network is a standard shallow multi-layer *** number of hidden layers and nodes per layer was optimized using Bayesan optimization *** framework is trained on an indoor environment case study,as well as tested on an indoor office simulation and an outdoor building array *** show that the deep learning based turbulence model is more robust and faster than traditional two-equation Reynolds average Navier-Stokes(RANS)turbulence models,while maintaining a similar level of *** model also outperforms the standard algebraic zero-equation model due to its superior ability to generalize to various flow *** some challenges,namely the mapping constraint,the limited training dataset size and the source of generation of training data,the hybrid framework demonstrates the viability of the coupling technique and serves as a starting point for future development of more reliable and advanced models.

关键词： neural networks computational fluid dynamics(CFD) turbulence model OpenFOAM

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Performance assessment of prefabricated vertical drains in mitigating soil reliquefaction subjected to repeated seismic events using shaking table experiments

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Frontiers of Structural and Civil engineering 2024年第3期18卷 411-427页

作者： Gowtham PADMANABHAN Ganesh Kumar SHANMUGAM Department of Earthquake engineering Indian Institute of Technology RoorkeeUttarakhand 247667India Geotechnical engineering division CSIR-Central Building Research Institute Academy of Scientific and Innovative Research(AcSIR)Uttarakhand 247667India

The use of prefabricated vertical drains(PVD)in liquefiable deposits is gaining attention due to enhanced ***,investigations on PVD in mitigating re-liquefaction during repeated shaking events are not *** study performed a series of shaking table experiments on untreated and PVD-treated specimens prepared with 40%and 60%relative *** sinusoidal loading was applied with an incremental peak acceleration of 0.1g,0.2g,0.3g,and 0.4g,at 5 Hz shaking frequency with 40 s *** performance of treated ground was evaluated based on the generation and dissipation of excess pore water pressure(EPWP),induced sand densification,subsidence,and cyclic stress *** addition,the strain accumulated in fresh and exhumed PVD was investigated using geotextile tensile testing apparatus aided with digital image *** evidence of pore pressure was reported up to 0.2g peak acceleration for 40%and 60%relative density *** continuous occurrence of soil densification and drainage medium restrained and delayed the generation of EPWP and expedited the dissipation *** study demonstrates PVD can mitigate re-liquefaction,without suffering from deterioration,when subjected to medium to high intense repeated shaking events.

关键词： prefabricated vertical drains drainage re-liquefaction shaking table digital image correlation

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Turbine Passage Secondary Flow Dynamics and Endwall Heat Transfer Under Different Inflow Turbulence

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Journal of Harbin Institute of Technology(New Series) 2024年第3期31卷 51-62页

作者： Arjun K S Tide P S Biju N division of Mechanical engineering School of EngineeringCochin University of Science&TechnologyKalamassery 682022India

This study presents endwall hydrodynamics and heat transfer in a linear turbine cascade at Re 5×105 at low and high intensities of *** are numerically predicted using the standard SST model and Reθ-γtransition model as well as using the high-resolution LES *** major secondary flow components,comprising the horseshoe,corner,and passage vortices are recognized and the impact on heat or mass transfer is *** complicated behavior of turbine passage secondary flow generation and establishment are impacted by the perspective of boundary layer attributes and inflow *** passage vortex concerning the latest big leading-edge vane is generated by the enlargement of the circulation developed at the first instance adjacent to the pressure side becomes powerful and mixes with other vortex systems during its migration towards the suction *** study conclusions reveal that substantial enhancements are attained on the endwall surface,for the entire spanwise blade extension on the pressure surface,and in the highly 3-D region close to the endwall on the suction *** forecasted suction surface thermal exchange depicts great conformity with the measurement values and precisely reproduces the enhanced thermal exchange owing to the development and lateral distribution of the secondary flows along the midspan of the blade passage *** impacts of the different secondary flow structures on the endwall thermal exchange are described in depth.

关键词： turbine vane heat transfer endwall turbulence secondary flow

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