Implementation of an empirical tool for fast prediction of bomb airblast loading

As terrorist attacks continue all over the world and, therefore, the alarming rate of countries governments as well as the awareness of people about danger is significantly increasing, in recent years high explosive airblast effects assessment and protection have become a fundamental concern for structural designers. In this article, the implementation of an original predictive tool based on the literature empirical data to develop analyses of blast loading consequent to a bomb explosion is described. The in-house developed model enables the fast calculation of the distribution of the main blast wave parameters around and over three-dimensional complex geometries virtually reproducing potential attractive targets for terrorists. Considering these capabilities, the use of the proposed novel methodology is desirable in the preparatory and retrofit design in view of evaluating blast-induced adverse consequences and, accordingly, to identify and effectively set up the most appropriate protective strategies and countermeasures.

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Vibration characteristics of triple-gear-rotor system in compressed air energy storage under variable torque load

Science Progress ◽

10.1177/0036850420987058 ◽

2021 ◽

Vol 104 (1) ◽

pp. 003685042098705

Author(s):

Xinran Wang ◽

Yangli Zhu ◽

Wen Li ◽

Dongxu Hu ◽

Xuehui Zhang ◽

...

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Element Model ◽

Rotor System ◽

Dynamic Responses ◽

System Response ◽

Rotating Speed ◽

Torque Load ◽

Set Up ◽

Two Stages

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.

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Optimum Design for the Frame of Open Type Abrasive Flow Polish Machine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.497.89 ◽

2012 ◽

Vol 497 ◽

pp. 89-93

Author(s):

Liang Liang Yuan ◽

Ke Hua Zhang ◽

Li Min

Keyword(s):

Finite Element ◽

Natural Frequency ◽

Finite Element Methods ◽

Optimization Design ◽

Low Cost ◽

Three Dimensional ◽

Force Model ◽

Optimization Analysis ◽

Open Type ◽

Set Up

In order to process heterotype hole of workpiece precisely, an open abrasive flow polish machine is designed, and the optimization design of machine frame is done for low cost. Firstly, basing on the parameters designed with traditional ways, three-dimensional force model is set up with the soft of SolidWorks. Secondly, the statics and modal analysis for machine body have been done in Finite element methods (FEM), and then the optimization analysis of machine frame has been done. At last, the model of rebuild machine frame has been built. Result shows that the deformation angle value of machine frame increased from 0.72′ to 1.001′, the natural frequency of the machine decreased from 75.549 Hz to 62.262 Hz, the weight of machine decreased by 74.178 Kg after optimization. It meets the strength, stiffness and angel stiffness requirement of machine, reduces the weight and cost of machine.

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A Transient Simulation of Heated Soil Vapor Extraction System

Volume 1 ◽

10.1115/ht-fed2004-56425 ◽

2004 ◽

Cited By ~ 1

Author(s):

T. Roy ◽

R. S. Amano ◽

J. Jatkar

Keyword(s):

Heat Source ◽

Three Dimensional ◽

Soil Vapor Extraction ◽

Extraction System ◽

Vapor Extraction ◽

Predictive Tool ◽

Heating Source ◽

Time Required ◽

Heated Soil ◽

Remediation Process

Soil remediation process by heated soil vapor extraction system has drawn considerably attention for the last few years. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. Our present study is concentrated on modeling one transient Heated Soil Vapor Extraction System and predicting the time required for effective remediation. The process developed by Advanced Remedial Technology, consists of a heating source pipe and the extraction well embedded in the soil. The number of heat source pipes and the extraction wells depends on the type of soil, the type of pollutants, moisture content of the soil and the size of the area to be cleaned. The heat source heats the soil, which is transported in the interior part of the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then driven out of the soil by the extraction well. The extraction well consists of the blower which would suck the vaporized gases out of the system. A three-dimensional meshed geometry was developed using gambit. Different boundary conditions were used for heating and suction well and for other boundaries. Concentrations of different chemicals were collected from the actual site and this data was used as an initial condition. The analysis uses the species transport and discrete phase modeling to predict the time required to clean the soil under specific conditions. This analysis could be used for predicting the changes of chemical concentrations in the soil during the remediation process. This will give us more insight to the physical phenomena and serve as a numerical predictive tool for more efficient process.

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Computer-aided design of multi-purpose steel headframes for mines with a new technical level

E3S Web of Conferences ◽

10.1051/e3sconf/202017401048 ◽

2020 ◽

Vol 174 ◽

pp. 01048

Author(s):

Elena Kassikhina ◽

Vladimir Pershin ◽

Nina Rusakova

Keyword(s):

Cross Sections ◽

Computer Aided Design ◽

Information Technologies ◽

Three Dimensional ◽

Numerical Control ◽

Technical Level ◽

Resource Saving ◽

Existing Structures ◽

Set Up ◽

Aided Design

The existing structures of the steel sinking headgear and permanent headframe do not meet the requirements of resource saving (metal consumption and manpower input at installation), and the present methods of the headframe designing do not fully reflect recent possibilities of applying of the advanced information technologies. Technical level of the modern software makes it possible for designers to set up multiple numerical experiments to create a computer simulation that allows solving the problem without field and laboratory experiments, and therefore without special costs. In this regard, a mathematical simulation has been developed and based on it, software to select cross-sections of multi- purpose steel headframe elements and to calculate proper weight of its metal structures depending on the characteristics and hoisting equipment. A headframe drawing is displayed, as the results of the software work, including list of elements, obtained optimal hoisting equipment in accordance with the initial data. The software allows speeding up graphic work and reducing manpower input on calculations and paper work. The software allows developing a three-dimensional image of the structure and its functional blocks, based on the obtained initial parameters, as well as developing control software for units with numerical control (NC) in order to manufacture multi-purpose headframes.

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Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.329.761 ◽

2007 ◽

Vol 329 ◽

pp. 761-766 ◽

Cited By ~ 1

Author(s):

Y. Zhang ◽

Masato Yoshioka ◽

Shin-Ichiro Hira

Keyword(s):

High Speed ◽

Permanent Magnets ◽

Three Dimensional ◽

Video Camera ◽

High Speed Video ◽

High Speed Video Camera ◽

The Media ◽

Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

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Exploring Nature's plasticity with a flexible probing tool, and finding new ways for its electronic distribution

Biochemical Society Transactions ◽

10.1042/bst0300078 ◽

2002 ◽

Vol 30 (2) ◽

pp. 78-82 ◽

Cited By ~ 3

Author(s):

M. Beier ◽

M. Baum ◽

H. Rebscher ◽

R. Mauritz ◽

A. Wixmerten ◽

...

Keyword(s):

Three Dimensional ◽

In Situ Synthesis ◽

Light Modulation ◽

Genomic Assays ◽

Electronic Distribution ◽

Spatial Light Modulation ◽

Microarray Fabrication ◽

Set Up ◽

Microarray Format

Concepts and results are described for the use of a single, but extremely flexible, probing tool to address a wide variety of genomic questions. This is achieved by transforming genomic questions into a software file that is used as the design scheme for potentially any genomic assay in a microarray format. Microarray fabrication takes place in three-dimensional microchannel reaction carriers by in situ synthesis based on spatial light modulation. This set-up allows for maximum flexibility in design and realization of genomic assays. Flexibility is achieved at the molecular, genomic and assay levels. We have applied this technology to expression profiling and genotyping experiments.

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Assessing biases, relaxing moralism: On ground-truthing practices in machine learning design and application

Big Data & Society ◽

10.1177/20539517211013569 ◽

2021 ◽

Vol 8 (1) ◽

pp. 205395172110135

Author(s):

Florian Jaton

Keyword(s):

Machine Learning ◽

William James ◽

A Priori ◽

Learning Algorithms ◽

Three Dimensional ◽

Ground Truth ◽

Machine Learning Algorithms ◽

Ground Truthing ◽

Set Up ◽

The Moment

This theoretical paper considers the morality of machine learning algorithms and systems in the light of the biases that ground their correctness. It begins by presenting biases not as a priori negative entities but as contingent external referents—often gathered in benchmarked repositories called ground-truth datasets—that define what needs to be learned and allow for performance measures. I then argue that ground-truth datasets and their concomitant practices—that fundamentally involve establishing biases to enable learning procedures—can be described by their respective morality, here defined as the more or less accounted experience of hesitation when faced with what pragmatist philosopher William James called “genuine options”—that is, choices to be made in the heat of the moment that engage different possible futures. I then stress three constitutive dimensions of this pragmatist morality, as far as ground-truthing practices are concerned: (I) the definition of the problem to be solved (problematization), (II) the identification of the data to be collected and set up (databasing), and (III) the qualification of the targets to be learned (labeling). I finally suggest that this three-dimensional conceptual space can be used to map machine learning algorithmic projects in terms of the morality of their respective and constitutive ground-truthing practices. Such techno-moral graphs may, in turn, serve as equipment for greater governance of machine learning algorithms and systems.

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Preliminary results of numerical simulation of submarine landslide-generated waves

10.5194/egusphere-egu21-284 ◽

2021 ◽

Author(s):

Ramtin Sabeti ◽

Mohammad Heidarzadeh

Keyword(s):

Numerical Simulation ◽

Numerical Modelling ◽

Numerical Solutions ◽

Numerical Technique ◽

Source Region ◽

Three Dimensional ◽

Terminal Velocity ◽

Sensitivity Analyses ◽

Physical Experiments ◽

Set Up

Landslide-generated waves have been major threats to coastal areas and have led to destruction and casualties. Their importance is undisputed, most recently demonstrated by the 2018 Anak Krakatau tsunami, causing several hundred fatalities. The accurate prediction of the maximum initial amplitude of landslide waves (&#951;max) around the source region is a vital hazard indicator for coastal impact assessment. Laboratory experiments, analytical solutions and numerical modelling are three major methods to investigate the (&#951;max). However, the numerical modelling approach provides a more flexible and cost- and time-efficient tool. This research presents a numerical simulation of tsunamis due to rigid landslides with consideration of submerged conditions. In particular, this simulation focuses on studying the effect of landslide parameters on &#951;max. Results of simulations are compared with our conducted physical experiments at the Brunel University London (UK) to validate the numerical model.We employ the fully three-dimensional computational fluid dynamics package, FLOW-3D Hydro for modelling the landslide-generated waves. This software benefit from the Volume of Fluid Method (VOF) as the numerical technique for tracking and locating the free surface. The geometry of the simulation is set up according to the wave tank of physical experiments (i.e. 0.26 m wide, 0.50 m deep and 4.0 m). In order to calibrate the simulation model based on the laboratory measurements, the friction coefficient between solid block and incline is changed to 0.41; likewise, the terminal velocity of the landslide is set to 0.87 m/s. Good agreement between the numerical solutions and the experimental results is found. Sensitivity analyses of landslide parameters (e.g. slide volume, water depth, etc.) on &#951;max are performed. Dimensionless parameters are employed to study the sensitivity of the initial landslide waves to various landslide parameters.

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