Engineering Commons^™

Modeling, Simulation, And Validation Of Process-Structure-Property Relationships In Fused Filament Fabrication, Aaron Grant

Electronic Theses and Dissertations

As additive manufacturing (AM) grows in popularity, the need for better simulation tools to predict the process-structure-property relationships of AM parts becomes ever more necessary to employ the technology in design of functional parts with varying degrees of complexity and performance requirements. Many simulation tools and techniques have been developed that aim to achieve this goal, and the main purpose of this research is to explore how well different simulation tools and modeling approaches can capture various AM-specific features such as inter-raster and end-of raster voids, and residual stresses induced by dissimilar rates of thermal expansion. Process simulation of fused …

Research On Simulation Platform For Equipment System Analysis, Yuping Li, Shaojie Mao, Zhenqi Ju, Zhou Fang, Guoqiang Yan

Journal of System Simulation

Abstract: With the development of equipment construction from platform-centric to network-centric, simulation analysis of equipment system is an important means and tool to support the transformation and development of equipment construction under the condition of multi-task joint operation. Starting from the requirement of system simulation analysis, a cloud-based equipment system simulation architecture is proposed to realize flexible and configurable simulation environment according to task requirements; and a high-performance simulation framework is conducted, which provides strong support for different application modes, such as parallel hyper-real-time and distributed simulation deduction. The unified description, organization and management method of model and data resources …

Research On Simulation Optimization Of Disk-Based Storage Operation Mode In Warehouse, Danlan Xie, Liu Meng, Haihong Yu, Chen Jing, Yubo Zhou, Kazi Mohiuddin

Journal of System Simulation

Abstract: As the efficiency of operation affects the overall competitiveness of the port, it is very necessary to design the storage operation mode reasonably. A disk-based storage operation mode is proposed. And the simulation model is established by using the logistics simulation software FlexSim based on the operational requirements of the warehouse. Through a large number of simulation experiments, comparing the primary storage mode with the disk-based storage mode, the results of the increase in total idle rate and the more balanced distribution of each hour utilization ratio of the forklifts are obtained. The result verifies the feasibility and effectiveness …

Pshev Cold Start Emission Simulation Based On Electric Heated Catalyst Pre-Heating, Deng Tao, Haoyuan Yu, Zhifei Li, Haixin Tan

Journal of System Simulation

Abstract: In order to reduce the emissions of the plug-in series hybrid electric vehicle (PSHEV) during the cold start phase, a vehicle model on PSHEV is established and a dynamic model of electrically heated catalyst system (EHCS) based on optimization and control strategy of engine start-stop is built. The PSHEV energy management control strategy based on EHCS preheating is proposed. The influence of different pre-heating power on EHCS temperature is simulated. By comparing SOC value of the control strategy with the original control strategy; and comparative analysis of cold start emissions of three elements catalyst under three strategies of pre-heating, …

The Simulation Assessment Of Availability For K/N Redundancy System Considering Failure Relevance Of Components, Haidong Du, Junhai Cao, Fusheng Liu, Xu Dan

Journal of System Simulation

Abstract: For the limitations existing in the system availability assessment based on the failure independent hypothesis,the availability assessment model for k/N system based on Copula function theory is built.A reliability evaluation method of fault-related system on the foundation of Agent technique is proposed. The completion of the simulation model from component entity to equipment entity resolves the question of reliability assessment existing in k/N system considering the effects of components relevance. And last, the evaluation results of system availability under different spare parts schemes are given under different material support program, the research results show that the relevance existing …

Control Optimization Of Hybrid System With Hybrid Power Based On Dp Algorithm, Deng Tao, Haoyuan Yu, Bin Xu

Journal of System Simulation

Abstract: Aiming at the complexity and diversity of energy management for HEV(hybrid electric vehicle) with hybrid power, taking the State of Charge of power battery and ultracapacitor as state variable, the torque distribution ratio between engine and motor, and the power distribution ratio between power battery and ultracapacitor as control variables, the fuel economy and emission performance as objective function, the Dynamic Programming (DP) control strategy for HEV with hybrid power is proposed. The working rules of the engine, motor, battery and ultracapacitor, are extracted from the results, and the rules of engine and motor and the fuzzy control …

Research On Hwil Simulation Of Rf/Ir Dual-Mode Sensors Based On Compact Antenna, Gao Yang, Ma Jing, Huiyang Qu, Qun Wei, Jindong Fei

Journal of System Simulation

Abstract: The advent of RF/IR dual-mode sensor technology in the more and more completed detecting environment has led to the requirement of simulation tools that are necessary to test dual-mode sensor. The hardware-in-the-loop simulation experiment and test of the radio frequency/infrared composite sensor are carried out.A RF/IR dual-mode simulation method based on the Compact antenna test ranges is proposed here. This system consists of IR simulator, RF simulator, beam-combiner etc. The testing result shows that RF/IR dual-mode simulation system has abilities of IR transmission and RF reflection, and could be used in RF/IR dual-mode sensor simulation.

Simulation And Analysis Of Supplying Station Line Selection And Impact With Real Information, Qiguang Lü, Maozeng Xu, Zhou Xiang

Journal of System Simulation

Abstract: The choice of routes and target stations of energy supply vehicles may lead to the demand cluster at the station and then induce traffic congestion, so it's necessary to analyze the effect of different choices of route and station. Based on the traffic real information, a multi-objective integer programming model is proposed in this paper, in which energy consumption and travel time of energy constrained vehicle is the optimization objective, and a two-stage genetic algorithm which aims to find optimal the route and station is designed. The simulation results based on the emPlant show that the optimal route …

Some Problems And Countermeasures In Simulation Credibility Evaluation, Jiao Peng, Zhang Qi, Xiangyu Wei, Yabing Zha

Journal of System Simulation

Abstract: With the increasing application of simulation technology in various fields, users have put forward higher requirements for the credibility of the simulation system. This paper focuses on some key issues of the credibility evaluation of the simulation system, such as the unclear expected application, the incomplete evaluation, the unclear evaluation criteria, and the open loop of evaluation conclusions. From the perspectives of comprehensive implementation of credibility assessment, strengthening the design of acceptability standards, and focusing on the evaluation of closed-loop implementation, how to solve the real problem has been studied and discussed. The research results of this paper …

Study On Ecological Compensation Of Three Gorges Basin Based On Evolutionary Game Theory, Guangming Yang, Yanjun Shi

Journal of System Simulation

Abstract: Under the background of the green development of the Yangtze River Economic Belt, based on the evolutionary game theory, the game model of the upstream and downstream governments of the Three Gorges Basin and the central ecological compensation behavior are constructed to analyze the interests appeal and compensation behaviors among the three parties, so as to have a complex interest game relationship in the Yangtze River and analyze the cases of ecological compensation in the Three Gorges Basin. The research shows that without the restriction of central government, it is difficult for the upstream and downstream governments in the …

Simulation Research On Pedestrian Evacuation Path Selection In The Metro Station, Sun Di, Zhou Jin, Xueying Gao, Ting Jiao, Lixian Zhao

Journal of System Simulation

Abstract: As the underground environment is multilayered, more confined space underground, there are many services and facilities, so that when people evacuate the subway, they will have a variety of features and choices. Path probability selection of underground pedestrian evacuation is discussed. In the first stage, models are used to plan several routes. In the second stage, according to the data of real time passenger flow of the railway station, the density of passenger flow is taken as a variable to obtain the time of pedestrian evacuation through different facilities. The traffic capacity of every passage and facility …

The Trolley Problem In Virtual Reality, Jungsu Pak, Ariane Guirguis, Nicholas Mirchandani, Scott Cummings, Uri Maoz

Student Scholar Symposium Abstracts and Posters

Would people react to the Trolley problem differently based on the medium? Immersive Virtual Reality Driving Simulator was used to examine participants respond to the trolley problem in a realistic and controlled simulated environment.

Gearbox Baffle Optimization, Megan Arduin

Masters Theses

Current literature reveals there is limited consensus on the placement of baffles within a gearbox to reduce churning losses. Thus, there is a need for a process to identify baffle clearances that result in maximum and minimum churning losses. There are two types of baffles: axial and radial. While both axial and radial baffles cause reductions in churning losses to various degrees, the focus is on the effect of radial baffles. The effect of a board (rectangular plate) baffle location on the churning losses of a single gear gearbox are evaluated using computational fluid dynamics (CFD) implemented in Ansys. Several …

Simulation And Optimization Of A Multi-Agent System On Physical Internet Enabled Interconnected Urban Logistics., Long Zheng

Electronic Theses and Dissertations

An urban logistics system is composed of multiple agents, e.g., shippers, carriers, and distribution centers, etc., and multi-modal networks. The structure of Physical Internet (PI) transportation network is different from current logistics practices, and simulation can effectively model a series of PI-approach scenarios. In addition to the baseline model, three more scenarios are enacted based on different characteristics: shared trucks, shared hubs, and shared flows with other less-than-truckload shipments passing through the urban area. Five performance measures, i.e., truck distance per container, mean truck time per container, lead time, CO₂ emissions, and transport mean fill rate, are included in …

Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Landing an unmanned aerial vehicle (UAV) on a moving platform is a challenging task that often requires exact models of the UAV dynamics, platform characteristics, and environmental conditions. In this thesis, we present and investigate three different machine learning approaches with varying levels of domain knowledge: dynamics randomization, universal policy with system identification, and reinforcement learning with no parameter variation. We first train the policies in simulation, then perform experiments both in simulation, making variations of the system dynamics with wind and friction coefficient, then perform experiments in a real robot system with wind variation. We initially expected that providing …

No-Collision Curling Trajectory Simulation System, Tian Yu, Xu Ming

Journal of System Simulation

Abstract: In just a few decades, China’s curling accomplished splendid work. But it’s scientific research falling behind a lot. Applying computer simulation technology in sports training can effectively help the athletes to understand the problems that exist in the training. When curling stone slides on the ice, it can be regarded as two-dimensional motion of rigid body, which can be decomposed into two parts: translation of the center of mass and rotation of a fixed axis around the center of mass. Using computer simulation technology to simulate the curling trajectory, and with the help of this system, the athletes can …

Modeling And Simulation Of Missile Trajectory Based On Practical Sampling, Wu Shuai, Xiaohua Zhou, Lili Wang, Xingzhong Yao

Journal of System Simulation

Abstract: Aiming at the problem of lacking the proper simulation method for missile trajectory in combat simulation training, this paper analyzes the limitations of the 6D and 3D simulation models, proposes a method of trajectory simulation with missile kinematics model and history measured data, and taking an air-to-surface ballistic missile with midcourse-terminal guidance as an example, describes the model construction process in detail. Through the verification, validation and simulation experiments, it shows that this method can simulate various types of missile trajectory with high confidence on both sides of “red and blue”, which has an important reference meaning for missile …

Overview Of Digital Twins Application And Safe Development, Li Xin, Liu Xiu, Xinxin Wan

Journal of System Simulation

Abstract: The Digital Twins simulate the whole process of the manufacture, and promote the development of smart manufacturing and other fields. In view of the rapid development and application of Digital Twins, the concept and history of Digital Twins are outlined, and its related technology system is given. The main application and development trend of Digital Twins in intelligent manufacturing as while as the main characters of Digital Twins in smart cities are combed. The cyber security problem of Digital Twins is discussed for intelligent manufacturing and smart cities. The scheme and suggestion are given for ensuring the cyber security …

Application Of Constraint Force Equation Methodology In Aircraft Stage Separation Dynamics Simulation, Yongji Wang, Bangbang Li, Liu Lei

Journal of System Simulation

Abstract: The separation process of two-stage aircraft can be divided into three periods: lock-up period, constraint period and detachment period. The guide pins have constraint on two stages, which permit only translation in X-axis direction. To avoid the complex force analysis, the guide pins can be regarded as a joint of one degree of freedom. By adding the constraint and freedom equations to traditional separation dynamics equations, a dynamics model based on constraint force equation (CFE) methodology was built. The constraint force and moment can be obtained by solving constraint force equations. The constraint force equation (CFE) methodology was …

Strengthening Of Concrete Deep Beams With Extreme Discontinuities Using Near-Surface Mounted Composites, Moustafa Seifeddin Mansour

Civil and Environmental Theses

Installation of a web opening that fully interrupts the natural load path in concrete deep beams produces regions of extreme discontinuities and reduces the shear strength. This research examined the effectiveness of using near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) reinforcement to restore the shear strength of deep beams with extreme discontinuities. The strut-and-tie model (STM) procedures were utilized to develop three different strengthening solutions around the discontinuity regions. A total of eight deep beam specimens (150 x 500 x2700 mm) with a shear span-to-depth ratio of a/h = 0.8 were constructed and tested. One beam was solid. Seven beams had a …

Development Of An Autonomous Aerial Toolset For Agricultural Applications, Terrance Life

Mahurin Honors College Capstone Experience/Thesis Projects

According to the United Nations, the world population is expected to grow from its current 7 billion to 9.7 billion by the year 2050. During this time, global food demand is also expected to increase by between 59% and 98% due to the population increase, accompanied by an increasing demand for protein due to a rising standard of living throughout developing countries. [1] Meeting this increase in required food production using present agricultural practices would necessitate a similar increase in farmland; a resource which does not exist in abundance. Therefore, in order to meet growing food demands, new methods will …

Gesture Based Control Of Semi-Autonomous Vehicles, Brian Sanders

Computational Modeling & Simulation Engineering Theses & Dissertations

The objective of this investigation is to explore the use of hand gestures to control semi-autonomous vehicles, such as quadcopters, using realistic, physics based simulations. This involves identifying natural gestures to control basic functions of a vehicle, such as maneuvering and onboard equipment operation, and building simulations using the Unity game engine to investigate preferred use of those gestures. In addition to creating a realistic operating experience, human factors associated with limitations on physical hand motion and information management are also considered in the simulation development process. Testing with external participants using a recreational quadcopter simulation built in Unity was …

Experimental Design And Testing In A Pilot-Scale Rotary Kiln For The Torrefaction Of Beech Wood Under System Restrictions, Jorge López-Ordovás, Ibai Funcia-Muguerza, Katie Chong, Javier Gil, Raúl Pérez-Vega, Tony Bridgwater

Bio-Char II: Production, Characterization and Applications

The torrefaction process increases the energy density of the torrefied feedstock through the loss of volatiles and moisture. The anhydrous weight loss (AWL) measures the loss of volatiles and it is easily correlated with the net calorific value (NCV) of the torrefied product.

This work has two different parts. The first part consists of the design of the experiments and the second includes the experiments with results. The system used in CENER, where the simulation and experiments were completed, is a rotary kiln with a maximum capacity of 500 kg/h and a range of operating temperatures between 220-310°C. The innovative …

Competence Of A Spray Passive Down-Draft Evaporative Cooling (Pdec) System For Space Cooling, Daeho Kang, Richard K. Strand

Publications and Research

A spray PDEC system has been relatively less considered than other passive cooling strategies as one of the viable low-energy solutions in the cooling of buildings while having a great potential in energy savings. This study is intended to evaluate the capability of a spray PDEC system for space cooling. It comprises four simulation scenarios to see the system response and influence of indoor thermal environment when a spray PDEC system is adopted as a primary cooling system in two different climates. The simulation results show that a spray PDEC system causes a substantial variation in the indoor thermal environment …

Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson

Master's Theses

The CubeSat Astronomy Network is a proposed system of multiple CubeSat spacecraft capable of performing follow-up observations of astronomical targets of interest. The system is intended to serve as a space-borne platform that can complement existing systems utilized for astronomical research by undergraduate and high school students. Much research and development work has been performed to develop model-based system engineering methodologies and products for CubeSat missions, including the Horizon Simulation Framework. The Horizon Simulation Framework enables the development of system models using the Extended Markup Language (XML), and its simulation program can generate system simulations over model-specified timespans. System requirements …

How Will Climate Alter Efficiency Objectives? Simulated Impact Of Using Recent Versus Historic European Weather Data For The Cost-Optimal Design Of Nearly Zero Energy Buildings (Nzebs), Florida Solar Energy Center, Delia D'Agostino

FSEC Energy Research Center®

Achieving "nearly zero energy buildings" (NZEB) has been established as a vital objective over the next decade within the European Union (EU) [1,2]. Previous work has shown that a series of very cost-effective thermal efficiency measures, equipment, appliance and renewable energy choices are available across climates to reach the NZEB objective. Resulting detailed energy and economic optimization findings have been obtained and published. One area that has just begun to be explored, however, is how selection of weather files and their application against coming climate change can influence outcomes from energy optimization procedures.

Presented at: CLIMA 2019, REHVA 13th HVAC …

Evaluation Of Data Collection Operations For Real-Time Influenza Surveillance During An Emergency, Yuwen Gu

Dissertations

It is unclear how data collection operations for surveillance alter the disease portrayal that influenza reported trends attempt to provide during an emergency. This study developed a model that simulates the collection and testing of influenza specimens after an outbreak is declared in Michigan. It performed simulation based optimization to understand which operational factors affect the biases between the growth rates of original and observed influenza incidence trends, and to quantify the predictive power of the influenza incidence trends at different points of data collection. The results show that emergency driven high risk perception increases the reporting, which leads to …

A Simulation Tool For Evaluating The Environmental Impacts Of Management Scenarios For Modern Broiler Production Systems, Martin Andrew Christie

Graduate Theses and Dissertations

The purpose of this work is to provide a simulation tool that allows broiler production practitioners and researchers to simulate the effects of farm design and management practices on resource consumption and environmental impacts. This tool allows the user to design unique farms and simulates on farm processes required to raise broiler chicks to a marketable age. The use can input data such as farm location, broiler breed, flock size, ration type, barn dimensions, and climate control equipment specifications. The algorithms used to simulate broiler breed specific feed intake, broiler weight gain, and other on farm processes such as heating, …

Analysis Of The System Response Of A Spray Passive Downdraft Evaporative Cooling System, Daeho Kang, Richard K. Strand

Publications and Research

A spray Passive Downdraft Evaporative Cooling (PDEC) system achieves great savings for space cooling and improves indoor environmental quality by supplying a large amount of fresh outdoor air. As previous studies heavily focused on the energy saving capability of a spray PDEC system due to lack of methods for a detailed analysis, the influence of cool humid supply air from a spray PDEC system in a space in buildings has not been comprehensively studied. This study is intended to evaluate the competence of a spray PDEC system as a primary cooling system in typical spaces in a primary school building …

Analysis Of A Garment-Oriented Textile Recycling System Via Simulation Approach, Reyhaneh Yavari

Major Papers

The textile industry is one of the polluting industries on the planet. Public awareness has increased manufacturers responsibility and forced them to shift from linear to the circular production line to reduce the amount of environmental impact such as; energy and freshwater consumption, toxic and fertilizer usage and cutting down the use of raw material. Also, some new business strategies like fast fashion which is a recent trend in the fashion industry by offering fast changing trend and inexpensive designs accelerate the process of purchasing new clothes that end up in landfills. Recycling, remanufacturing and reusing are some practices that …