Дисертації з теми "Impact Dynamic Loads"
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Asadi, Ghasem Vaez-Zadeh. "Dynamic response of ship structures to impact loads." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29310.
Повний текст джерелаApplied Science, Faculty of
Mechanical Engineering, Department of
Graduate
Hendrix, Jessica Laine. "Dynamic analysis techniques for quantifying bridge pier response to barge impact loads." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000859.
Повний текст джерелаLi, Huawei. "Dynamic performance of reinforced concrete beams and joints subjected to impact loads." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/84205.
Повний текст джерелаSmagina, Zana. "Dynamic amplification for moving vehicle loads on buried pipes : Evaluation of field-tests." Thesis, KTH, Bro- och stålbyggnad, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-36801.
Повний текст джерелаDo, Van Tin. "Dynamic Analysis and Design of Monolithic and Segmental Concrete Bridge Columns against Impact Loads." Thesis, Curtin University, 2019. http://hdl.handle.net/20.500.11937/77166.
Повний текст джерелаClark, Brian. "The behaviour of rollover protective structures subjected to static and dynamic loading conditions." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16292/1/Brian_Clark_Thesis.pdf.
Повний текст джерелаClark, Brian. "The behaviour of rollover protective structures subjected to static and dynamic loading conditions." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16292/.
Повний текст джерелаОвчарова, Наталія Юріївна. "Скінченно-елементний аналіз швидкісного деформування захисних елементів машинобудівних конструкцій". Thesis, Інститут проблем машинобудування ім. А. М. Підгорного НАН України, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/32352.
Повний текст джерелаThe thesis for a candidate of technical science degree in speciality 05.02.09 – Dynamics and Strength of Machines (engineering sciences) – Kharkov National University "Kharkov Polytechnic Institute", Kharkiv, 2017. In the thesis, the actual scientific and technical problem of determining the dynamic stress-strain state of the protective elements of machine-building structures under impulse and shock loads solved to ensure their strength and effective use during operation. The thesis proposes an improved three-dimensional model of high-rate deformation of structural elements, which is different by taking into account elastic-plastic finite deformations and dynamic properties of materials. Based on the proposed model, the dependences of the distribution of stresses on the speed of impact on spatial and temporal coordinates in structural elements made of various materials obtained. New features of the process of high-rate deformation of elements under local loads detected, differing in the definition of the size of a restricted stress zone with large gradients, the formation of craters and the process of unloading with the appearance of residual stresses and damages. Dependencies between stresses and impact speeds in a three-layer element for individual layers and deformations in layers depending on the speed of the impactor obtained. The dynamic stress-strain state changes significantly both in space coordinates and in time. Therefore, even for thin-walled constructions, the use of the theory of plates and shells is undesirable, since in this case the law of stress distribution over the thickness is preliminarily assumed, and part of the stresses perpendicular to the middle surface are not taken into account at all. The processes of high-speed deformation occur both in the elastic and in the plastic stage and partially accompanied by rather large deformations. Therefore, the work uses three-dimensional models, even for thin-walled structures. From a mathematical point of view, such problems are essentially non-linear and require analysis of a three-dimensional dynamic stress-strain state. The problems of high-rate elastic-plastic deformation of elements of cylindrical structures are considered. It is shown, that the largest displacements and stresses develop in local zones and in the case when the speed is increase up to V ≥ 150 m/s, the area of intense displacements and stresses is R ≤ (10-12) r, where r is the radius of the zone load. These features of the dynamic stress-strain state make it possible to isolate the corresponding region of the element and to make refined calculations for it using a denser grid. A number of practical problems of analyzing the stress-strain state of the elements of the gas turbine engine corps under shock loading considered which differ in the purpose, geometric characteristics and properties of the materials. It is shown, that the largest displacements and stresses develop in bounded zones and rapidly decrease in spatial coordinates both in time and in unloading. It is shown, that when the blade fragment is detached, as well as the foreign particles fall into the flow at the working speeds of the gas turbine engine rotation, the stress intensities do not exceed the prescribed boundaries. In some cases, preference is given to two-layer structures, since they resist shock loads better, than single-layer ones with a larger thickness of the same material.
Овчарова, Наталія Юріївна. "Скінченно-елементний аналіз швидкісного деформування захисних елементів машинобудівних конструкцій". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/32351.
Повний текст джерелаThe thesis for a candidate of technical science degree in speciality 05.02.09 – Dynamics and Strength of Machines (engineering sciences) – Kharkov National University "Kharkov Polytechnic Institute", Kharkiv, 2017. In the thesis, the actual scientific and technical problem of determining the dynamic stress-strain state of the protective elements of machine-building structures under impulse and shock loads solved to ensure their strength and effective use during operation. The thesis proposes an improved three-dimensional model of high-rate deformation of structural elements, which is different by taking into account elastic-plastic finite deformations and dynamic properties of materials. Based on the proposed model, the dependences of the distribution of stresses on the speed of impact on spatial and temporal coordinates in structural elements made of various materials obtained. New features of the process of high-rate deformation of elements under local loads detected, differing in the definition of the size of a restricted stress zone with large gradients, the formation of craters and the process of unloading with the appearance of residual stresses and damages. Dependencies between stresses and impact speeds in a three-layer element for individual layers and deformations in layers depending on the speed of the impactor obtained. The dynamic stress-strain state changes significantly both in space coordinates and in time. Therefore, even for thin-walled constructions, the use of the theory of plates and shells is undesirable, since in this case the law of stress distribution over the thickness is preliminarily assumed, and part of the stresses perpendicular to the middle surface are not taken into account at all. The processes of high-speed deformation occur both in the elastic and in the plastic stage and partially accompanied by rather large deformations. Therefore, the work uses three-dimensional models, even for thin-walled structures. From a mathematical point of view, such problems are essentially non-linear and require analysis of a three-dimensional dynamic stress-strain state. The problems of high-rate elastic-plastic deformation of elements of cylindrical structures are considered. It is shown, that the largest displacements and stresses develop in local zones and in the case when the speed is increase up to V ≥ 150 m/s, the area of intense displacements and stresses is R ≤ (10-12) r, where r is the radius of the zone load. These features of the dynamic stress-strain state make it possible to isolate the corresponding region of the element and to make refined calculations for it using a denser grid. A number of practical problems of analyzing the stress-strain state of the elements of the gas turbine engine corps under shock loading considered which differ in the purpose, geometric characteristics and properties of the materials. It is shown, that the largest displacements and stresses develop in bounded zones and rapidly decrease in spatial coordinates both in time and in unloading. It is shown, that when the blade fragment is detached, as well as the foreign particles fall into the flow at the working speeds of the gas turbine engine rotation, the stress intensities do not exceed the prescribed boundaries. In some cases, preference is given to two-layer structures, since they resist shock loads better, than single-layer ones with a larger thickness of the same material.
Majstorovic, Jordan Mitchell. "Top Tether: Dynamic Loads and the Effects of Various Parameters; Effectiveness in Side Impacts." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429646981.
Повний текст джерелаGu, Gunmo. "Dynamic impact load to railway bridges induced by structural response and track irregularities." Thesis, University of Newcastle Upon Tyne, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519578.
Повний текст джерелаCripwell, Adam Michael. "The impact of load and frequency on the biomechanical, physiological and perceptual responses to dynamic pushing." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1008183.
Повний текст джерелаBarakati, Amir. "Dynamic interactions of electromagnetic and mechanical fields in electrically conductive anisotropic composites." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/3562.
Повний текст джерелаBanfi, Davide. "A field and laboratory study on the dynamic response of the Eddystone lighthouse to wave loading." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/11607.
Повний текст джерелаFelix, Isbi. "Dynamic analysis of the impact of grid connection of "La Higuera" hydropower plant to the transmission grid." Thesis, KTH, Elektriska energisystem, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-118929.
Повний текст джерелаTahmasebinia, Faham. "Numerical modelling of reinforced concrete slabs subject to impact loading." Access electronically, 2008. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080716.152001/index.html.
Повний текст джерелаChapman, Ruth. "Modelling the influence of viral load on transmission of HIV and the impact of therapy in the dynamics of transmission." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498189.
Повний текст джерелаNjagarah, Hatson John Boscoh. "Modelling the role of amelioration and drug lords on drug epidemics and the impact of substance abuse on the dynamics of HIV/AIDS." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17935.
Повний текст джерелаENGLISH ABSTRACT: Substance abuse is an imminent danger on the health of both substance users and nonusers. In general, abuse of psychoactive substances is associated with high risk behaviour, mortality and morbidity. The drug use cycle involves inextricably intertwined variants such as production, trading and usage of both licit and illicit addictive substances. The dynamics of substance use involve initiation, addiction, rehabilitation/treatment and quitting/ recovery. In response to supply and abuse of monster drugs, control strategies such as law enforcement and rehabilitation have been stepped up to reduce access to drugs by targeting drug kingpins and harm reduction respectively. In this thesis, we model the factors affecting the prevalence of substance abuse, the effect of drug lords on the prevalence of substance abuse, and the impact of substance abuse on the prevalence of HIV/AIDS. We formulate mathematical models based on systems of autonomous differential equations describing the dynamics of the sub- populations involved in the drug using cycle. We examine the effects of amelioration, rehabilitation/treatment and re- initiation on the prevalence of substance abuse. Our results suggest that, recruitment into rehabilitation and amelioration in the presence of quitting for light users reduce the prevalence of substance abuse; re-initiation and amelioration without quitting for light users increase the prevalence of substance abuse. Our assessment of the impact of drug lords and the effect of law enforcement on drug epidemics shows that, the presence of drug lords seriously constraints the efforts to reduce substance abuse since they increase access to drugs. However, law enforcement if stepped up in response to the population of drug lords, greatly reduces the prevalence of substance abuse. Given the associated influence of drugs on high risky behaviour, as a cofactor for sexually transmitted infections, we assess the influence of substance abuse on the prevalence of Human Immunodeficiency Virus (HIV). Our results show that dissemination of information regarding HIV and drug use reduces HIV prevalence whereas, there is faster spread of the epidemic and high prevalence with increased sexual contact.
AFRIKAANSE OPSOMMING: Dwelmmisbruik is ’n dreigende gevaar vir die gesondheid van beide dwelm gebruikers en nie-gebruikers. In die algemeen, word die misbruik van psigoaktiewe dwelms verbind met hoë risiko gedrag, mortaliteit en morbiditeit. Die dwelmgebruikskringloop behels onlosmaaklik vervlegde variante soos vervaardiging, handel en gebruik van beide wettige en onwettige verslawende middels. Die dinamika van dwelms behels aanvang, verslawing, rehabilitasie/ behandeling en staking/herstel. In reaksie op die misbruik en verskaffing van monster dwelms, is beheer strategieë soos wetstoepassing en rehabilitasie verskerp, om die toegang tot dwelms te verminder, deur onderskeidelik te fokus op dwelmspilfigure en skadebeperking. Die belangrikste doel van hierdie verhandeling is om die faktore te modelleer wat die voorkoms van dwelmmisbruik beïnvloed, die uitwerking van dwelmbase op die voorkoms van dwelmmisbruik, en die trefkrag van dwelmmisbruik op die voorkoms van MIV / VIGS. Ons formuleer wiskundige modelle gegrond op stelsels van outonome differensiaalvergelykings, wat die dinamika beskryf van die sub-bevolkinge wat in die dwelmgebruikskringloop betrokke is. Ons ondersoek die effekte van verbetering, rehabilitasie/behandeling en heraanvang op die voorkoms van dwelmmisbruik. Ons resultate dui dat, werwing tot rehabilitasie en verbetering in die teenwoordigheid van stakende tydelike verbruikers, die voorkoms van dwelmmisbruik verminder; heraanvang en verbetering sonder dat tydelike verbruikers staak, verhoog die voorkoms van dwelmmisbruik. Ons raming van die invloed van dwelmbase en die uitwerking van wetstoepassing op dwelm-epidemies toon dat, die teenwoordigheid van dwelmbase belemmer grotendeels die pogings om dwelmmisbruik te verminder, aangesien hulle toegang tot dwelms verhoog. Nietemin, as die wetstoepassing verskerp word in reaksie op die dwelmbaasbevolking, word die voorkoms van dwelmmisbruik aansienlik verminder. Gegewe die gepaardgaande invloed van dwelms op hoë risiko gedrag as ’n kofaktor vir seksueel oordraagbare infeksies, beraam ons die invloed van dwelmmisbruik op die voorkoms van die Menslike Immunogebreksvirus (MIV). Ons resultate toon dat inligtingverspreiding rakende MIV en dwelmgebruik, MIV-voorkoms verlaag, terwyl daar ’n vinniger verspreiding van die epidemie en hoë voorkoms is, met verhoogde seksuele kontak.
Queiroz, Janiel Silva de. "AnÃlise transiente paramÃtrica de sistema poste-defensa devido ao choque de veÃculos." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9509.
Повний текст джерелаIt is known that is inevitable the incidence of traffic accidents in highways, where hundreds of thousands of vehicles pass daily. These accidents can cause material damages, physical and moral injuries to involved persons, besides fatalities. When collisions are into an electric distribution pole, these are responsible by five thousand residences without electric power immediately. In this case, the stop in supplying can take four hours to residents who live close to accident site due to replacement work, as well as to generating high costs to replace the poles. So, it is necessary to study a system that protects the pole, as well as safeguards the vehicles drivers in case of collision. The objective of this work is to evaluate the behavior of pole and of system pole-defence due to the vehicles shock. Two parametric analyses are carried out. The first one is the numerical modal analysis in order to determine the influence of components like cables and defence in the pole natural parameters. The second one is the transient parametric analysis of pole and of pole-defence system. In this case, the vehicle mass and his impact time are varied. These analyses are executed in the commercial program based on the Finite Elements Method, SAP2000 V.14.0. The displacement history of pole free end is compared between the several models, as well as with the results obtained when the dynamic load maximum value is applied statically. From results it is noticed that defence carries out his paper reducing the possibility of collapse due to increasing the natural frequencies and making away from excitation frequencies of impact loads. From transient analysis it is concluded that defence raises the rigidity of the system by reducing the displacements.
Bian, Jian. "Ultimate flexural limit states analysis of prestressed concrete sleeper." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/63660/1/Jian_Bian_Thesis.pdf.
Повний текст джерелаPapenmeier, Svenja [Verfasser]. "Properties and dynamics of suspended load and near-bed fine cohesive sediments in highly impacted estuaries. Case studies from the Weser, Ems and Elbe estuaries (Germany) / Svenja Papenmeier." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1029457085/34.
Повний текст джерелаNicoletti, Vanni. "Experimental Evaluation of Infill Masonry Walls Stiffness for the Modelling of Non-Structural Components in R.C. Frame Buildings." Doctoral thesis, Università Politecnica delle Marche, 2018. http://hdl.handle.net/11566/253124.
Повний текст джерелаInfill walls are commonly disregarded in the modelling of reinforced concrete (r.c.) frame structures and only their contribution in terms of mass is taken into account assuming that resistance and stiffness do not affect the structural response. This practice is supported by the fact that (i) at ultimate limit state infill walls are usually considered to be completely damaged, so that their contribution is negligible in terms of stiffness, while (ii) at the damage limitation limit state the value of the interstorey drift, obtained by neglecting the infill walls stiffness contribution, is commonly considered to be conservative. However, for strategic buildings, such as schools, hospitals, police and fire stations, it is crucial to preserve the infill walls from any damage, even for severe earthquake, in order to guarantee the building occupancy during the emergency management. Furthermore, these buildings are sometimes seismically protected with system and devices (dampers, isolators, etc…) whose design requires the real dynamic behaviour of the structure (in terms of frequencies and/or displacements and/or velocities) to be considered. To this purpose, it becomes crucial to accurately model the entire structure, including infill walls, and to validate this model on the basis of experimental evidences. The wall typology and the construction procedures are source of uncertainties in modelling interactions between structural and non-structural components. Thus, an experimental evaluation of the stiffness properties of the wall infill panel could be very useful to assess the stiffening contribution added by the infill masonry walls to the concrete frame in the structural model adopted for the design. In this thesis is presented a procedure for developing accurate global finite element (f.e.) models of infilled r.c. frame buildings based on results of experimental an operational modal analysis of non-structural components and of the whole buildings. In particular, impact load tests with an instrumented hammer are performed on homogeneous wall panels to identify the modal parameters (frequency and mode shapes) and to estimate the mechanical properties of the masonry walls. Afterwards, the infill walls are included in the f.e. structural model, whose modal parameters are compared with those derived with operational modal analysis based on ambient vibration measurements. Furthermore, an experimental campaign on three specimens of infill masonry walls built in the Laboratory of Materials and Structures of the Faculty of Engineering at the Università Politecnica delle Marche is conducted. These specimens are built with the target to reproduce the features of some of the in situ investigated infill walls and are tested both dynamically and statically. First of all, impact load tests with an instrumented hammer are performed to investigate the out of plane dynamic behaviour of these walls; then, lateral load tests are carried out to investigate the in plane static behaviour of the panel under low level of lateral forces. The experimental results obtained are used to calibrate f.e. models of the specimens with the aim to evaluate the reliability of the masonry mechanical properties estimated through different approaches.
Nilsson, Lucas. "Estimation of Ship Properties for Energy Efficient Automation." Thesis, Linköpings universitet, Reglerteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133557.
Повний текст джерелаGenom att inkludera matematiska modeller som beskriver ett systems dynamik i styrningsalgoritmer, kan man åstadkomma en automatisk styrning med förbättrad effektivitet, robusthet och noggrannhet. Med dessa modeller går det att förutsäga beteendet hos systemet och därmed öppnas också möjligheten att använda sig av detta i styrningen. Problemet är att om dessa modeller inte beskriver systemets dynamik tillräckligt bra kan prestandan istället sänkas genom dessa metoder. Den här sortens problem kan man lösa genom att aktivt skatta systemets dynamik under körning, med hjälp av metoder för systemidentifiering, signalbehandling och sensorfusion. I denna exjobbsrapport har möjligheterna att skatta ett skepps girdynamik undersökts. Den matematiska modell som beskriver skeppets dynamik är en grålådemodell som baserar sig på fysikaliska och mekaniska samband. Denna modells egenskaper beskrivs därför av fysikaliska storheter så som massa, tröghetsmoment och tyngdpunkt, vilka alla är okända. Detta innebär att vid modellskattning skattas dessa fysikaliska storheter, vilka kan vara av stort intresse. En simuleringsmiljö med en skeppsmodell med fyra frihetsgrader har skapats och använts för att validera metoder för systemidentifiering. En modell av ett roterbart framdrivningssystem har också härletts och inkluderats i simuleringsmodellen. Vid systemidentifiering och skattning av skeppets egenskaper har dels inverkan av mätbrus analyserats samt även möjligheter till att detektera skillnader i dynamik. Detta har gjorts med Monte Carlo-simuleringar av skattningsmetoden med olika brusrealiseringar för att analysera hur mätbrus påverkar variansen och metodfelet hos skattningarna. Resultaten visar att vissa parametrar skattas med större noggrannhet och hos dessa kan därmed en förändring i dynamik identifieras när endast tio minuter av data har använts. En metod baserad på kumulativ summering av residualer har formulerats och validerats, detta för att undersöka om en sådan metod kan ge snabb och effektiv detektion av systemförändringar. Resultat visar på robusthet i att detektera skillnader i dynamik efter ungefär fyra minuter av datainsamling. Slutligen har metoderna validerats på data insamlad på ett riktigt skepp för att undersöka potentialen under verkliga omständigheter. Resultaten visar att just denna data inte är lämplig för denna applikation samt några problem som kan leda till försämrade resultat.
Хворост, Василь Валерійович, Василий Валерьевич Хворост та V. V. Khvorost. "Обґрунтування параметрів прогонових будов на поверхні шахт з урахуванням переходу на полегшені огороджувальні конструкції". Thesis, Видавництво НГУ, 2012. http://ir.nmu.org.ua/handle/123456789/203.
Повний текст джерелаДиссертация на соискание ученой степени кандидата технических наук по специальности 05.15.04 «Шахтное и подземное строительство». – ГВУЗ «Национальный горный университет», Днепропетровск, 2012.
Thesis for obtaining scientific degree of candidate of technical sciences by speciality 05.15.04 – «Mining and underground construction». – State Institution of Higher Education «National Mining University», Dnipropetrovs’k, 2012.
Дисертацію присвячено розв’язанню актуального науково-технічного завдання обґрунтування параметрів прогонових будов поверхні шахт з урахуванням переходу на полегшені огороджувальні конструкції на підставі закономірностей зміни динамічних характеристик. Результати комп’ютерного моделювання методом скінченних елементів та теоретичних розрахунків дозволили проаналізувати динамічні процеси у прогонових будовах галерей і встановити закономірності порушення їх міцності. Отримані експериментальним шляхом динамічні характеристики прогонових будов використано для оцінювання міцності, стійкості та витривалості динамічно навантажених конструкцій прогонових будов. Закономірності, отримані в результаті комп’ютерного моделювання динамічних процесів галерей, використано для розробки рекомендацій з визначення ширини резонансної зони та величини коефіцієнта динамічності прогонових будов у комплексі будівель і споруд поверхні шахт гірничодобувних підприємств Криворізького басейну за умови переходу на полегшені огороджувальні конструкції.
Диссертация посвящена решению актуальной научно-технической задачи обоснования параметров пролетных строений поверхности шахт с учетом перехода на облегченные ограждающие конструкции на основе закономерностей изменения динамических характеристик. В работе выполнен системный анализ современного состояния и основных тенденций развития проектирования пролетных строений на поверхности горнодобывающих предприятий. Для моделирования напряженно-деформированного состояния пролетных строений был использован вычислительный комплекс SCAD, широко используемый в практике инженерного анализа как в Украине, так и за рубежом. Проверка аналитических методов расчета методом конечных элементов в программе SCAD для ряда математических моделей показал, что принятые допущения, используемые в моделях в аналитическом методе, не оказывают значительного влияния на характер поведения и численные значения амплитудно-частотных характеристик. Результаты компьютерного моделирования методом конечных элементов и теоретических расчетов позволили проанализировать динамические процессы в пролетных строениях галерей и установить закономерности нарушения их прочности. Выполнены экспериментальные исследования напряженно-деформированного состояния пролетных строений в комплексе зданий и сооружений поверхности шахт горнодобывающих предприятий Криворожского бассейна. Полученные экспериментальным путем динамические характеристики пролетных строений использованы для оценки прочности, устойчивости и выносливости динамично нагруженных конструкций пролетных строений. Закономерности, полученные в результате компьютерного моделирования динамических процессов, использованы для разработки рекомендаций по определению ширины резонансной зоны и величины коэффициента динамичности пролетных строений в условиях перехода на облегченные ограждающие конструкции. На основании впервые установленных закономерностей изменения амплитудно-частотных характеристик пролетных строений от различного характера внешних нагрузок и геометрических параметров ограждающих конструкций решена актуальная научная задача установления закономерностей изменения жесткости и частот собственных колебаний галерей при условии перехода на облегченные ограждающие конструкции. Сопоставление теоретических и экспериментальных результатов производилось на основании сравнения частот колебаний, максимальных перемещений. Установленное удовлетворительное соответствие этих факторов является достаточным для вывода о достоверности математической модели. Внедрение эффективных ограждающих конструкций пролетных строений на основе использования разработанных рекомендаций по определению рациональной массы пролетного строения позволяет получить экономический эффект на одной транспортерной галереи 299 тыс. грн.
Thesis is devoted to the urgent scientific and technical problem explanation analysis of span structures on the mines surface characteristics with account of transition to eased cladding structures on the basis of dynamic characteristic principles. Computer simulations results by finite elements and theoretical calculation methods allowed analyzing the dynamic processes in span structures galleries and establishing principles of its strength defection. Experimentally obtained dynamic processes in span structures are used for strength, resistibility, endurance evaluation of dynamically loaded span structures. Obtained results based on the results of dynamic processes in galleries structures are used for recommendation formulation to determine the resonance zone width and dynamic index value of span structures under conditions of transition to eased cladding structures. Implementation of effective cladding structures of span structures allows reducing the cost of span structures reconstruction an average of 10…20 %.
ZHOU, XIAO-WEI. "Contribution au comportement dynamique des materiaux metalliques : etude experimentale de l'alliage al-li en torsion et en compression, simulation numerique du processus de penetration a grande vitesse." Nantes, 1988. http://www.theses.fr/1988NANT2014.
Повний текст джерелаHwang, Yann-Hour, and 黃彥豪. "Study on Dynamic Characteristics of an Airbag for Reducing Impact Loads on Structures." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/30162412782121875000.
Повний текст джерела國立臺灣海洋大學
系統工程暨造船學系
93
The airbag has been widely used as a cushioning device in the automobile industry. In this study an approach is proposed to design an airbag in isolating the impact load by varying outlet area of the exiting gas. The physical model for analyzing the airbag’s system is proposed. The governing equations of the impact load on airbag and airbag isolating system are derived by using the conservation of mass, the momentum equation and the energy equation. Results of numerical simulation of the governing equations of the airbag system show that an airbag behaves like a spring mass system as the gas outlet area becomes smaller. As the gas outlet area increases, the behavior of the mass spring system is rapidly diminished. Results of numerical simulation show that the influence of the gas outlet area is the most parameter of the airbag system. If the time rate of change of the outlet area is designed properly, the airbag can be used to decelerate an impact load within a desired time and way of motion. The most significant contribution of the present study is that a method for controlling the outlet area of an airbag for efficiently reducing the impact load to a small terminal velocity is obtained.
Hrynyk, Trevor. "Behaviour and Modelling of Reinforced Concrete Slabs and Shells Under Static and Dynamic Loads." Thesis, 2013. http://hdl.handle.net/1807/35851.
Повний текст джерелаRanadive, Gauri Satishchandra. "Methodologies for Assessment of Impact Dynamic Responses." Thesis, 2014. http://etd.iisc.ac.in/handle/2005/2794.
Повний текст джерелаRanadive, Gauri Satishchandra. "Methodologies for Assessment of Impact Dynamic Responses." Thesis, 2014. http://etd.iisc.ernet.in/handle/2005/2794.
Повний текст джерелаSrinivas, Gunti Ranga. "Applications of Advanced CAE Methodologies to Orthopaedic Implant and Vehicle Occupant cum Pedestrian Safety Countermeasure Design." Thesis, 2017. http://etd.iisc.ac.in/handle/2005/4270.
Повний текст джерела林威呈. "Investigation of Impact Load on Bridge Girders Using Dynamic Vehicle Loading." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/29794523578033601699.
Повний текст джерела逢甲大學
土木工程學系
102
Transportation construction is a crucial indicator of the economic development of a country. Excellent transportation system planning enhances the convenience of transportation and substantially benefits national economy. All processes involving material logistics, supplying resources, and product delivery rely on a comprehensive transportation system. Therefore, bridge construction is essential in transportation construction projects, and bridge designs are the crucial basis of bridge constructions. In this study, we examined the impact load of various factors on bridge girders and investigated five factors, namely the structural system of bridges (simply supported single-span beams and two-span continuous beams), span distance, wheelbase between the central and rear wheels of a standard HS20-44 truck, truck speed, and damping ratio. Subsequently, finite element analysis software (SAP2000) was adopted to establish a series of bridge girder models. Finally, the impact coefficients obtained in this study were used to investigate the impact load of dynamic vehicles on bridge girders. The results indicated that the impact coefficients were proportional to span distance and the wheelbase and speed of the truck. Furthermore, the models developed in this study conformed to the impact coefficient regulations stipulated in the bridge design specification for highways.
Merz, Nadja Christina. "The impact of foreign currency debt on credit risk; analyzing exchange rate risk in international credit markets." Master's thesis, 2017. http://hdl.handle.net/10362/26190.
Повний текст джерелаMahembe, Edmore. "Development aid and its impact on poverty reduction in developing countries : a dynamic panel data approach." Thesis, 2019. http://hdl.handle.net/10500/26490.
Повний текст джерелаEconomics
D. Phil. (Economics)
Subramanya, S. "Prediction of Physical Behavior of Rotating Blades under Tip-Rub Impact using Numerical Modeling." Thesis, 2013. http://etd.iisc.ac.in/handle/2005/3083.
Повний текст джерелаSubramanya, S. "Prediction of Physical Behavior of Rotating Blades under Tip-Rub Impact using Numerical Modeling." Thesis, 2013. http://hdl.handle.net/2005/3083.
Повний текст джерела