Добірка наукової літератури з теми "Automobiles Parts Design and construction Quality control"

This research mainly according to automotive modular production characteristic, proposed for tracing method module production in batches; parts relation and order information system construction of internal and external traceability system model; using the mass matrix and the batch list theory, research on the above two kinds of design theory of quality traceability scheme based on distributed management system, and establish the integrated application model and parts material network technology suppliers; tracing back combined back and realize the goal of batches of the product quality control in advance and the defects of the products. Through the research on the theory of reference to the use of the Internet of things technology, technology focus of the study lies in the application of IDEF modeling method, the integrated use of Excel's powerful data processing tools and Pareto Diagram, combined with the RFID tag technology, and achieve the goal of defective product traceability and batch tracking combined. The key technology for the RFID radio frequency technology, the IDEF method and the two dimensional code identification etc.

The durability of concrete structures in severe environments is not only related to design and materials but also to construction. Thus, much of the observed durability problems can be ascribed due to lack of proper quality control and quality assurance during concrete construction resulting in poorly achieved construction quality. Upon completion of new concrete structures, the achieved construction quality typically shows a high scatter and variability, and during operation of the structures, any weaknesses and deficiencies will soon be revealed whatever durability specifications and materials have been applied. To a certain extent, a probability approach to the durability design can accommodate the high scatter and variability. However, a numerical approach alone is insufficient for ensuring the durability; greater control and improvements in durability also require the specification of performance-based durability requirements which can be verified and controlled during concrete construction in order to achieve quality assurance. For new major concrete infrastructure, documentation of achieved construction quality and compliance to the durability specification should be essential parts of any rational approach to controlling and increasing the durability. In the present paper, a case study is presented which provides comparisons of work performed under performance and prescriptive durability specifications.

With the transformation of the trend of vehicle electrification, the overall noise level in the vehicle is gradually reduced. The problem of low-frequency noise in the vehicle, which was previously ignored, is becoming more and more prominent. To solve the vehicle low-frequency noise problem, a combination of real-vehicle tests and simulation analysis is carried out. During the test, the driver and passengers feel that there is a relatively obvious low-frequency roar noise in the car, which results from the structural radiation noise of the trunk door vibration. Therefore, to solve this problem, we design an acoustic metamaterial with lightweight and miniaturized features based on the local resonance principle of phononic crystals. Firstly, the selection of the resonant unit configuration and the design of the band gap are implemented. Then, the layout planning of the whole vehicle, the layout of the resonance unit and the design of the base frame are implemented. The actual vehicle test results show that: after attaching the designed acoustic metamaterial, the low-frequency noise sound pressure levels in the front and rear of the vehicle were reduced by 2.0 dB (A) and 2.3 dB (A), respectively, meanwhile, the interior noise sound quality was improved. The sound pressure level at the driver’s right ear in the car has an abnormal peak of around 35Hz. In addition, the driver and passengers feel that there is a relatively obvious low-frequency roar noise in the car, and through low-pass filtering of the collected signals, it is confirmed that the peak frequency is the main cause of the low-frequency roar in the car. The low-frequency steady-state noise of the car is generally considered to be the low-frequency vibration of the body panel and the radiation occurs. Through the finite element simulation analysis (Grid Participation Analysis) of the abnormal peak frequency, the results show that the low-frequency roar is caused by the low-frequency vibration of the tailgate sheet metal, and the problem peak frequency is not coupled with the acoustic cavity mode. Facing the problem of the low-frequency roar radiated into the car by the vibration of the tailgate sheet metal parts, based on the local resonance band gap theory, we developed a design to suppress the 35 Hz vibration of the tailgate sheet metal parts and meet the characteristics of lightweight and miniaturization. By attaching the acoustic metamaterial to the tailgate and performing CAE simulation of the whole vehicle, it is determined that the structure can indeed reduce the 35 Hz noise in the car and the peak value of the tailgate sheet metal vibration.

Quality Control efforts are one of the preventive efforts to anticipate quality degradation and procedural errors carried out and to find out whether Quality Control is running well or not, an integrated application monitoring is needed so that its perFormance can be analyzed. This study aims to design an inFormation system to improve the monitoring of Quality Control in the construction construction process by producing accurate and real time data that is very much needed in decision making. The research method is carried out by making an integrated application design via a smartphone consisting of three very important parts, namely the work method or standard operating procedure, Quality Control in defect management and monitoring of the global positioning system where the Building Inspector is in monitoring. Based on the results of the application design, the results obtained are in the Form of a blueprint that can be run on project supervision. This application will assist in the process of the correct method of implementation with good results in realtime.

This paper analyzes the main management problems in drug circulation quality among pharmaceutical wholesale enterprises, and provides the construction strategy for a comprehensive quality safety control system of medicine circulation from a macro perspective. Based on the characteristics and function requirements of drug circulation management, it depicts structure model of the system, which includes three parts: sub-system of production management, perception management, and the regulatory decision-making. This paper mainly illustrates the design and research idea of the sub-system of sensor network and multi sensor management to meet the demand for the drug monitoring in circulation among pharmaceutical wholesale enterprises, that is early monitoring and warning in advance, rapid response and post evaluation and summary. The research results herein can offer beneficial reference in the further development for the system.

In many parts of the world, row crops are treated with herbicides. Because of environmental concerns, crop cultivation is suggested as an excellent method of weed control. The object of this study was to design and construct a high speed inter-row cultivator. The speed of plowing has a significant effect not only on the depth of plowing but on factors which affect the quality of soil preparation such as loosening of the upper soil layer, cutting roots of the previous crops, covering and plowing in of weeds, leveling the finished surface of the field, displacement of the son layer and so on. In this study, the designed and constructed cultivator has a toolbar, unit frame, disk coulter and a flat sweep. The unit frame is attached to a tractor mounted tool bar by a suspension linkage. The suspension linkage allows the unit frame to move up and down relative to a tool bar that the cultivator unit is attached to. The numerical analysis was performed with COSMOS/M 1.71 FEM software (Structural Research and Analysis Corporation, CA).

Sheet metal part manufacture is a precursor to various upstream assembly processes, including the manufacturing of mechanical and body parts of railcars, automobiles, ships, etc., in the transport manufacturing sector. The (re)manufacturing of railcars comprises a multi-tier manufacturing supply chain, mainly supported by local small and medium enterprises (SMEs), where siloed information leads to information disintegration between supplier and manufacturer. Technology spillovers in information technology (IT) and operational technology (OT) are disrupting traditional supply chains, leading to a sustainable digital economy, driven by new innovations and business models in manufacturing. This paper presents application of industrial DevOps by merging industry 4.0 technologies for collaborative and sustainable supply chains. A blockchain-based information system (IS) and a cloud manufacturing (CM) process system were integrated, for a supply chain management (SCM) system for the railcar manufacturer. A systems thinking methodology was used to identify the multi-hierarchical system, and a domain-driven design approach (DDD) was applied to develop the event-driven microservice architecture (MSA). The result is a blockchain-based cloud manufacturing as a service (BCMaaS) SCM system for outsourcing part production for boxed sheet metal parts. In conclusion, the BCMaaS system performs part provenance, traceability, and analytics in real time for improved quality control, inventory management, and audit reliability.

Computer numerical control (CNC) cutting machines have become essential tools for designers and architects enabling rapid prototyping, model building, and production of high-quality components. Designers often cut from new materials, discarding the irregularly shaped remains. We introduce ProjecTables, a visual augmented reality system for interactive packing of model parts onto sheet materials. ProjecTables enables designers to (re)use scrap materials for computer numerical control cutting that would have been previously thrown away, at the same time supporting esthetic choices related to wood grain, avoiding surface blemishes, and other relevant material properties. We conducted evaluations of ProjecTables with design students from Aarhus School of Architecture, demonstrating that participants could quickly and easily place and orient model parts reducing material waste. Contextual interviews and ideation sessions led to a deeper understanding of current work practices and sustainability issues with computer numerical control cutting machines and identified useful features for interactive packing to reduce waste while supporting esthetic concerns for exhibition quality design projects.

This paper proposes a robot designed for automated routine or emergency disinfection in closed premises. The robot is related to the combined type robots. The robot consists of two functional parts: a universal mobile platform (lower part) and a disinfector (upper part), which, if necessary, can be freely moved by personnel on 4 wheels. In the initial position, the upper part of the disinfection robot is at the charging station. The mobile robot drives up to the disinfector, «hooks» it (puts it on itself) and moves along the planned route. The upper part of the disinfector will have its own independent intelligent system, separate from the mobile robot, which, when a person is recognized, stops liquid disinfection: in this case, the UV lamps turn through 180°, the cylindrical body closes and ventilation of the disinfected air from the enclosed space is turned on. In addition, liquid disinfection is only enabled when detecting beds, tables and chairs. With the spray nozzles located at a height of 400 mm, the disinfector can carry out a simultaneous combined treatment of rooms with equipment and furniture, including high-quality processing of the lower surfaces of tables, chairs and beds. To improve the functional characteristics of robotic disinfectors and to simplify their design, a multifunctional robotic disinfector has been proposed. It was found that the result is achieved by the fact that in a multifunctional disinfection robot containing a mobile cart with an autonomous positioning and navigation system, a disinfection platform with a disinfection liquid spraying system and UV lamps with reflectors installed on it, the disinfection platform will have its own autonomous control and power systems.

In recent years, there have been more and more studies on the use of construction and demolition waste (CDW) as subgrade filler. The physical performance indexes of a single material of floor slabs waste (FSW) are studied, which meet the requirements of subgrade specification. From the perspective of construction quality control, it is proposed that when FSW is used as subgrade filler, the compaction thickness and the maximum allowable particle size should be controlled according to different layers, and the gradation of subgrade filler is evaluated by using the nonuniformity coefficient (Cu) and curvature coefficient (Cc). The compaction test of FSW shows that the maximum dry density and optimum moisture content of different gradations do not change much. The crushing value under the freeze-thaw cycle is proposed to evaluate the frost resistance of FSW. The crushing value of FSW after water absorption and frost heaving changes a little. The CBR and resilience modulus tests were carried out on the FSW such that the results show that they have a good relationship and the relevant expressions under different compaction degrees are fitted. When performing on-site compaction testing, it is proposed that the upper roadbed adopts the sand replacement method according to the different layers of the FSW subgrade and the settlement discrepancy method should be adopted for other parts. Through laboratory tests and construction field detective, the quality control requirements, road performance indexes, and design indexes of FSW materials are put forward.

Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná
Este trabalho tem como objetivo desenvolver uma abordagem para auxiliar as montadoras na obtenção de informações sobre os problemas e falhas que ocorrem nos veículos durante o seu uso pelos motoristas, relacionando os dados obtidos com a leitura da telemetria do veículo, assim como as percepções do motorista sobre uma determinada falha. A exploração de técnicas que auxiliam o diagnóstico automotivo é um problema a ser discutido na engenharia. As técnicas de diagnóstico devem fornecer suporte à grande gama de sistemas que surgirão nos próximos anos. Assim, é possível também utilizar a conectividade que os celulares e veículo dispõem na atualidade, com o intuito de evoluir o produto oferecido e melhorar a experiência do cliente enquanto dirige. A inclusão do cliente no processo de diagnóstico, visa permitir que os projetistas identifiquem pontos que podem ser melhorados no carro, mesmo que não apresentem erro aparente. A opinião do cliente pode ser considerada, uma vez que ele é incluído no processo como um novo “sensor" (o mais inteligente e importante de todos) capaz de reportar suas percepções. Considerando este fato, a motivação deste trabalho se encontra em: (i) Procurar alternativas para aplicar de maneira eficiente a conectividade dos veículos no processo de diagnóstico; (ii)Permitir que as montadoras possam obter informações mais concretas dos veículos que comercializam. O objeto é fornecer um sistema de interface entre o usuário e o carro auxiliando a realização dos diagnósticos preventivos mais completos do que apenas usando a telemetria. Neste projeto busca-se que haja uma interação maior com o motorista, e que a experiência das montadoras possa entrar no processo de diagnóstico. Mesmo que o cliente não tenha tanta intimidade com o funcionamento do veículo, o sistema deve orientar o motorista no processo. A entrada de dados do cliente é realizada por texto ou comando de voz. Para a análise desta entrada de dados do cliente foi realizado um estudo de mineração de dados em bases que a montadora já possuía. Estas bases são entrevistas telefônicas nas quais a montadora pergunta ao cliente problemas percebidos no carro, e então as respostas são transcritas para a base. O estudo de mineração de dados foi realizado para a criação do classificador que é responsável por receber os dados de entrada do cliente e classifica-lo em um determinado problema ligado à multimídia ou relacionado ao motor do veículo. O software contido no celular será responsável por solicitar ao sistema de sensores do veículo as leituras necessárias para que o cliente obtenha as informações que deseja. Foi realizado um experimento no qual analistas de diagnóstico responderam a um questionário que buscava analisar se o sistema proposto realmente influenciava no processo de diagnóstico, fazendo com que a solução dos problemas no veículo seja realizada em menos etapas, se comparado com o processo atual. Os resultados mostraram que a abordagem diminuiu o número de etapas necessárias para a obtenção do diagnóstico correto. Dos três estudos de caso realizados, as etapas necessárias para se chegar ao diagnóstico apropriado diminuiu em uma etapa para o primeiro estudo de caso, diminuiu uma etapa para o segundo estudo de caso, e três etapas a menos para o terceiro estudo de caso. Com estes resultados foi possível demonstrar que a abordagem proposta influiu no processo de diagnóstico aplicado atualmente pelas montadoras e concessionárias analisadas.
The goal of this project is to develop an approach to assist automakers in obtaining information about the problems and failures that occur in the vehicles during their use by drivers, relating the data obtained by reading the telemetry of the vehicle, as well as the perceptions of the driver about a particular failure. The exploration of techniques to optimize automotive diagnosis is a problem to be discussed in Engineering. Diagnostic techniques should support the wide range of systems that will emerge in the coming years. Thus, it is also possible to use the connectivity that mobile phones and vehicles have today, in order to evolve the product offered and improve the customer experience while driving. The customer inclusion in the diagnostic process aims to allow engineers identifies points to be improved in the car, even if they dont present an apparent error. The customer opinion should be considered, since he/she is included in the process as a new "sensor"(the most intelligent and important of all) able to report his/her perceptions. Considering this fact, the motivation of this research is: (i) search for alternatives to efficiently apply vehicle connectivity in the diagnostic process, (ii) enable automakers to obtain more concrete information on the vehicles they sell. The object is provide an interface between the user and the car helping them to perform a more complete preventive diagnoses than only using telemetry. In this project it is sought that there is a greater interaction with the driver, and the experience of the automakers could be included the diagnostic process. Even if the customer isnt so accustomed with the operation of the vehicle, the system must guide the driver by the process. The customer input data is performed by text or voice command. The analysis of this customer input data, a data mining study was performed based on a base that automaker already had. These bases are telephone interviews in which the automaker asks the customer for perceived problems in the car, and then the answers are transcribed to the base. The data mining study was performed to create one classifier which was responsible for receiving the input data from the customer and sorting it into a particular problem related with the multimídia or related to the motor of the vehicle. The software contained in the mobile phone will be responsible asking to the vehicle sensor system for the readings necessary for the customer can to obtain the information he/she wants. An experiment was carried out in which diagnostic analysts answered a questionnaire that sought to analyze whether the proposed system actually influenced the diagnostic process, so the solution of the problems in the vehicle was performed on less steps compared to the current process. The results showed the approach reduced the number of steps required to obtain the correct diagnosis. Of the three case studies performed, the steps required to arrive at appropriate diagnosis decreased in one step to the first case study, one step to the second case study decreased, and three less steps to the third case study . With these results it was possible to demonstrate that the proposed approach influenced the diagnostic process currently applied by the automakers and concessionaires analyzed.

Submitted in fulfilment of the requirements for the degree of Master of Technology in Business Administration: Entrepreneurial Studies & Management, Durban University of Technology, Durban, South Africa, 2017.
The automotive industry is the third largest sector in the South African economy and it plays such an important role in the economy, that it is often viewed used as a barometer of the health of the economy. Despite the relatively large number of automotive component manufacturers (ACMs) in South Africa, manufacturing a wide range of automotive components, and the incentives offered by the government to increase the local content of vehicles manufactured in the country, the majority of vehicle manufacturers as well as after-market wholesalers and retailers in South Africa source a greater proportion of their automotive components from foreign suppliers. This may be due to a number of reasons, and in this regard, this study investigated the nature and extent to which ACMs in Gauteng, South Africa, used innovative strategies to remain competitive. A quantitative research design was used, and a self-administered questionnaire was sent to all of the ACMs located in Gauteng. Some of the main findings from the study was that only 48.9% of the respondents had a Research and Development (R&D) department; ACMs ranked their clients, who include motor vehicle manufacturers and original equipment manufacturers, as the most important source of innovation, with existing employees being ranked second, suppliers ranked third, and competitors ranked fourth. The importance of a highly skilled workforce was highlighted by the finding that almost three quarters of the respondents agreed with the statement that new ideas and suggestions from employees had been implemented. Although the local motor vehicle manufacturers purchase most of the automotive components from ACMs located outside South Africa, the finding that 82% of the ACMs surveyed have been in operation for more than 10 years, with 72% of these organisations in operation for more than 15 years, indicates that most local ACMs are financially profitable and have adapted to global competition.
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Compliant sheet metal assemblies are often used as support structures in automobiles, airplanes and appliances. These structures not only provide a metrology frame for other modules to be assembled, but also give the product its aesthetic form. For this reason, the dimension quality of the assemblies is a very important factor to control, in order to make sure that the product will function as planned and continuously keep the product cost low. The assembly is influenced by variations in the component parts and the assembly processes. Tolerance analysis, as conducted in most industries today, is normally based on the assumption of rigid parts and is thus not always valid for sheet metal assemblies, due to their compliance. This paper will present a method, based on finite element analysis (FEA) and design of computer experiments, of identifying the influence of input variables on the final geometry variation of the assembly. The influence and the interactions among the input variables are analyzed with a response model that has been constructed, using the simulation results. This response model could be used to identify the important variables that need to be controlled in assembly. An example application is included, in order to demonstrate the simulation model and response model construction. Analysis of the results from the simulations can facilitate the design of the assembly process, in order to control the dimensional quality of the product.

Abstract Reverse engineering (RE), may be defined as the process of generating computer aided design models (CAD) from existing or prototype parts. The process has been used for many years in industry. It has markedly increased in implementation in the past few years, primarily due to the introduction of rapid part digitization technologies. Current industrial applications include CAD model construction from artisan geometry, such as in automotive body styling, the generation of custom fits to human surfaces, and quality control. This paper summarizes the principles of operation behind many commercially available part digitization technologies, and discusses techniques involved in part digitization using a coordinate measuring machine (CMM) and laser scanner. An overall error characterization of the laser scanning digitization process is presented for a particular scanner. This is followed by a discussion of the merits and considerations involved in generating combined data sets with characteristics indicative of the design intent of specific part features. Issues in facilitating the assembly, or registration, of the different types of data into a single point set are discussed.

In 2009 the United States Nuclear Regulatory Commission (NRC) will issue Regulatory Guide 1.28 [1] endorsing the Nuclear Quality Assurance (NQA) Standard, NQA-1-2008 Edition with NQA-1a-2009 Addenda [2] as the appropriate quality assurance (QA) requirements for the design, construction and operation of new and existing U.S. nuclear generating facilities. This endorsement will change the U.S. regulatory QA position from NQA-1-1994 and incorporate 15 years of quality experience, lessons learned, technology enhancements and regulatory changes. This regulatory position change will subsequently be included in a revision to the NRC’s NUREG-0800, Standard Review Plan (SRP) 17.5, Quality Assurance Program Description – Design Certification, Early Site Permit and New License Applicants [3]. The Nuclear Energy Institute’s NEI 06-14A, Quality Assurance Program Description (QAPD) [4], which provides a generic QA template for use by new generation early site permit and combined license applicants for implementing QA regulatory requirements of SRP 17.5 will subsequently be revised to document the new regulatory position for the use of NQA-1a-2009. These new quality requirements will be passed on by the utilities constructing new generating facilities to the both U.S. and international suppliers, thus changing the basis of QA requirements for the nuclear industry. The NQA-1 Standard is a four-part criteria standard that provides quality requirements and acceptance criteria for the implementation of a nuclear facility quality assurance program. Part I describes the basic QA program elements and Part II provides requirements for specialized support and application activities for design, construction and operations. Part III contains guidance that support Parts I and II, and Part IV provides guidance for comparison of NQA-1 with other quality standards. This paper will focus on the background of the quality changes included in the endorsement on NQA-1-2008 with the NQA-1a-2009 Addenda and provide a detailed discussion of the following major changes: • Facility configuration control – measures to ensure changes that may affect the approved facility configuration are recognized and processed. • Engineering interface controls – controls to ensure interfaces for design changes are established among design organizations. • Software design controls – alternate design measures specifically for software design to ensure design input, design processes, verification and change control are appropriately performed. • Software application requirements – controls for the software engineering requirements for the acquisition, development, operation, maintenance, and retirement of software. • Electronic records – controls that address use of electronic media for QA record activities. • Commercial grade items – a composite document of criteria for the identification and dedication of commercial grade items and services. • Clarifications for consistency of basic QA requirements – areas in the Standard where the QA text needed to be return to basic principles and to add clarification to ensure national and international consistent application.

Abstract The quality of AM built parts is highly correlated to the melt pool characteristics. Hence melt pool monitoring and control can potentially improve AM part quality. This paper presents a neighboring-effect modeling method (NBEM) that uses scan strategy to predict melt pool size. The prediction model can further assist in scan strategy optimization and real-time process control. The structure of the proposed model is formulated based on the physical principles of melt pool formation, while experimental data is used to identify the optimal coefficients. Compared to the traditional power-velocity prediction models, NBEM model introduces the cumulative neighboring-effect factors as additional input variables. These factors represent the neighborhood impact of scan path on the focal point melt pool formation from time and distance perspective. Two experiments use different scan strategies to collect in-situ measurements of melt pool size for model construction and validation. By introducing the neighboring-effect factors, the global Normalized Root Mean Square Error (NRMSE) is improved from around 0.10 to 0.08. More importantly, the local NRMSE of irregular melt pool area prediction is improved to around 0.15 for more than 50% improvement. The case studies verify that the proposed method can predict the melt pool variations by seamlessly integrating scan strategy considerations.

Additive Manufacturing (AM) processes have vastly improved over the years and 3D-printed parts are no longer solely being used for prototyping but also as final products. Where AM parts are used in low-volume products, nondestructive testing is critical to validate product performance. This paper will discuss using an infrared thermography technique known as Pulsed Thermography (PT) based on the analysis of a theoretical one-dimensional solution as a nondestructive testing method for quantitatively measuring defect depths within a 3D-printed part made from a thermoplastic ABS. This method has previously been applied to composites, ceramics, and metals for quantification of defects, but no work has been done for thermoplastic 3D printed parts. This technique can potentially be integrated into existing equipment for online monitoring during part construction. This paper will demonstrate the ability of a low-cost PT system to characterize the surface of 3D-printed parts and detect the effect of common parameter variations. The capability of a PT system as a viable NDT method to quantitatively analyze a 3D-printed part would allow for post process quality control in comparison to initial design and simulation.

The construction of the Pelješac bridge is a capital project of the Republic of Croatia with the support of the EU, thus realizing the long-standing plan of establishing a strong road connection of all parts of Croatian territory. Prior to the construction of the Pelješac Bridge, the land of the territory of the Republic of Croatia was separated, which belongs to neighboring Bosnia and Herzegovina, and on a road distance of 9.25 kilometers had to cross the state border twice, which during the summer months due to the tourist season led to large traffic jams. The separation of state territory has made it difficult to invest in infrastructure in the south, and economic and tourism progress has been slow. The construction of the bridge with the accompanying infrastructure will enable the road connection of the previously separated land parts of the Croatian territory. The Pelješac Bridge is one of four phases of a much larger and more complex project called "Road Connection with Southern Dalmatia". As part of this project, a total of 32.53 kilometers of roads will be built with accompanying facilities (viaducts, bridges, tunnels, underpasses, rest areas and reservoirs). The goals that will be achieved by this project are to increase the level of transport system service and traffic safety and to shorten road travel between northern and southern Croatia. The paper provides an overview of all details of planned and constructed sections according to the main project of the Pelješac bridge and its access roads, the process of structural design of pavement structure with reference to the program of quality control and quality assurance of materials and works.

Abstract Test fixtures are widely used in industry for quality control to determine the potential of a product to make excessive noise. Since acceptable parts may be rejected unnecessarily, or noisy parts may be passed if the test is inaccurate, it is desirable to have a reliable test setup, including the test fixture. When the part being tested is a motor and gearbox, and the test measurement is vibration, the vibratory response may vary significantly, depending on exactly how the motor and gear tones line up with the test fixture resonances. This potential for variability has led to vibration test fixtures being designed to be as precise as possible, so that the construction of the test fixture can be repeated from one application to the next. However, such an approach has led to rather stiff and massive designs, with few resonant modes, with the result that the repeatability of the measurements can be affected by rather small variations in motor speed and mounting conditions. A similar situation in acoustics leads to the use of reverberation chambers with rotating diffusers. This paper describes an investigation into the possibility of employing a vibration analog to the reverberant room as a test fixture, in order to make vibration measurements on a production line more reliable. The fixture is a plate, sized to achieve a higher modal density than exists in a typical test fixture. The geometry, edge restraints and interior loads are varied, either through analysis or experiments, to produce a variability of response to be averaged over during the data analysis period. Our conclusion is that the reverberant plate test fixture is able to reduce the variability of vibrational response in comparison to a more standard test fixture.

With deepening ocean development , a larger scale Internet of Underwater Things (IoUT) is being realized[1].More and more underwater equipment is being deployed, various ocean monitoring equipment, underwater robots and underwater group sites amongst others, all of which will be working in the deep sea for long periods of time in the foreseeable future[2].Due to the increasing working time and power consumption, it has become difficult for the high energy batteries carried by these facilities to cover their energy needs [3]. Therefore, it is necessary to solve the problem of electrical energy replenishment for underwater equipment.Based on Equinor’s Underwater Intervention Drone (UID) standard interface definition, Blue Logic have produced the world's first three universal, open-standard subsea drone docking stations.But this is not perfect, in the face of deeper waters, more complex multi-shape deep sea equipment charging needs, the current program is not enough to solve[4].Therefore, based on the IoUT scenario positioning, this research designs a subsea charging station that can serve multiple devices.The concept is similar to a land-based collection station for power banks, providing multiple sub-charging equipment that can be carried on the move to charge multiple subsea equipments of different types simultaneously.It also uses ocean energy to provide in-situ produced electricity for the underwater charging base station .Compared to Blue Logic's Subsea Drone Docking Station (SDS), it enables the multi-device charging needs of the IoUT using ultrasonic technology[5,6].In the long term, the combination of existing equipment will greatly reduce the cost of regional subsea long-term exploration and expand the scope of exploration[7].The paper will solve the following problems:1) How to solve the charging problem of long-distance survey of underwater equipments（e.g. AUV）?2) How to make the design applicable to charging usage scenarios common to different types, forms and sizes of underwater equipments?3) How to design underwater charging energy transmission more efficiently and sustainably?The research approach composed following parts:- Through literature research, sort out the development status of technical equipment such as underwater charging, underwater docking, underwater information transmission and marine power generation.- A structure interview with the opinions of deep-sea equipment designers and researchers to clarify the design requirements. - Analyze product features and problems and summarize the design process and direction through brainstorming method and solution building method.The design of the underwater multi-port charging base station solves the energy problem of deep-sea long-term survey equipment, with poor energy sustainability and low charging efficiency.This approach will enable true continuous subsea operations in extremely dynamic ocean environments.Although the project is still a conceptual design and various sensors are still being experimented with, it is forward-looking and instructive for future applications.References1.Wang X., Lu J., Peng W., &Song L.,(2021) Accelerating the construction of marine "new infrastructure" and promoting high-quality development of marine industry,Science & Technology Review,39(16),pp.76-80.2.Qu, Feng-Chong, Lai. , Liu, J.-Z., Tu, X.-B., Jiang, Y.,(2021)'Research and Application of Key Technologies for Marine Internet of Things', Telecommunications Science, 37, (7), pp. 25-33.3.Tian Y., Yuan R.,&Li X.,(2018)'Design and experiment of deep-sea microcurrent power generation system', Acta Energiae Solaris Sinica,Journal of China Academy of Electronics and Information Technology, 39, (4), pp. 873-878.4.SubseaDockingStation(SDS).[Online].Available:https://www.bluelogic.no/news-and-media/subsea-docking-station-sds-.5.Abicht, D., Torvestad, J.C., Solheimsnes, P.A., and Stenevik, K.A., ‘Underwater Intervention Drone Subsea Control System’, in Proceedings of the OTC, 2020.6.Wang Y., &Tian F.,(2019)'Research on acoustic wave-based charging planning in underwater sensing networks',Journal of China Academy of Electronics and Information Technology,14(11),pp.1183-11877.Cruz, N.A., Matos, A.C., Almeida, R.M., and Ferreira, B.M.: ‘A lightweight docking station for a hovering AUV’, in Proceedings of the IEEE, 2017, pp. 1-7.

Abstract The worldwide demand for electricity is continually increasing. Deregulation in the power generation business is driving rapid changes in the global energy market. This results in higher premiums on steam turbine efficiency and opportunities to structure several new Steam Turbine products to meet these challenging requirements. The “Dense Pack” high pressure section replacement and offering is one of the newest advanced designs to address these needs by delivering more power for the least amount of fuel. The intense competition to serve the electric power utility industry combined with the drive for new product introductions to be of the highest development life-cycle quality demands that verification of performance benefits be established very early in the new product development process. To answer this and establish pre-field installation credibility with customers, a new multi-stage Steam Turbine Test Vehicle (STTV) has been designed and constructed. The turbine faithfully models a typical, 4-admission, large utility steam turbine and preserves geometric and flow similarity while operating at reduced pressure. The basic train is comprised of a nominal 3.5 MW (4700 hp) test turbine, a 5:1 speed reducing load gear, and two tandem 3.0 MW (4000 hp) dynamometers. The thermodynamic cycle is straight through superheated steam entering the turbine through a turbine bowl pressure regulator control valve and exhausted to the atmosphere via a back pressure control valve and roof-mounted silencer. A rigorous Design for Six Sigma (DFSS) process was used to establish the test turbine facility and to ensure all of the new product program objectives were met. A detailed description of the facility is given with discussion of the major sub-systems, prototypical model hardware, unique steampath instrumentation, and the test procedures used to ensure accurate, repeatable data. The timeline for accomplishing the design, construction, and early testing is chronicled. Key test results are summarized including baseline testing to validate the new test facility, testing of the “Dense Pack” aerodynamic design methodology for power generation steam turbines, and the performance evaluation of developments such as new shaft, advanced aerodynamics and bucket tip seals. In addition to developing the new design technologies and verifying their predicted efficiency increases, the Steam Turbine Test Vehicle is key for conducting Form-Fit-Function studies. Model hardware built using the standard manufacturing methods and materials intended for production parts provides invaluable insight ahead of finalizing production specifications. New features such as advanced seals and Integral Cover Buckets (ICB) benefit from being more thoroughly understood in terms of assembly and procedures ahead of new product production.

Increased research into the chemistry, physics and material science of hydrogen cycling compounds has led to the rapid growth of solid-phase hydrogen-storage options. The operating conditions of these new options span a wide range: system temperature can be as low as 70K or over 600K, system pressure varies from less than 100kPa to 35MPa, and heat loads can be moderate or can be measured in megawatts. While the intense focus placed on storage materials has been appropriate, there is also a need for research in engineering, specifically in containment, heat transfer, and controls. The DOE’s recently proposed engineering center of expertise underscores the growing understanding that engineering research will play a role in the success of advanced hydrogen storage systems. Engineering a hydrogen system will minimally require containment of the storage media and control of the hydrogenation and dehydrogenation processes, but an elegant system design will compensate for the storage media’s weaker aspects and capitalize on its strengths. To achieve such a complete solution, the storage tank must be designed to work with the media, the vehicle packaging, the power-plant, and the power-plant’s control system. In some cases there are synergies available that increase the efficiency of both subsystems simultaneously. In addition, system designers will need to make the hard choices needed to convert a technically feasible concept into a commercially successful product. Materials cost, assembly cost, and end of life costs will all shape the final design of a viable hydrogen storage system. Once again there is a critical role for engineering research, in this case into lower cost and higher performance engineering materials. Each form of hydrogen storage has its own, unique, challenges and opportunities for the system designer. These differing requirements stem directly from the properties of the storage media. Aside from physical containment of compressed or liquefied hydrogen, most storage media can be assigned to one of four major categories, chemical storage, metal hydrides, complex hydrides, or physisorption. Specific needs of each technology are discussed below. Physisorption systems currently operate at 77K with very fast kinetics and good gravimetric capacity; and as such, special engineering challenges center on controlling heat transfer. Excellent MLVSI is available, its cost is high and it is not readily applied to complex shape in a mass manufacture setting. Additionally, while the heat of adsorption on most physisorbents is a relatively modest 6–10kJ/mol H2, this heat must be moved up a 200K gradient. Physisorpion systems are also challenged on density. Consequently, methods for reducing the cost of producing and assembling compact, high-quality insulation, tank design to minimize heat transfer while maintaining manufacturability, improved methods of heat transfer to and from the storage media, and controls to optimize filling are areas of profitable research. It may be noted that the first two areas would also contribute to improvement of liquid hydrogen tanks. Metal hydrides are currently nearest application in the form of high pressure metal hydride tanks because of their reduced volume relative to compressed gas tanks of the same capacity and pressure. These systems typically use simple pressure controls, and have enthalpies of roughly 20kJ/mol H2 and plateau pressures of at most a few MPa. During filling, temperatures must be high enough to ensure fast kinetics, but kept low enough that the thermodynamically set plateau pressure is well below the filling pressure. To accomplish this balance the heat transfer system must handle on the order of 300kW during the 5 minute fill of a 10kg tank. These systems are also challenged on mass and the cost of the media. High value areas for research include: heat transfer inside a 35MPa rated pressure vessel, light and strong tank construction materials with reduced cost, and metals or other materials that do not embrittle in the presence of high pressure hydrogen when operated below ∼400K. The latter two topics would also have a beneficial impact on compressed gas hydrogen storage systems, the current “system to beat”. Complex hydrides frequently have high hydrogen capacity but also an enthalpy of adsorption >30kJ/mol H2, a hydrogen release temperature >370K, and in many cases multiple steps of adsorption/desorption with slow kinetics in at least one of the steps. Most complex hydrides are thermal insulators in the hydrided form. From an engineering perspective, improved methods and designs for cost effective heat transfer to the storage media in a 5 to 10MPa vessel is of significant interest, as are materials that resist embrittlement at pressures below 10MPa and temperatures below 500K. Chemical hydrides produce heat when releasing hydrogen; in some systems this can be managed with air cooling of the reactor, but in other systems that may not be possible. In general, chemical hydrides must be removed from the vehicle and regenerated off-board. They are challenged on durability and recycling energy. Engineering research of interest in these systems centers around maintaining the spent fuel in a state suitable for rapid removal while minimizing system mass, and on developing highly efficient recycling plant designs that make the most of heat from exothermic steps. While the designs of each category of storage tank will differ with the material properties, two common engineering research thrusts stand out, heat transfer and structural materials. In addition, control strategies are important to all advanced storage systems, though they will vary significantly from system to system. Chemical systems need controls primarily to match hydrogen supply to power-plant demand, including shut down. High pressure metal hydride systems will need control during filling to maintain an appropriately low plateau pressure. Complex hydrides will need control for optimal filling and release of hydrogen from materials with multi-step reactions. Even the relatively simple compressed-gas tanks require control strategies during refill. Heat transfer systems will modulate performance and directly impact cost. While issues such as thermal conductivity may not be as great as anticipated, the heat transfer system still impacts gravimetric efficiency, volumetric efficiency and cost. These are three key factors to commercial viability, so any research that improves performance or reduces cost is important. Recent work in the DOE FreedomCAR program indicates that some 14% of the system mass may be attributed to heat transfer in complex hydride systems. If this system is made to withstand 100 bar at 450K the material cost will be a meaningful portion of the total tank cost. Improvements to the basic shell and tube structures that can reduce the total mass of heat transfer equipment while maintaining good global and local temperature control are needed. Reducing the mass and cost of the materials of construction would also benefit all systems. Much has been made of the need to reduce the cost of carbon fiber in compressed tanks and new processes are being investigated. Further progress is likely to benefit any composite tank, not just compressed gas tanks. In a like fashion, all tanks have metal parts. Today those parts are made from expensive alloys, such as A286. If other structural materials could be proven suitable for tank construction there would be a direct cost benefit to all tank systems. Finally there is a need to match the system to the storage material and the power-plant. Recent work has shown there are strong effects of material properties on system performance, not only because of the material, but also because the material properties drive the tank design to be more or less efficient. Filling of a hydride tank provides an excellent example. A five minute or less fill time is desirable. Hydrogen will be supplied as a gas, perhaps at a fixed pressure and temperature. The kinetics of the hydride will dictate how fast hydrogen can be absorbed, and the thermodynamics will determine if hydrogen can be absorbed at all; both properties are temperature dependent. The temperature will depend on how fast heat is generated by absorption and how fast heat can be added or removed by the system. If the design system and material properties are not both well suited to this filling scenario the actual amount of hydrogen stored could be significantly less than the capacity of the system. Controls may play an important role as well, by altering the coolant temperature and flow, and the gas temperature and pressure, a better fill is likely. Similar strategies have already been demonstrated for compressed gas systems. Matching system capabilities to power-plant needs is also important. Supplying the demanded fuel in transients and start up are obvious requirements that both the tank system and material must be design to meet. But there are opportunities too. If the power-plant heat can be used to release hydrogen, then the efficiency of vehicle increases greatly. This efficiency comes not only from preventing hydrogen losses from supplying heat to the media, but also from the power-plant cooling that occurs. To reap this benefit, it will be important to have elegant control strategies that avoid unwanted feedback between the power-plant and the fuel system. Hydrogen fueled vehicles are making tremendous strides, as can be seen by the number and increasing market readiness of vehicles in technology validation programs. Research that improves the effectiveness and reduces the costs of heat transfer systems, tank construction materials, and control systems will play a key role in preparing advanced hydrogen storage systems to be a part of this transportation revolution.