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Articles de revues sur le sujet "VIBRATORY LOADING"
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Lacoste, F. Rocher, et M. P. Bourdouxhe. « Behaviour of impact- and vibratory-driven piles in stiff clay during installation and static loading ». Journal of Nepal Geological Society 34 (9 octobre 2006) : 17–24. http://dx.doi.org/10.3126/jngs.v34i0.31874.
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This paper summarises the results of an extensive field test carried out in the framework of the "French National Research Project on Vibratory Driving" and the ProfilArbed Research Programme, to investigate and compare the behaviour and performance of eight impact- and vibratory-driven piles. The test site is located in Northern France. The subsoil consists of dense Flanders clay. The piles were driven using an ICE8 l5 vibrator and an IHC70s impact hammer to the same depth. All these piles were instrumented with accelerometers and strain gauges positioned at the top and bottom of the piles. Penetration rate, uplift load applied by the crane, vibration transmitted to the ground, operating pressure, oil flow at the vibratory power-pack, and energy per blow for the hammer were continuously recorded. The paper presents the main results obtained from double sheet piles (AUl6 type) driven to 7 m depth, a small wall of two double sheet piles (AU20 type) driven to 8 m depth, HP bearing piles driven to 10.2 m, and steel open-ended tubes of508 mm diameter driven to 9.4 m depth. After a delay of 6 to 8 weeks, the piles were statically loaded to failure. The piles were instrumented with removable extensometers, which made it possible to measure the mobilisation of shaft friction and toe resistance. The measured bearing capacity was significantly lower for the vibratory-driven piles (around 35%) and it is consistent with the results obtained by the Laboratoire des Ponts et Chaussees de Paris at other sites.
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Wang, Jijing, et Zhihua Tan. « Mechanical and Mesoscale Analyses of Cement Stabilized Macadam Prepared by Vibratory and Nonvibratory Mixing Techniques ». Advances in Civil Engineering 2021 (9 février 2021) : 1–13. http://dx.doi.org/10.1155/2021/6663233.
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The objective of this study is to analyze the effects of mixing techniques on the mechanical behavior and meso-structure of cement-treated aggregate. Different specimens were prepared by vibratory and nonvibratory mixing techniques. X-ray CT scans were performed to illustrate the distribution of cement mortar on aggregate. The strength, modulus, and fatigue tests under different stress states were tested to reveal the impacts of mixing techniques. Then, the relationships between strengths and loading rates and that between moduli and stress levels were established. Hereafter, the S-N fatigue equation that modified with stress ratio related to loading rates was used to describe the fatigue performance. The results indicate that the cement mortar of specimens prepared by vibratory mixing was well-distributed on aggregates. The strength, modulus, and fatigue life of the specimens prepared by vibratory mixing were higher under the test condition threshold. Moreover, the growth rate of strength and modulus with loading for specimens prepared by vibratory mixing was slightly larger than that for specimens prepared by nonvibratory mixing. Compared with the cement-treated aggregates specimens prepared by nonvibratory mixing, the fatigue life of cement-treated aggregates specimens prepared by vibratory mixing had more stable stress sensitivity.
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Nadutyi, V. P., et E. C. Lapshin. « Probabilistic simulation of vibratory screening under high loading conditions ». Refractories and Industrial Ceramics 45, no 6 (novembre 2004) : 453–56. http://dx.doi.org/10.1007/s11148-005-0033-2.
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de Montaudouin, J., N. Reveles et M. J. Smith. « Computational aeroelastic analysis of slowed rotors at high advance ratios ». Aeronautical Journal 118, no 1201 (mars 2014) : 297–313. http://dx.doi.org/10.1017/s0001924000009131.
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Abstract The aerodynamic and aeroelastic behaviour of a rotor become more complex as advance ratios increase to achieve high-speed forward fight. As the rotor blades encounter large regions of cross and reverse flows during each revolution, strong variations in the local Mach regime are encountered, inducing complex elastic blade deformations. In addition, the wake system may remain in the vicinity of the rotor, adding complexity to the blade loading. The aeroelastic behaviour of a model rotor with advance ratios ranging from 0·5 to 2·0 has been evaluated with aerodynamics provided via a computational fluid dynamics (CFD) method. Significant radial blade-vortex interaction can occur at a high advance ratio; the advance ratio at which this occurs is dependent on the rotor configuration. This condition is accompanied by high vibratory loads, peak negative torsion, and peak torsion and in-plane loads. The high vibratory loading increases the sensitivity of the trim model, so that at some high advance ratios the vibratory loads must be filtered to achieve a trimmed state.
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Dyrda, Vitalii, Anatolii Kobets, Viktor Pukhalskyi, Yurii Kozub et Oleksandr Chernii. « Dynamics of vibratory partitioned feeders for the uranium ore drawing and feeding ». E3S Web of Conferences 109 (2019) : 00023. http://dx.doi.org/10.1051/e3sconf/201910900023.
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In this paper, the authors consider dynamics of partitioned vibratory feeders with rubber elastic couplings. Use of vibratory feeders (including partitioned ones) and schemes for the ore vibrating drawing, feeding and loading in underground conditions allowed to mechanize one of the most time-consuming and dangerous processes of uranium ore mining and to solve the following problems: to improve effectiveness of the lumpy rock mass drawing and loading by 2.5-3 times; to increase intensity of mining operations and reduce life of the excavation blocks and horizons; to reduce labor intensity and cut cost of the process of ore drawing and loading; to improve uniformity of the rock-mass outflowing from the discharge opening and to reduce by 3-5 times frequency of the large-lump material freezing (use of partitioned feeders reduces number of freezes by 25-60 times); to increase size of commercial lump panels; practically to exclude traumas during the process of ore drawing and loading (usually, it presents 30-60 % of all traumas caused by the underground operations); to mechanize process of ore drawing and loading, and to create conditions for implementation of low-waste cyclic-and-continuous mining technology.
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Gu, Li Zhi, et T. Lee. « Dynamic Stress Intensity Factor with Griffith – II Type Crack in Vibratory Machining and its Influence on Chip Formation ». Applied Mechanics and Materials 10-12 (décembre 2007) : 939–44. http://dx.doi.org/10.4028/www.scientific.net/amm.10-12.939.
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Reviewed the achievements and advances in the vibratory metal machining, analyzed the features and mechanics in microstructure with SEM. The dynamic stress intensity factor is derived on the basis of fracture mechanics and stress-wave theory with the Griffith- II type sliding-open crack.. Comparison between the vibratory machining and the conventional machining has been made with brass on lathe CW6150B, with computer controlled piezoelectric ceramic micro-drive system and cutting forces and surface texture of the specimen were observed. The dynamic stress intensity factor was discussed and it was found that the value of dynamic stress intensity factor may be high with response to the Heaviside impulsive loading, indicating the reason why vibratory machining has better comprehensive results than the conventional one does.
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David Suits, L., TC Sheahan, MA Mooney et CO Bouton. « Vibratory Plate Loading of Compacted and Instrumented Field Soil Beds ». Geotechnical Testing Journal 28, no 3 (2005) : 12448. http://dx.doi.org/10.1520/gtj12448.
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Sobczyk, Kazimierz, Kyriakos Perros et Costas Papadimitriou. « Fatigue Reliability of Multidimensional Vibratory Degrading Systems under Random Loading ». Journal of Engineering Mechanics 136, no 2 (février 2010) : 179–88. http://dx.doi.org/10.1061/(asce)em.1943-7889.0000052.
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Bespalov, A. L., I. G. Svidrak et O. O. Boiko. « Improving the performance of vibration feeders with an electromagnetic vibration drive and a combined vibration system ». Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 22, no 93 (13 mai 2020) : 26–30. http://dx.doi.org/10.32718/nvlvet-f9305.
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Vibration loading devices are widely used in various branches of mechanical engineering to load piece blanks of automatic machines and automatic lines as well as robotic systems, automated systems and flexible automated production. Vibration devices for transportation and loading of miniature, small and medium-sized products are the most widely used. Modern designs of vibratory feeders, made according to the classical dynamic scheme and having a two-mass oscillating system, do not fully use the energy of the vibratory exciter to perform useful work. In addition, due to the presence of a heavy reactive mass, they have a fairly large weight. When the vibrating feeder is operating, the energy of the vibration exciter is spent on pumping both the hopper, which performs useful work, and the reactive plate, which performs idle vibrations. Thus, part of the energy of the vibration exciter is not used for performing useful work, but is spent idly. To increase the efficiency of the device, increase its performance and reduce its weight and metal consumption, it is necessary to change the design of the vibratory feeder and some of its elements, which affect the redistribution of the oscillation amplitudes of the working (hopper) and reactive mass of the vibratory feeder. Modern production involves the creation of new models of machines with high technical and economic indicators, therefore, improving the efficiency of existing equipment and the development of new schemes of machines is an important task for designers and manufacturers of technological equipment, as the minimum improvement of its technological and operational performance can lead to a tangible economic effect. To solve this problem we developed a new design vibrating hopper feeder, in which the increase of the horizontal component of the oscillation amplitude of the working element (hopper) is not at the expense of increased power of the vibratory exciter, but due to internal redistribution of energy between the elements of the oscillating system that makes better use of the energy of the vibratory exciter to perform useful work, i.e. to increase the coefficient of useful action. In addition, the weight and metal content of the vibrating feeder structure are simultaneously reduced.
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Yamazaki, Satoru, Paul S. Weinhold, Ronald D. Graff, Mari Tsuzaki, Mamoru Kawakami, Joe T. Minchew et Albert J. Banes. « Annulus cells release ATP in response to vibratory loading in vitro ». Journal of Cellular Biochemistry 90, no 4 (24 octobre 2003) : 812–18. http://dx.doi.org/10.1002/jcb.10681.
Texte intégralThèses sur le sujet "VIBRATORY LOADING"
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Soelarso, Soelarso. « On the finite element analysis and design of the spider net system footing (SNSF) considering static and seismic loadings ». Thesis, Compiègne, 2021. https://bibliotheque.utc.fr/Default/doc/SYRACUSE/2021COMP2656.
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Cette thèse est consacrée à la compréhension approfondie du comportement mécanique de fondations superficielles de bâtiments construits sur sols relativement mous en s’appuyant sur des modélisations numériques par éléments finis tridimensionnels. Les fondations superficielles concernées permettent une diffusion et transferts de charges de type « toile d’araignée » ou « pieds de poule », fréquemment utilisés en Indonésie et appelés Spider Net System Footing (SNSF). Ces types de fondation sont adaptées aux sols mous mais aussi aux sollicitations de type tremblement de terre. Elles ont été très peu étudiées d’un point de vue scientifique. L’approche de modélisation par éléments finis en élasticité tridimensionnelle est bien adaptée aux couplages de la fondation avec la structure supérieure et avec le sol de support. Après validation des modèles éléments finis en comparant nos résultats avec des approches numériques et expérimentales existantes, nous proposons deux types d’analyses s’appuyant sur des données géométriques, mécaniques et matérielles d’une construction récente sur l’ile de Java, Province de Banten. Le premier type de modélisations permet une analyse fine du comportement statique d’une cellule de fondation avec deux poteaux, soumise à des charges verticales. Le second type de modélisations permet d’estimer les fréquences propres de vibrations libres et d’étudier le comportement d’une cellule de fondation représentative soumise à des actions sismiques, traduites en sollicitations sous charges latérales équivalentes. Les travaux incluent non seulement des analyses détaillées avec des données existantes mais aussi une proposition de dimensionnement pour projets futurs. Par ailleurs le rôle de la fondation et du sol support sur la rigidité axiale, sur les fréquences de vibration et sur la rigidité en flexion ont fait l’objet d’une attention particulière.Toutes les analyses (ou presque) ont été réalisées à l’aide des modules de la suite Hyperworks d’Altair (Hypermesh, Optistruct)This thesis is devoted to a thorough understanding of the mechanical behavior of shallow foundations of buildings built on relatively soft soils, based on three-dimensional finite element numerical modelling. The shallow foundations involved allow the diffusion and transfer of loads, as for "spider webs" or "chicken feet". They are frequently used in Indonesia and called Spider Net System Footing (SNSF). These types of foundations are suitable for soft soils but also resistant under earthquake actions. They have little been studied from a scientific point of view. The finite element modeling approach in three-dimensional elasticity is well suited to take into account the couplings of the foundation with the upper structure and with the supporting soil. After validation of our finite element models by comparing our results with existing numerical and experimental ones, we propose two types of analyses based on geometric, mechanical and material data extracted from of a recent construction on the island of Java, Province of Banten. The first type of analyses allows fine relevant modelling of the static behavior of a foundation cell with two columns, subjected to vertical gravity loads. The second type of modelling makes it possible to estimate the frequencies of free vibrations and to study the behavior of a representative foundation cell subjected to seismic actions, under equivalent lateral loads via the Elastic Response Spectrum Approach. The present work includes not only detailed analyses with existing data but also a design proposal for future projects. Special attention is also paid to the role of the foundation and the supporting soil on the axial rigidity, vibration frequencies and bending stiffness. Almost all finite element analyses have been done using the Hyperworks software from Altair (Hypermesh, Optistruct)
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BOBAN, AMMU. « DYNAMIC ANALYSIS OF CONFINED GEOMATERIAL SUBJECTED TO VIBRATORY LOADING ». Thesis, 2023. http://dspace.dtu.ac.in:8080/jspui/handle/repository/20018.
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The reinforcement using single-layer geogrid on a confined geomaterial is an effective
way of solving practical problems. With the use of multi-layered reinforcement, this study
aims to offer a superior alternative design for supporting heavy loads on geomaterial. The
location of reinforcement plays a crucial role in the overall strength. The experimental
investigations were conducted on poorly graded sand (SP) whose angle of internal friction
and cohesion are 36.6º and 4.4 kPa, respectively. The effect of single-layer geogrid
reinforcement placed at different depths of the geomaterial was evaluated. Further, the
bearing capacity of the geomaterial was compared for single, double and triple-layered
geogrid reinforcement. A laboratory Digital Static Cone Penetration Test (DSCP) was
performed to assess the load-displacement behaviour of unreinforced and reinforced
geomaterial. The result shows that reinforced geomaterial achieved higher resistance
compared to unreinforced systems. An optimum combination of placement depths of
double-layered reinforcement is proposed.
Additionally, the dynamic response of the confined geomaterial subjected to vibratory
load has been investigated using a numerical program supported by experimental
findings. An accelerometer has been used to report the acceleration, velocity, and
displacement of confined geomaterial fill along the depth at varied frequencies of
vibratory load. Further, the experimental findings were used in the numerical program to
obtain the shear modulus and damping of confined geomaterial. The stress-strain response
shows compounded effects with an increase in frequency and modulus of elasticity. It has
been observed that displacement is amplified by 10-90 % for a frequency range of 5-75
iv
Hz. The shear stress-strain results showed that the shear modulus is magnified by 50 %
for varied input parameters considered in the study. The damping of the confined
geomaterial has been found to be 0.5-5 % for varied unit weight inputs (16 - 22 kN/m3
).
The results are compared with the outputs obtained by numerical simulation and
experimental analysis for estimating the dynamic properties of the confined geomaterial
subjected to vibratory load.
Further, the study utilized various numerical simulation and experimental data to train
and evaluate different models to generate predictions. These predictions were essential
for the research. The models employed included ensemble boosted tree, squared
exponential Gaussian Process Regression (GPR), Matern 5/2 GPR, exponential GPR, and
decision tree architectures (fine and medium). These models greatly facilitated the
analysis of the collected data and enabled accurate result predictions. Among the
examined models, the Matern 5/2 GPR model exhibited exceptional accuracy with an R2
value of 0.99, demonstrating its remarkable predictive capability. The outcomes highlight
the proficiency of the Matern 5/2 GPR and Boosted Tree models in forecasting
displacement patterns and enhancing the comprehension of the relationship between
displacement and depth. The outcomes of the present study can effectively be adopted by
engineers and partitioners for estimating the dynamic properties of the confined
geomaterial in construction practices.
Chapitres de livres sur le sujet "VIBRATORY LOADING"
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Fressinet, M., F. Fuchs et P. Madelpech. « Fatigue Life Estimation of Structures Subjected to Vibratory Loading ». Dans ICAF 2011 Structural Integrity : Influence of Efficiency and Green Imperatives, 427–42. Dordrecht : Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-1664-3_34.
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du Plooy, N. F., et P. S. Heyns. « Reducing Vibratory Screen Structural Loading Using a Vibration Absorber ». Dans Structural Engineering, Mechanics and Computation, 905–12. Elsevier, 2001. http://dx.doi.org/10.1016/b978-008043948-8/50100-4.
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Honcharuk, Inna, et Ihor Kupchuk. « STUDY OF MECHANICAL-RHEOLOGICAL PARAMETERS OF FEED GRAIN DURING TO THE IMPACT-CUTTING LOADING ». Dans Theoretical and practical aspects of the development of modern scientific research. Publishing House “Baltija Publishing”, 2022. http://dx.doi.org/10.30525/978-9934-26-195-4-15.
Texte intégralRésumé :
The research is based on the tasks of applied research on the topic: «Development of a complex of energy-efficient and resource-saving equipment and promising technologies for feeding farm animals of the AIC of Ukraine», state registration number 0121U108589. The authors’ research is aimed at solving current problems of technological renewal and development of the agro-industrial complex of Ukraine. Rationalisation of energy use necessitates the substantiation of the energy-saving variant by implementing energy-efficient machines and technologies in the system of feed preparation and feeding animals. Grinding largely determines the quality of compound feed, its digestibility by animals and birds, and has a significant impact on the growth of animal productivity, the profitability of the enterprise, the rhythm of work and production costs. Therefore, reducing the energy intensity of the process is an urgent task. In the laboratory of the theory of mechanisms and machines of the department of general technical disciplines and labor protection of Vinnitsa National Agrarian University, a vibratory disk crusher was designed to increase the level of technical support for the livestock industry. The crusher uses a more efficient method of grinding feed grain – a combination of impact and cutting, in contrast to a hammer mill that grinds with a free impact of hammers. Further improvement of the energy efficiency of grain grinding in a vibratory crusher requires theoretical studies of the process dynamics and determination of the minimum amount of energy required to break the grain. An effective and modern method for studying complex objects is system analysis, which makes it possible to modernize existing and design new machines without a large number of expensive physical experiments. The implementation of effective energy saving measures requires a deep theoretical study of the interaction of the material with the impact element of the crusher. Modelling for the grinding operation, it is necessary to consider structural-mechanical properties of the product, its ability to deform in different modes of interaction with the executive body of the technological machine. The total mechanical work expended on the destruction of the material and and energy intensity of the feed preparation process depends on this deformation. The aim of the research is to developing and analysing the mechanical-rheological model of the material, assess the process of relative deformation of maize grain during combined grinding by impact-cutting and determining the overall mechanical work for the destruction. The object of the research are the structural-mechanical properties of a maize grain, energy intensity of the process of destruction of an individual grain under conditions of impact-cutting action. The subject of the research is the regularities of the process of deforming a grain under the action of external load of the cutting edge of the crusher’s impactor. The paper defines the values of absolute deformation and mechanical work performed during the destruction of corn grain under the action of an applied shock-cutting load. These characteristics are presented in analytical and graphic form. The results of these studies make it possible to establish the boundary values of the plastic and elastic absolute deformations occurring in the material. This is a necessary condition for further theoretical substantiation of the law of energy-saving grinding.
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Solona, Olena, et Ihor Kupchuk. « DEVELOPMENT OF A FUNCTIONAL MODEL OF A VIBRATING MILL WITH ADAPTIVE CONTROL SYSTEM OF MODE PARAMETERS ». Dans Modernization of research area : national prospects and European practices. Publishing House “Baltija Publishing”, 2022. http://dx.doi.org/10.30525/978-9934-26-221-0-12.
Texte intégralRésumé :
The research was supported and funded by the Ministry of Education and Science of Ukraine under grant No. 0121U108589 «Development of a complex of energy-efficient and resource-saving equipment and promising technologies for feeding farm animals of the AIC of Ukraine». The introduction of energy-efficient machines and technologies in the system of feed preparation and animal feeding is an important prerequisite for the development of agriculture. One of the advanced types of grinding technology are vibrating mills, which provide high specific productivity at relatively low energy consumption, adjustable tone of grinding products. Vibration impact on the product significantly increases the shock-absorbing effect with the possibility of wide and separate variation of shock and abrasion factors. Significant speed of mechanical and heat and mass transfer processes, a high degree of homogeneity of the product, the ability to effectively implement fine grinding and dispersion of the product at relatively low energy consumption lead to the widespread use of vibratory grinding.The constructive scheme of the mill is developed, in which the flat vertical vibrating field provides lifting of a part of loading and by means of the transport-reloading device carries out its continuously regulated movement from one grinding chamber to another, thereby circulating-spatial movement of the environment in which grinding shock interaction of grinding bodies and material that is crushed. One of the most important rules for the construction of vibrating mills is the need to maximize the degree of their automation in order to increase productivity, improve the quality of grinding and reduce the cost of the technological process.A constructive model of a controlled vibration mill with spatial-circulating motion was also developed, which constantly changes to the resonant mode of operation at the set technologically optimal parameters (productivity) and minimum energy consumption for vibration when changing the mass of the working body in the process of separation and unloading of crushed material from the grinding chamber.The aim of the study is to establish the dependence of the parameters of the crushed mass along the grinding chambers and in places of overload on the parameters of vibration of the vibration mill of continuous motion.Development of a structural model of adaptive vibration mill with spatial-circulating loading movement which when changing the mass of the working body in the process of separation and unloading of crushed material from the grinding chamber could constantly adapt to resonant mode at given technologically optimal parameters (productivity) and minimum energy consumptionResearch methods. Theoretical and experimental research methods were used in the work. Experiment planning and regression analysis methods were used in conducting experiments and processing experimental data. Verification of the adequacy of the obtained dependences with experimental data was carried out by methods of mathematical statistics.Scientific novelty: the theory and practice of vibration mechanics were further developed, in particular, the conditions of vertical lifting of the loading part in vibrating mills with a U-shaped chamber were determined and the influence of the main factors on the lifting height was studied; for the first time the scheme of the vibrating mill with spatial-circulating loading movement is developed, in which the effect of lifting of loading is used and by means of the transport-technological device reloading in the interconnected chambers is carried out.Practical significance. The conditions and parameters of the vibration field that regulate the intensity and duration of grinding are determined. The dependence of the productivity Q of a vibrating mill on the velocity of transporting the loaded mass along the grinding chamber has been established. The structure and two-circuit principle of control of work of adaptive vibration mill with spatial-circulating movement of loading are offered.
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Zhulay, Yuriy, Olexiy Nikolayev et Yuri Kvasha. « Estimation of the Mechanical Oscillatory Power of the Drill String for Rational Sonic Drilling ». Dans Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde221175.
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Efficiency analysis of sonic drilling of wells and the choice of rational operational modes of drill bit vibration loading to increase the rate of penetration was carried out. The rational operational modes are studied on the basis of an assessment of the power of the drilling process with a cavitation hydrovibrator. This paper presents an approach to calculating the mechanical oscillatory power of a drill bit. The approach uses a developed mathematical model of the dynamics of cavitation hydraulic vibrator with drill string. The mathematical model describes the interaction of drill string longitudinal vibrations and drill mud hydraulic oscillations at regime of the cavitation self-oscillations of the drilling fluid flow in the vibrator. The mechanical oscillatory power has been determined for the specific drill string. Rational operation modes of the cavitation hydrovibrator for efficient conversion of a stationary flow of drill fluid into drill bit mechanical oscillatory power and ensuring a high rate of penetration are evaluated.
Actes de conférences sur le sujet "VIBRATORY LOADING"
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Aziz, Imran, Wasim Tarar, Imran Akhtar et M. Nadeem Azam. « Vibratory Stress Suppression in Turbine Blades Subjected to Aerodynamic Loading ». Dans ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63724.
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Vibratory stresses are the main cause of failure in gas turbine engines and other rotating machinery components. These stresses must be attenuated to an acceptable level through an efficient process in order to prevent failures in turbine blades. Research [8] has shown that a thin magneto mechanical coating layer can make a significant contribution to the damping and reduction of these vibratory stresses. Previous studies on analyzing the damping characteristics of these coatings for various applications, such as beams and turbine blades, employed general solid mechanics loads. In this study, we numerically compute aerodynamic loads on one and a half stage axial turbine in order to bring more reality to the problem. We employ a three-dimensional finite-volume based solver to simulate the flow in the turbine using SST model to account for turbulence effects. Sliding mesh technique is used to allow the transfer of flow parameters across the sliding rotor/stator interfaces. In order to model a single passage configuration, profile transformation method is used. A free vibration analysis has been performed to obtain natural frequencies and corresponding mode shapes to analyze resonance conditions. The computed CFD loads are then applied to an uncoated and coated turbine blade through a finite-element analysis (FEA) package. A forced response analysis is performed at the critical frequencies to obtain vibratory stresses. Numerical results show suppression of vibratory stresses at various low and high frequency vibration modes. The results are benchmarked against published data and closely match the expected outcome. The research presents an effective procedure for suppression of vibratory stresses in gas turbine engine component subjected to real world aerodynamic loading. The new procedure is a significant improvement towards more realistic simulation based solutions for vibration suppression problems.
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Kim, Dennis, et Robert M'Closkey. « A MEM vibratory gyro with mode-matching achieved by resonator mass loading ». Dans 2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014. IEEE, 2014. http://dx.doi.org/10.1109/plans.2014.6851409.
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Alexander, Chris, Dave Runte et Randy Long. « Assessing the Effects of Vibratory Loading on Pipelines Using Analysis and Monitoring Techniques ». Dans ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-3077.
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This paper provides the methods and results associated with an engineering assessment for a project involving pile driving adjacent to an active 6-inch (152 mm) nominal diameter gas pipeline. The pile driving was associated with the expansion of the I-95 Highway located in Daytona Beach, Florida. The work involved analysis, metallurgical field evaluation, and measurement of strain and acceleration in the pipe during the pile driving. The analysis involved using finite element methods to predict stresses in the pipe using acceleration loads provided during a previous pile driving exercise. Using a range of soil stiffness values, the calculated bending stresses in the pipeline ranged from 50 to 2,000 psi (0.3 to 13.8 MPa). Even with the most compliant soils, the stress was relatively low compared to the hoop stress created by an internal pressure of 500 psi (3.4 MPa). The metallurgical field investigation involved careful inspection of the pipe quality, including field replication and determining the carbon content of one weld. The strain measurements indicated that the stress levels in the pipe were below design stress limits and that the short-term pile driving loads did not inflict serious injury to the line. Findings of the investigation indicated that the pipe had been well-maintained over its 40 year life and that no measurable corrosion was present. This project demonstrates the benefits derived in using a range of engineering disciplines and capabilities to ensure safety in conducting potentially-damaging activities adjacent to active gas pipelines.
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Kulkarni, Avadhoot, et Gerry LaRue. « Vibratory Response Characterization of a Radial Turbine Wheel for Automotive Turbocharger Application ». Dans ASME Turbo Expo 2008 : Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-51355.
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One of the major challenges in the design and development of a turbine wheel for automotive turbochargers is high cycle fatigue (HCF) due to blade resonant vibrations. This is a result of the design trend towards higher blade loading, thinner blades and higher tip speeds which has led to wheel designs and manufacturing techniques which further accentuate the HCF risk. This paper is directed at investigating the resonant response of a variable geometry radial turbine wheel. Wheel resonant response due to vane count excitation was captured by measuring blade tip timing using the Non-intrusive Stress Measurement System (NSMS). Blade deflections in second mode were measured at various turbine inlet pressures and at various inlet vane openings to study their sensitivity. Time dependent 3D CFD calculations were performed to accurately predict the flow field and hence the blade loading at various operating conditions. A finite element (FE) model of the wheel was created in ANSYS and blade loadings calculated from CFD were transferred to the FE mesh to predict blade vibratory strains. Trends of predicted strains were successfully compared against the blade deflection measurements at different turbine inlet pressures and at different vane openings.
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Ernst, Matthew, Cholmin Choi et Abhijit Dasgupta. « Computational Strategies to Minimize Transient Response During Time-Domain Analysis of Structures Under Vibratory Loading ». Dans ASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ipack2013-73200.
Texte intégralRésumé :
Time-domain dynamic analysis of vibratory systems becomes useful in finite element analysis (FEA) when the structure’s response can no longer be assumed linear, as frequency-domain (spectral superposition) methods require. Time-domain analysis also permits the use of cycle-counting methods when assessing the vibration durability of electronic assemblies. The analyst is often limited to simulating only the first few cycles of the vibration response in very complex models, to minimize the computational burden. However, the accuracy of time domain analysis can be questionable during these first few cycles, due to unwanted transients, unless the initial conditions are properly modeled to correctly produce the steady state response. This paper explores this sensitivity to initial conditions for undamped and damped structures. Strategies for calculating and implementing proper initial conditions within FEA are discussed. Two illustrative examples are presented for simplicity. The first consists of a simple cantilever beam so that the numerical results can be compared to known analytic solutions and the basic theory can be demonstrated. The second example is a 2D representation of a circuit card assembly containing multiple leadless chip resistor components, so that implementation details can be demonstrated for more complex structures. This paper is intended to have tutorial value to FEA users who have to conduct time-domain dynamic analysis.
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McGinty, Robert, John Vine, Dan Liebschutz, Philip Conjelko et Jeffery Brenna. « MH-60 Full Scale Test Rig Loads Development and Analysis ». Dans Vertical Flight Society 76th Annual Forum & Technology Display. The Vertical Flight Society, 2020. http://dx.doi.org/10.4050/f-0076-2020-16368.
Texte intégralRésumé :
Mercer Engineering Research Center (MERC) is supporting Naval Air Systems Command (NAVAIR) in the determination of external airframe loading requirements and test rig design support for an MH-60 full scale fatigue test demonstrator project being conducted in collaboration with the Australian Defence Science and Technology Group (DST Group). The analyses included determination of loads for quasistatic and vibratory flight conditions, sensitivity of the structural response to the loads, displacements at actuators across the MH-60R usage spectrum, and feasibility of driving aircraft vibrations at frequencies lower than those measured in flight - specifically, obtaining vibration levels measured at 17.2 Hz by imposing forces at only 2.15 Hz. The studies also addressed the minimum number and locations of actuators required for static and vibratory loading.
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Healy, Richard, et Farhan Gandhi. « A Computational Investigation of Canted Side-by-side Rotors In Ground Effect ». Dans Vertical Flight Society 79th Annual Forum & Technology Display. The Vertical Flight Society, 2023. http://dx.doi.org/10.4050/f-0079-2023-17990.
Texte intégralRésumé :
This study investigates the interactional aerodynamics of canted side-by-side rotors hovering in ground effect. The 5.5 ft diameter 3-bladed fixed-pitched rotors are simulated using CFD at a targeted 5 psf disk loading. Simulations are performed using the commercial Navier Stokes solver AcuSolve with a delayed detached eddy simulation (DDES) model. Side-by-side rotors are simulated at a height above the ground equal to one rotor radius (z/R = 1.0) and with 2.5R hub-hub spacing. In addition to an uncanted case, side-by-side rotors are simulated in ground effect (IGE) with 10° differential lateral cant, 10° inwards cant, and 10° outwards cant. Between the uncanted side-by-side rotors IGE, a highly turbulent mixing region is identified where the wakes of each rotor collide and fountain up. As blades traverse the highly turbulent flow, strong vibratory loading is induced and a thrust loss is observed over the outboard blade sections. The associated unsteady vertical loading for uncanted, laterally canted, and canted outwards rotors is similar, ranging from 10% - 16% peak-to-peak whereas canted inwards rotors show increased vibratory loading at 22% peak-to-peak. Integrated thrust for uncanted rotors IGE is 4.3% more than if out of ground effect (OGE), though when laterally canted or canted outwards, thrust generation is reduced to within 1% of isolated OGE rotors. Canted inwards rotors produce even less thrust, generating 15.2% less thrust than isolated OGE rotors. Overall, canting side-by-side rotors IGE incurs thrust production and vibration penalties. If canting is required for improved control authority, laterally canted rotors generate the most thrust while canted outwards rotors generate the least vibratory loading.
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Shen, M. H. Herman, et Theodore Nicholas. « Reliability High Cycle Fatigue Design of Gas Turbine Blading System Using Probabilistic Goodman Diagram ». Dans ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2652.
Texte intégralRésumé :
Abstract A framework for the probabilistic analysis of high cycle fatigue is developed. The framework will be useful to U.S. Air Force and aeroengine manufacturers in the design of high cycle fatigue in disk or compressor components fabricated from Ti-6Al-4V under a range of loading conditions that might be encountered during service. The main idea of the framework is to characterize vibratory stresses from random input variables (uncertainties such as initial crack size, crack location, loading, material properties, and manufacturing variability). The characteristics of such vibratory stresses will be portrayed graphically as histograms, or probability density function (PDF). The outcome of the probability measures associated with all the values of a random variable exceeding the material capability is achieved by a failure function g(X) defined by the difference between the vibratory stress and Goodman line or surface such that the probability of HCF failure is P(f) = P(g(X<0)). The framework can be used to facilitate the development design tools for the prediction of inspection schedules and reliability in aeroengine components. Such tools could lead ultimately to improved life extension schemes in aging aircraft, and more reliable methods for the design and inspection of critical components.
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Gordon, Ali P., et Thomas Bouchenot. « A Reduced Order Constitutive Modeling Approach for a Material Subjected to Combined Cycle Fatigue ». Dans ASME Turbo Expo 2018 : Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-76903.
Texte intégralRésumé :
Material selection for key components is a critical step in the design process where high temperature and large loads are involved. Service conditions, however, may be more aggressive than those to which many materials have been exposed to in laboratory conditions. For example, key combustion equipment will experience super-imposed thermal, mechanical, and vibratory loading. Despite the more recent efforts to characterize materials under these so-called combined extreme environments (CEEs), the temperature- and rate-dependent cyclic hardening/softening responses are still relatively under-characterized. A method to develop first approximations of constitutive model/parameters for materials under extreme service conditions is presented. The method is exercised on IN617 a Ni-base alloy often employed for high temperature applications. The approach shows that a minimal collection of tensile, creep, and LCF data are needed to develop predictions of materials under thermomechanical fatigue with vibratory loading.
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Lee, Seung Jae, Han C. Yu, Sungeun Peter Kim, Mun-Keun Ha, Gun-Il Park, Jae-Woong Choi, Munsung Kim et James S. C. Tai. « Analysis of Full-Scale Hull Girder Loads of a Container Carrier and Its Simulation Using a Nonlinear Seakeeping Program ». Dans ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20661.
Texte intégralRésumé :
ABS, SHI, and OOCL have been conducting a project on full-scale measurement of hull stress of a container carrier since 2006. A Hull Stress Monitoring System (HSMS) was installed on an 8063 TEU container carrier recording hull girder loads and other navigation data. Vibratory responses of the hull girder were recorded at certain conditions, such as in the limited fetch storm waves in the Mediterranean Sea. The recorded data has been analyzed to determine the level of vibratory responses and the conditions in which they occurred. Since the vibratory response is superposed to the wave frequency component of the hull girder loads, it also affects the statistics of the maximum hull girder loads in waves. The effects of the vibratory responses in the long-term have been investigated for the dynamic Vertical Bending Moment (VBM) and bow acceleration. While the full-scale measurement provides valuable data for what actually happened in real vessel operations, the actual conditions can not be controlled, such as the wave environments or loading conditions. Hence, numerical calculation results are also desirable to investigate the vibratory responses under controlled conditions taking into account the elastic hull girder properties under exact conditions for validation purposes. ABS has been applying a time domain nonlinear wave/body interaction analysis program, NLOAD3D, for the assessment of the structural responses of vessels in large waves. The NLOAD3D program has been further developed to incorporate an elastic beam model to reproduce vibratory hull girder responses, with the simulations being carried out on motions and moments for selected notable events recorded during the voyages. Comparisons of the simulation and the measurement are presented.
Rapports d'organisations sur le sujet "VIBRATORY LOADING"
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Feng, Zhicao. PR-218-174512-R01 Full-Scale Surface Loading Testing of Buried Pipes. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), juin 2021. http://dx.doi.org/10.55274/r0012107.
Texte intégralRésumé :
In 2015, Kiefner and Associates, Inc. (Kiefner) completed the ENV-6-1 project "Field Validation of Surface Loading Stress Calculations for Buried Pipelines" in which Kiefner monitored three buried pipe test segments at the Berne Station in Ohio to measure circumferential and longitudinal stresses due to heavy equipment crossing over the segments. This ENV-6-2 study "Full-Scale Surface Loading Testing of Buried Pipes Vibratory Compactor and Temporary Crossing" ionducted in the same location and on the same three pipeline specimens. The objective of this project is to develop surface loading criteria for pipelines with shallow burial depth under temporary crossings (e.g. mat, bridge, or steel plate) and pipeline subjected to dynamic loading from a vibrator compactor.
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R.C. Quittmeyer. Mechanical Assessment of the Drip Shield to Vibratory Motion and Dynamic and Static Rock Loading. Office of Scientific and Technical Information (OSTI), août 2005. http://dx.doi.org/10.2172/893882.
Texte intégral
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R.C. Quittmeyer. Mechanical Assessment of the Drep Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading. Office of Scientific and Technical Information (OSTI), novembre 2005. http://dx.doi.org/10.2172/893886.
Texte intégral
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Zand, Benjamin. PR-218-104509-R02 Field Validation of Surface Loading Stress Calculations for Buried Pipelines Milestone 2. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), avril 2019. http://dx.doi.org/10.55274/r0011477.
Texte intégralRésumé :
In this work, the Canadian Energy Pipeline Association (CEPA) equation for prediction of hoop stress in a buried pipeline was validated using the Milestone 1 experimental data. The Milestone 1 testing program included a 24-inch outside diameter (OD), 0.25-inch wall thickness (WT) pipe specimen in sand (24-inch Sand); a 12.75-inch OD, 0.5-inch WT pipe specimen in clay (12-inch Packed Clay); and a 24-inch OD, 0.25-inch WT pipe specimen in clay (24-inch Dumped Clay). Two different depths of cover (DOC) values of 2 and 3 feet were used in the testing and the test specimens were crossed by a variety of construction equipment, namely a dump truck, a bulldozer, a front loader, and a vibratory compactor. The testing was conducted at internal pipe pressures of zero, 550 and 750 psig.