The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Jamie E Padgett - One of the best experts on this subject based on the ideXlab platform.
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Stiffening Ring design for prevention of storm surge buckling in aboveground storage tanks
Journal of Structural Engineering-asce, 2019Co-Authors: Sabarethinam Kameshwar, Jamie E PadgettAbstract:AbstractThis paper proposes the use of an additional Stiffening Ring to prevent buckling of aboveground storage tanks (ASTs) under storm-surge inundation and presents an approach to obtain an optim...
Jian-guo Nie - One of the best experts on this subject based on the ideXlab platform.
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Research and optimization on laminated steel tube column-concrete beam joints with outer Stiffening Ring
Science China-technological Sciences, 2013Co-Authors: Jian-guo Nie, Yu-hang Wang, Mu-xuan TaoAbstract:In practical design, the joints with outer Stiffening Ring were used to connect concrete beams and laminated steel tube columns. The seismic behavior of joints with outer Stiffening Ring with various types was studied based on experiments. The beaRing capacity, rigidity, ductility, energy dissipation capacity, deformation property and strain distribution of the joints with outer Stiffening Ring with various types were comprehensively evaluated based on the test results of three specimens under quasi-static cyclic loading and finite element analysis. The test results showed that the failure mode, hysteretic behavior, beaRing capacity and rigidity degradation of the joints with outer Stiffening Ring with various types were nearly identical. Furthermore, the strain distribution of the outer Stiffening Ring of the three joints was nearly the same. The detailing recommendation for the outer strengthening Rings was proposed for the concrete beam-laminated steel tube column joints with outer Stiffening Ring, in order to ensure the good seismic capacity of the joints.
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New Connection System for Confined Concrete Columns and Beams. I: Experimental Study
Journal of Structural Engineering-asce, 2008Co-Authors: Jian-guo Nie, Yu Bai, C.s. CaiAbstract:A new connection system for a concrete filled steel tube composite column and reinforced concrete beams is proposed. In this connection, the steel tube is interrupted while the reinforced concrete beams are continuous in the joint zone. Multiple lateral hoops that constitute the Stiffening Ring are used to confine the core concrete in the connection zone. The transfer of moment at the beam ends can be ensured by continuous rebars; the weakening of the axial load beaRing capacity due to the interruption of the steel tube can be compensated by the confinement of the Stiffening Ring. Using these configurations, concrete casting and tube lifting can be made more convenient since welding and hole drilling in situ can be avoided. Axial compression experiments on six specimens and reversed cyclic loading tests on three interior column specimens and three corner column specimens were conducted to evaluate this new beam-column system; load-deflection performance, typical failure modes, stress and strain distributions, and the energy dissipation capacity were obtained. The experimental results showed that the effective confinement can be achieved by the Stiffening Ring, and an excellent axial beaRing capacity can be obtained, as well as a superior ductility and energy dissipation capacity. As a new connection system for the concrete filled steel tube composite column with reinforced concrete beams, it can also be applied to other types of confined concrete columns.
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New Connection System for Confined Concrete Columns and Beams. II: Theoretical Modeling
Journal of Structural Engineering-asce, 2008Co-Authors: Yu Bai, Jian-guo Nie, C.s. CaiAbstract:The concept of confined concrete has been widely accepted throughout the structural engineeRing field, such as the spiral, steel tube, or carbon fiber composite shell confined concrete, etc. In the present study, this concept has not only been used in the structural columns, but also in joints. In this connection system, the steel tube is interrupted at the floor, the concrete in the connection zone is confined by a Stiffening Ring with multiple lateral hoops, and the reinforced concrete beams are continuously arranged through the joint. The structural behavior of this new connection system in axial compression tests and reversed cyclic loading tests is presented in a companion paper. In the present study, the beaRing strength of composite columns and the joint in axial compression is obtained based on the stress and strain analyses. The critical volume fraction of transverse stirrups of the composite column and the effective confining radius in the Stiffening Ring are proposed based on the thick cylinder model with the assumption of plane stress state. By using these solutions, it is favorable to obtain the stress distribution in confining concrete and the beaRing strength of the confined concrete. For the reversed cyclic loading tests, the Clough hysteresis model is used to simulate the hysteresis loops of the specimens without consideRing the stiffness degradation in the unloading process. The results of the theoretical modeling are generally in good agreement with the experimental observations.
Sabarethinam Kameshwar - One of the best experts on this subject based on the ideXlab platform.
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Stiffening Ring design for prevention of storm surge buckling in aboveground storage tanks
Journal of Structural Engineering-asce, 2019Co-Authors: Sabarethinam Kameshwar, Jamie E PadgettAbstract:AbstractThis paper proposes the use of an additional Stiffening Ring to prevent buckling of aboveground storage tanks (ASTs) under storm-surge inundation and presents an approach to obtain an optim...
Marek J Glogowski - One of the best experts on this subject based on the ideXlab platform.
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additives contents in pag and synthetic motor base oils and their effect on electrostatic phenomena in a rotating shaft oil lip seal system
IEEE Transactions on Dielectrics and Electrical Insulation, 2013Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on the electrostatic aspects of anti-wear (AW) and friction modifier (FM) additives (agents) when these are added to PAG (polyalkylene glycol) and PAO 6 (synthetic) motor base oils to obtain their blends. Experiments are carried out in a rotating shaft-oil-lip seal system (a friction junction) which is a specially built experimental facility to be the simplified model of an engine crankcase in the interior of which an earthed metal shaft rotates at given angular velocities from 500 up to 1000 rpm. The AW and FM additives contents in blends are 0.1 and 0.5 wt%. Oil temperature is controlled electronically and changed from 60 up to 110°C. An 88-mm diameter lip seal is used in the experiments. Electric potential of a Stiffening Ring of the lip seal tested is measured directly with an electrometer. The experimental results are the relationships of the potential induced in a Stiffening Ring to shaft's angular velocity and to the temperature of pure base oils and their blends with AW and FM agents.
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anti wear additive content in fully synthetic pao and pag base oils and its effect on electrostatic and tribological phenomena in a rotating shaft oil lip seal system
Journal of Physics: Conference Series, 2013Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on electrostatic and tribological aspects of different anti-wear additive's contents when an additive is blended with different fully synthetic (poly-α-olefin) and PAG (polyalkylene glycol) base oils in a rotating shaft–oil and oil–lip seal interfacial system. The experimental results are the relationships of electric potential induced in a lip seal's Stiffening Ring to angular velocity of a rotating metal shaft and to temperature of the oils tested. The braking torque of a shaft is measured with a torquemeter sensor connected directly with a microprocessor-based system for controlling the rotational speed and for measuRing the shaft's braking torque and oil temperature. The beneficial and promising results are obtained for PAG when an external DC electric field is applied to the system and the braking torque is then reduced for a certain combination of the base oil and additive's contents. On the basis of the former and present research results an analysis is made to permit one to show how the type of the oils and additives tested can affect both interfaces: rotating shaft–oil and oil–lip of the lip seal and especially the braking torque.
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tribocharging in a rotating shaft oil lip seal system for different engine base oils additive and their blends
Journal of Electrostatics, 2009Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:Abstract The paper presents the results of experiments on tribocharging of different mineral, semisynthetic, and synthetic base oils and their blends with additives. An antiwear additive ZDDP (zinc dialkyldithiophosphate) is tested when added to base oils in different percentages by weight. Experiments are carried out on the specially built experimental facility to be a simplified model of an engine crankcase in whose interior an earthed metal shaft rotates at given angular velocities. The potential of a Stiffening Ring of a lip seal is measured directly with an electrometer. The potential is a measure of tribocharging in a rotating shaft–oil–lip seal system, friction junction, and especially between both interfaces: shaft surface–oil and oil–lip of a lip seal. The experimental results are presented in the form of some characteristics that are relationships of the potential induced in the Stiffening Ring with oil's temperature for different angular shaft's velocities and additives, contents. The oil's temperature ranges from 60 to 110 °C and is controlled automatically. The angular velocities of a shaft used are 500 and 1500 rpm. The additive contents in the blends with different base oils are 0.1 and 0.2%. The pure base oils of all the types and some lip seals are also examined. Moreover, the influence of an external DC electric field applied between the earthed shaft and the Stiffening Ring on the braking torque of the shaft is examined for a range of temperatures of the pure oils and their blends with the additive used, angular velocities, and additive contents. The electric field is produced while applying the high DC voltage of both polarities between the shaft and the Ring. The absolute value of the voltage is in a range from 500 to 1500 V.
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Effects of engine base oil type and ZDDP on the electrical double layer in the rotating shaft-oil-lip seal system with and without an external DC electric field
2008 IEEE International Conference on Dielectric Liquids ICDL 2008, 2008Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on tribo-charging of\na blend of mineral base oil and different zinc dialkylditophosphate\n(ZDDP) contents. Experiments were carried out on the specially built\nexperimental facility to be a simplified model of an engine crankcase\nin whose interior an earthed metal shaft rotated at given angular\nvelocities. The potential of a Stiffening Ring of a lip seal was\nmeasured directly with an electrometer. The experimental results\nare presented in the form of some characteristics that are relationships\nof the potential induced on the Stiffening Ring to the oil temperature\nfor different angular shaft velocities and the ZDDP contents. Also\nthe effects of an external DC electric field on the braking torque\nof the steel shaft were examined for a range of oil temperatures,\nangular velocities, and ZDDP contents. An analysis of the research\nresults obtained permitted one to show how the ZDDP content in a\nblend with the base oil tested, angular velocity, and oil temperature\ncould affect charging in the interface system: rotating shaft-oil\nand oil-lip seal, as well as the whole oil film in between and both\nelectrical double layers (EDL) at the surfaces of the shaft and of\nthe lip of a lip seal.
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tribocharging in a rotating shaft oil seal system and the effect of an external electric field
Journal of Electrostatics, 2005Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:Abstract The results are shown of tests on the effect of an auxiliary external DC electric field on the braking torque of a rotating shaft. Experiments were carried out on a simplified model of an engine in whose interior a metal shaft rotated with given angular velocities. The shaft was lubricated with different oils producing an oil film between the shaft's surface and a lip seal. The influence of different oil temperatures on the braking torque was also examined. The results are presented here for fresh Polish oil LOTOS 15W40 and a lip seal diameter of 88 mm. An increase in the negative DC voltage applied between the shaft and Stiffening Ring of the lip seal caused a reduction in braking torque.
Juliusz B Gajewski - One of the best experts on this subject based on the ideXlab platform.
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additives contents in pag and synthetic motor base oils and their effect on electrostatic phenomena in a rotating shaft oil lip seal system
IEEE Transactions on Dielectrics and Electrical Insulation, 2013Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on the electrostatic aspects of anti-wear (AW) and friction modifier (FM) additives (agents) when these are added to PAG (polyalkylene glycol) and PAO 6 (synthetic) motor base oils to obtain their blends. Experiments are carried out in a rotating shaft-oil-lip seal system (a friction junction) which is a specially built experimental facility to be the simplified model of an engine crankcase in the interior of which an earthed metal shaft rotates at given angular velocities from 500 up to 1000 rpm. The AW and FM additives contents in blends are 0.1 and 0.5 wt%. Oil temperature is controlled electronically and changed from 60 up to 110°C. An 88-mm diameter lip seal is used in the experiments. Electric potential of a Stiffening Ring of the lip seal tested is measured directly with an electrometer. The experimental results are the relationships of the potential induced in a Stiffening Ring to shaft's angular velocity and to the temperature of pure base oils and their blends with AW and FM agents.
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anti wear additive content in fully synthetic pao and pag base oils and its effect on electrostatic and tribological phenomena in a rotating shaft oil lip seal system
Journal of Physics: Conference Series, 2013Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on electrostatic and tribological aspects of different anti-wear additive's contents when an additive is blended with different fully synthetic (poly-α-olefin) and PAG (polyalkylene glycol) base oils in a rotating shaft–oil and oil–lip seal interfacial system. The experimental results are the relationships of electric potential induced in a lip seal's Stiffening Ring to angular velocity of a rotating metal shaft and to temperature of the oils tested. The braking torque of a shaft is measured with a torquemeter sensor connected directly with a microprocessor-based system for controlling the rotational speed and for measuRing the shaft's braking torque and oil temperature. The beneficial and promising results are obtained for PAG when an external DC electric field is applied to the system and the braking torque is then reduced for a certain combination of the base oil and additive's contents. On the basis of the former and present research results an analysis is made to permit one to show how the type of the oils and additives tested can affect both interfaces: rotating shaft–oil and oil–lip of the lip seal and especially the braking torque.
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Base Oil and Its Blends with ZDDP and Their Effect on Tribocharging, Braking Torque and Electrical Double Layers in a Friction Junction
Tribology Letters, 2010Co-Authors: Juliusz B Gajewski, Marek J. GłogowskiAbstract:The paper presents the results of experiments on tribocharging of a blend of mineral-base oil and different zinc dialkyldithiophosphate (ZDDP) contents in a friction junction. A friction junction is constituted by a rotating shaft, a film of pure base oil, or its blend with the ZDDP, and a rotary lip seal, which is the interfacial system as a whole. Experiments were carried out on the specially built experimental facility to be a simplified model of an engine’s crankcase (or sump) in whose interior an earthed metal shaft rotated at given angular velocities. Electric potential of a Stiffening Ring of a lip seal, which is a measure of tribocharging, was measured directly with an electrometer. The Stiffening Ring’s potential is induced by charge in the film of pure base oil or the ZDDP-oil blend and is a function of the oil temperature for different angular shaft velocities and the ZDDP contents. The potential is presented in the form of some characteristics. Also the effects of an external DC electric field on the braking torque of the rotating steel shaft were examined for a range of oil temperatures, angular velocities, and ZDDP contents, and here the torque is presented for one temperature and different DC voltages of both polarities. An analysis of the research results obtained permitted us to show how the ZDDP content in a blend with the base oil tested, angular velocity, and oil temperature could affect tribocharging in the interfacial systems: the rotating shaft-oil and oil-lip seal, as well as the whole oil film in between and both electrical double layers (EDLs) at the surfaces of a shaft and of a lip of a rotary lip seal in the friction junction.
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tribocharging in a rotating shaft oil lip seal system for different engine base oils additive and their blends
Journal of Electrostatics, 2009Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:Abstract The paper presents the results of experiments on tribocharging of different mineral, semisynthetic, and synthetic base oils and their blends with additives. An antiwear additive ZDDP (zinc dialkyldithiophosphate) is tested when added to base oils in different percentages by weight. Experiments are carried out on the specially built experimental facility to be a simplified model of an engine crankcase in whose interior an earthed metal shaft rotates at given angular velocities. The potential of a Stiffening Ring of a lip seal is measured directly with an electrometer. The potential is a measure of tribocharging in a rotating shaft–oil–lip seal system, friction junction, and especially between both interfaces: shaft surface–oil and oil–lip of a lip seal. The experimental results are presented in the form of some characteristics that are relationships of the potential induced in the Stiffening Ring with oil's temperature for different angular shaft's velocities and additives, contents. The oil's temperature ranges from 60 to 110 °C and is controlled automatically. The angular velocities of a shaft used are 500 and 1500 rpm. The additive contents in the blends with different base oils are 0.1 and 0.2%. The pure base oils of all the types and some lip seals are also examined. Moreover, the influence of an external DC electric field applied between the earthed shaft and the Stiffening Ring on the braking torque of the shaft is examined for a range of temperatures of the pure oils and their blends with the additive used, angular velocities, and additive contents. The electric field is produced while applying the high DC voltage of both polarities between the shaft and the Ring. The absolute value of the voltage is in a range from 500 to 1500 V.
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Effects of engine base oil type and ZDDP on the electrical double layer in the rotating shaft-oil-lip seal system with and without an external DC electric field
2008 IEEE International Conference on Dielectric Liquids ICDL 2008, 2008Co-Authors: Juliusz B Gajewski, Marek J GlogowskiAbstract:The paper presents the results of experiments on tribo-charging of\na blend of mineral base oil and different zinc dialkylditophosphate\n(ZDDP) contents. Experiments were carried out on the specially built\nexperimental facility to be a simplified model of an engine crankcase\nin whose interior an earthed metal shaft rotated at given angular\nvelocities. The potential of a Stiffening Ring of a lip seal was\nmeasured directly with an electrometer. The experimental results\nare presented in the form of some characteristics that are relationships\nof the potential induced on the Stiffening Ring to the oil temperature\nfor different angular shaft velocities and the ZDDP contents. Also\nthe effects of an external DC electric field on the braking torque\nof the steel shaft were examined for a range of oil temperatures,\nangular velocities, and ZDDP contents. An analysis of the research\nresults obtained permitted one to show how the ZDDP content in a\nblend with the base oil tested, angular velocity, and oil temperature\ncould affect charging in the interface system: rotating shaft-oil\nand oil-lip seal, as well as the whole oil film in between and both\nelectrical double layers (EDL) at the surfaces of the shaft and of\nthe lip of a lip seal.
