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Novel System Architectures by Individual DrivesWeber, Jürgen, Beck, Benjamin, Fischer, Eric, Ivantysyn, Roman, Kolks, Giacomo, Kunkis, Markus, Lohse, Harald, Lübbert, Jan, Michel, Sebastian, Schneider, Markus, Shabi, Linart, Sitte, André, Weber, Juliane, Willkomm, Johannes 02 May 2016 (has links) (PDF)
Measures of individualization and integration offer a great potential for further development and optimization in hydraulic drive technology. Advantages are seen especially for energy efficiency and functionality. These potentials motivate current research activities for displacement controlled systems and for valve controlled structures. For the latter, the focus lies on strategies of independent metering. Furthermore, expected challenges for the future are discussed.
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Toward Supervisory-Level Control for the Energy Consumption and Performance Optimization of Displacement-Controlled Hydraulic Hybrid MachinesBusquets, Enrique, Ivantysynova, Monika 03 May 2016 (has links) (PDF)
Environmental awareness, production costs and operating expenses have provided a large incentive for the investigation of novel and more efficient fluid power technologies for decades. In the earth-moving sector, hydraulic hybrids have emerged as a highly efficient and affordable choice for the next generation hydraulic systems. Displacementcontrolled (DC) actuation has demonstrated that, when coupled with hydraulic hybrids, the engine power can be downsized by up to 50% leading to substantial savings. This concept has been realized by the authors‘ group on an excavator prototype where a secondary-controlled hydraulic hybrid drive was implemented on the swing. Actuatorlevel controls have been formulated by the authors‘ group but the challenge remains to effectively manage the system on the supervisory-level. In this paper, a power management controller is proposed to minimize fuel consumption while taking into account performance. The algorithm, a feedforward and cost-function combination considers operator commands, the DC actuators‘ power consumption and the power available from the engine and hydraulic hybrid as metrics. The developed strategy brings the technology closer to the predicted savings while achieving superior operability.
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Generator Speed Control Utilizing Hydraulic Displacement Units in a Constant Pressure Grid for Mobile Electrical SystemsDötschel, Thomas, Deeken, Michael, Schneider, Klaus 03 May 2016 (has links) (PDF)
Liebherr mobile harbor cranes use electrical generators to provide electrical power for load attachment devices such as container spreaders or magnets. Upcoming exhaust and noise emission standards and energy saving considerations lead to a broad diesel engine speed range. The challenging design aspect is to ensure a constant speed of the asynchronous generator by the hydraulic drive system. In addition, electrical load profiles of inductive consumers usually have DT1 system characteristics with very small time constants. They evoke fast torque variations interfacing the hydraulic transmission. Liebherr mobile harbor cranes, see Figure 1, usually have a closed hydraulic circuit containing a hydraulic pump with a high displacement volume that is adjusted electronically in accordance to the current diesel engine speed. Regarding the energy saving aspects, a further minimization of the diesel engine speed leads to a larger pump size with increasing torque losses. Depending on the pressure setting, the volume flows can be reduced in constant pressure grids. Especially in part-load operation this results in better efficiency compared to closed hydraulic circuits by minimizing the displacement volume of hydraulic components. To obtain a stable generator speed, it is essential to adjust the displacement volume of the hydraulic unit for equalizing its input torque with the Figure 1: LHM 800 Group 10 - Mobile Hydraulics | Paper 10-5 199 generator load torque. In interaction with the software-based control architecture, the stability of the electrical frequency depends on the mass inertia of the generator drive and time constants of the embedded hydraulic actuators. The system model, represented by ODEs is established and verified with a hydraulic simulation software. On that basis, the design approach of a PI-state-controller is presented. Corresponding controller gains and state feedback parameters are determined by pole placement techniques. To conclude this investigation a comparison between the hydraulically closed circuit and the constant pressure grid is shown by simulation and measurement data.
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格子等価連続体化法による鉄筋コンクリート部材の有限要素解析伊藤, 睦, ITOH, Atsushi, PHAMAVANH, Kongkeo, 中村, 光, NAKAMURA, Hikaru, 田辺, 忠顕, TANABE, Tada-aki 08 1900 (has links)
No description available.
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Non-linear finite element analysis of reinforced concrete panels and infilled frames under monotonic and cyclic loading : structures under plane stress loading are analysed up to and beyond the peak load : non-linear material properties including cracking, crushing and the non-linear behaviour at the interface of members are consideredNaji, Jamal Hadi January 1989 (has links)
A non-linear finite element program to simulate the behaviour of infilled frames and plane stress reinforced concrete members under the action of monotonic and cyclic loading has been developed. Steel is modelled as a strain hardening plastic material, and in the concrete model cracking, yielding and crushing are considered. The separation, sliding, and opening and closing of initial gaps at the interfaces between the frame and the infill panels are accounted for by adjusting the properties of interface elements. The non-linear equations of equilibrium are solved using an incremental-iterative technique performed under load or displacement control. The iterative techniques use the standard and modified Newton-Raphson method or the secant Newton method. An automatic load incrementation scheme, line searches, and restart facilities are included. The capabilities of the program have been examined and demonstrated by analysing five reinforced concrete panels, a deep beam, a shear wall, and eight infilled frames. The accuracy of the analytical results was assessed by comparing them with the experimental results and those obtained analytically by other workers and shown to be good. A study of the effects of some material and numerical parameters on the results of analyses of reinforced concrete deep beam has been carried out. Two techniques have been proposed and used to overcome numerical problems associated with local strain concentrations which occur with the displacement control, when path dependent incremental iterative procedures are used for inelastic materials. The displacement control provided with these modifications has been shown to be more efficient than the load control.
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Novel System Architectures by Individual DrivesWeber, Jürgen, Beck, Benjamin, Fischer, Eric, Ivantysyn, Roman, Kolks, Giacomo, Kunkis, Markus, Lohse, Harald, Lübbert, Jan, Michel, Sebastian, Schneider, Markus, Shabi, Linart, Sitte, André, Weber, Juliane, Willkomm, Johannes January 2016 (has links)
Measures of individualization and integration offer a great potential for further development and optimization in hydraulic drive technology. Advantages are seen especially for energy efficiency and functionality. These potentials motivate current research activities for displacement controlled systems and for valve controlled structures. For the latter, the focus lies on strategies of independent metering. Furthermore, expected challenges for the future are discussed.
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The control of an open-circuit, floating cup variable displacement pumpAchten, Peter, Eggenkamp, Sjoerd January 2016 (has links)
The floating cup principle is a general hydrostatic principle for both constant and variable displacement pumps and motors, as well as for hydraulic transformers. In this paper, the focus will be entirely on the control of the displacement of the variable 28 cc Floating Cup pump (FCVP28). The floating cup principle features two opposed swash plates, for which both angular positions need to be controlled in order to cover the entire range from zero to full displacement. The results of both extended numerical analysis as well as simplified linearized models will be compared to test results on a 28 cc FCVP. Special emphasis will be on the dynamic behaviour of the displacement control.
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Toward Supervisory-Level Control for the Energy Consumption and Performance Optimization of Displacement-Controlled Hydraulic Hybrid MachinesBusquets, Enrique, Ivantysynova, Monika January 2016 (has links)
Environmental awareness, production costs and operating expenses have provided a large incentive for the investigation of novel and more efficient fluid power technologies for decades. In the earth-moving sector, hydraulic hybrids have emerged as a highly efficient and affordable choice for the next generation hydraulic systems. Displacementcontrolled (DC) actuation has demonstrated that, when coupled with hydraulic hybrids, the engine power can be downsized by up to 50% leading to substantial savings. This concept has been realized by the authors‘ group on an excavator prototype where a secondary-controlled hydraulic hybrid drive was implemented on the swing. Actuatorlevel controls have been formulated by the authors‘ group but the challenge remains to effectively manage the system on the supervisory-level. In this paper, a power management controller is proposed to minimize fuel consumption while taking into account performance. The algorithm, a feedforward and cost-function combination considers operator commands, the DC actuators‘ power consumption and the power available from the engine and hydraulic hybrid as metrics. The developed strategy brings the technology closer to the predicted savings while achieving superior operability.
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Generator Speed Control Utilizing Hydraulic Displacement Units in a Constant Pressure Grid for Mobile Electrical SystemsDötschel, Thomas, Deeken, Michael, Schneider, Klaus January 2016 (has links)
Liebherr mobile harbor cranes use electrical generators to provide electrical power for load attachment devices such as container spreaders or magnets. Upcoming exhaust and noise emission standards and energy saving considerations lead to a broad diesel engine speed range. The challenging design aspect is to ensure a constant speed of the asynchronous generator by the hydraulic drive system. In addition, electrical load profiles of inductive consumers usually have DT1 system characteristics with very small time constants. They evoke fast torque variations interfacing the hydraulic transmission. Liebherr mobile harbor cranes, see Figure 1, usually have a closed hydraulic circuit containing a hydraulic pump with a high displacement volume that is adjusted electronically in accordance to the current diesel engine speed. Regarding the energy saving aspects, a further minimization of the diesel engine speed leads to a larger pump size with increasing torque losses. Depending on the pressure setting, the volume flows can be reduced in constant pressure grids. Especially in part-load operation this results in better efficiency compared to closed hydraulic circuits by minimizing the displacement volume of hydraulic components. To obtain a stable generator speed, it is essential to adjust the displacement volume of the hydraulic unit for equalizing its input torque with the Figure 1: LHM 800 Group 10 - Mobile Hydraulics | Paper 10-5 199 generator load torque. In interaction with the software-based control architecture, the stability of the electrical frequency depends on the mass inertia of the generator drive and time constants of the embedded hydraulic actuators. The system model, represented by ODEs is established and verified with a hydraulic simulation software. On that basis, the design approach of a PI-state-controller is presented. Corresponding controller gains and state feedback parameters are determined by pole placement techniques. To conclude this investigation a comparison between the hydraulically closed circuit and the constant pressure grid is shown by simulation and measurement data.
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Non-linear finite element analysis of reinforced concrete panels and infilled frames under monotonic and cyclic loading. Structures under plane stress loading are analysed up to and beyond the peak load. Non-linear material properties including cracking, crushing and the non-linear behaviour at the interface of members are considered.Naji, Jamal Hadi January 1989 (has links)
A non-linear finite element program to simulate the behaviour of
infilled frames and plane stress reinforced concrete members under
the action of monotonic and cyclic loading has been developed. Steel
is modelled as a strain hardening plastic material, and in the
concrete model cracking, yielding and crushing are considered. The
separation, sliding, and opening and closing of initial gaps at the
interfaces between the frame and the infill panels are accounted for
by adjusting the properties of interface elements.
The non-linear equations of equilibrium are solved using an
incremental-iterative technique performed under load or displacement
control. The iterative techniques use the standard and modified
Newton-Raphson method or the secant Newton method. An automatic load
incrementation scheme, line searches, and restart facilities are
included.
The capabilities of the program have been examined and
demonstrated by analysing five reinforced concrete panels, a deep
beam, a shear wall, and eight infilled frames. The accuracy of the
analytical results was assessed by comparing them with the
experimental results and those obtained analytically by other workers
and shown to be good.
A study of the effects of some material and numerical parameters
on the results of analyses of reinforced concrete deep beam has been
carried out.
Two techniques have been proposed and used to overcome numerical
problems associated with local strain concentrations which occur with
the displacement control, when path dependent incremental iterative
procedures are used for inelastic materials. The displacement
control provided with these modifications has been shown to be more
efficient than the load control. / Iraqi Government
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