Calculation and Analysis on Out-Plane Force of Hollow-Shearwall in Large Space Residence

2010 ◽  
Vol 163-167 ◽  
pp. 1396-1402 ◽  
Author(s):  
Lang Cao ◽  
Wei Weng

For new large space plate-wall structure, the out-of-plane problems of shearwall caused by vertical loads cannot be ignored. The out-of-plane stiffness can be increased by introducing Hollow-shearwall. However, currently rare attention has been focused upon research on the out-of-plane problems of hollow-shearwall. Based on the theory of elastic thin plate,the hollow-shearwall is regarded as an orthotropic plate in this paper. According to the actual situation of the loading on the shearwall, it is the first time that the analytic solution of the hollow-shearwall with different boundary constraints under the combined action of the end moment and vertical pressure has been derived in this paper. The numerical results by the program developed with Mathematical based on the analytic solution are compared with those obtained with ANSYS and it shows that this method is correct and reliable. Under various operating conditions, it is easy to apply this program for the out-of-plane force analysis, which can provide reference for the further research on the out-of-plane capacity and a reliable basis for engineering design.

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Shu Wang

The volumetric efficiency is one of the most important aspects of system performance in the design of axial piston pumps. From the standpoint of engineering practices, the geometric complexities of the valve plate (VP) and its multiple interactions with pump dynamics pose difficult obstacles for optimization of the design. This research uses the significant concept of pressure carryover to develop the mathematical relationship between the geometry of the valve plate and the volumetric efficiency of the piston pump. For the first time, the resulting expression presents the theoretical considerations of the fluid operating conditions, the efficiency of axial piston pumps, and the valve plate designs. New terminology, such as discrepancy of pressure carryover (DPC) and carryover cross-porting (CoCp), is introduced to explain the fundamental principles. The important results derived from this study can provide clear recommendations for the definition of the geometries required to achieve an efficient design, especially for the valve plate timings. The theoretical results are validated by simulations and experiments conducted by testing multiple valve plates under various operating conditions.


2018 ◽  
Vol 70 (5) ◽  
pp. 838-845 ◽  
Author(s):  
N.B. Naduvinamani ◽  
Shridevi S. Hosmani

Purpose The purpose of this study is to examine the magneto-hydrodynamic (MHD) effect on porous exponential slider bearings lubricated with couple stress fluid and to derive the modified Reynolds’s equation for non-Newtonian fluid under various operating conditions to obtain the optimum bearing parameters. Design/methodology/approach Based upon the MHD theory and Stokes theory for couple stress fluid, the governing equations relevant to the problem under consideration are derived. This paper analyzes the effect on porous exponential slider bearings with an electrically conducting fluid in the presence of a transverse magnetic field. Semi-numerical solutions are obtained and discussed. Findings It is found that there is an increase in the load carrying capacity, frictional force and decrease in the co-efficient of friction in porous bearings due to the presence of magnetic effects with couple stress fluid. Originality/value This study is relatively original and gives the MHD effect on porous exponential slider bearings lubricated with couple stress fluid. The author believes that the paper presents these results for the first time.


Author(s):  
Simone Marchetti ◽  
Duccio Nappini ◽  
Roberto De Prosperis ◽  
Paolo Di Sisto

Abstract This paper describes the design of the Free Power Turbine (FPT) of the LM9000, in particularly the design of its Passive Clearance Control (PCC) system. The LM9000 is the aero-derivative version of the GE90-115B jet engine. Its core engine has many common parts with the GE90; what differs is the booster (low pressure compressor) and the lower pressure turbine (LPT). The booster of the LM9000 is without fan because the engine is not used to provide thrust but torque only, subsequently it has a new flow path [5]. The LPT has instead been replaced by an intermediate pressure turbine (IPT) and by the FPT. The IPT drives the booster, while the FPT is a free low-pressure turbine designed for both power generation and mechanical drive industrial applications, including LNG production plants. Due to its different application, the LM9000 FPT flow path differs sensibly from the GE90 LPT, however as the GE90 it is provided of a clearance control system that cools the casing in order to reduce its radial deflection. It is not the first time that a clearance control system has been used in industrial applications; in GE aero-derivative power turbines is already present in the LM6000 and LMS100. Design constraints, system complexity, high environment variability because the PCC is located outside the GT, harsh environments and long periods of usage still make the design of this component challenging. The design of the PCC has been supported by extensive heat transfer and mechanical simulations. Each PCC component has been addressed with a dedicated life calculation and all the blade and seal clearances have been estimated for all the operating conditions of the engine. Simulations have been validated by an extensive test campaign performed on the first engine.


2011 ◽  
Vol 137 ◽  
pp. 159-166
Author(s):  
Ying Zeng Zhu ◽  
Fei Gao ◽  
Jun Dong Kong

This paper aims at research on fundamental principles of long concrete wall cracks in basement on the basis of series basic experiments and engineering practices. Relying on typical project, we use ABAQUS finite element analysis software to conduct simulation analysis to provide evidence for integrated control of cracks. Simulation analysis results show that the reinforcement stresses has tight connections with constraint mode of structure, for instance, column side and the location connected with foundation; effective limits of boundary constraints to structure deformation and constraints of free-form deformation on long wall structure make the concentration of reinforcement stresses nearing constraint location relatively obvious; under the effects of temperature and contraction, internal force of concrete wall will be re-distributed, therefore, reinforcement stress of concrete can not directly reveal actual force distribution inside the wall, but the overall trend is close to concentrated pattern of reinforcement stress.


SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2470-2481 ◽  
Author(s):  
JiaoJian Yin ◽  
Dong Sun ◽  
Yousheng Yang

Summary The pump dynamometer card is a direct reflection of the operating conditions of the downhole pump, which is important for the diagnosis of sucker-rod pumping systems. In this paper, we propose a novel diagnostic method based on the estimation of the parameters from the polished-rod load vibration signal of sucker-rod pumping systems in a vertical well. In this study, we deduce a new analytic solution of the 1D wave equation of the sucker-rod string, which can be used for the predictive and diagnostic analyses. The relationship between the polished-rod load vibration and the pump equivalent impulse load based on the analytic solution is studied, and the diagnostic parameter estimating method is proposed. Therefore, the pump dynamometer card calculated method based on the surface dynamometer card is realized. This study shows that the method is efficient.


2018 ◽  
Vol 230 ◽  
pp. 01017
Author(s):  
Anatoliy Shtompel ◽  
Liudmyla Trykoz ◽  
Dmytro Borodin ◽  
Andrii Ismagilov ◽  
Yaroslav Chmuzh

The permanent way components are of key importance for safe operation of a rail way. The country regulations, in particular in Ukraine, specify the operational life limits for the permanent way but they do not define any tool or method to predict deterioration of the permanent way condition over time. The study is aimed to develop a method for assessing failure risk of the permanent way components in operation. There was a method offered to evaluate risk of failure of the permanent way components of the welded tracks, which considers accumulated freight load on a rail section. Each element of the permanent way, such as rails, fasteners, sleepers, ballast layer, accumulates defects and deformations. The accumulation rate is different for the above components and depends on freight traffic. There was probability of failure-free operation calculated for each component for the first time and an integral fatigue index of the construction has been offered which considers freight traffic accumulated load. There was a mathematical failure forecast model developed which allows planning of track maintenance. The model allows to take into account operating conditions of a railway section. The results of simulation are presented in various diagrams.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Chen Qiu ◽  
Peng Qi ◽  
Hongbin Liu ◽  
Kaspar Althoefer ◽  
Jian S. Dai

This paper for the first time investigates the six-dimensional compliance characteristics of orthoplanar springs using a compliance-matrix based approach, and validates them with both finite element (FEM) simulation and experiments. The compliance matrix is developed by treating an orthoplanar spring as a parallel mechanism and is revealed to be diagonal. As a consequence, corresponding diagonal compliance elements are evaluated and analyzed in forms of their ratios, revealing that an orthoplanar spring not only has a large linear out-of-plane compliance but also has a large rotational bending compliance. Both FEM simulation and experiments were then conducted to validate the developed compliance matrix. In the FEM simulation, a total number of 30 types of planar-spring models were examined, followed by experiments that examined the typical side-type and radial-type planar springs, presenting a good agreement between the experiment results and analytical models. Further a planar-spring based continuum manipulator was developed to demonstrate the large-bending capability of its planar-spring modules.


2001 ◽  
Vol 695 ◽  
Author(s):  
Ning Tang ◽  
Roxann L. Engelstad ◽  
Edward G. Lovell

ABSTRACTThe Point-Deflection Method is a potentially useful technique for measuring the internal stresses of freestanding thin films. By applying a small concentrated transverse load at the center of a pre-stretched film, and measuring the corresponding out-of-plane displacement at appropriate locations, the average internal stress can be readily determined. The load-deflection relationship has been derived for both circular and rectangular shapes. The method involves no additional micromachining in sample preparation and has low sensitivity to the variations in boundary constraints. Its feasibility has been further substantiated with finite element simulations from a variety of perspectives, as well as experimental correlations from the stress measurements of a photomask pellicle film.


Author(s):  
Haley L. Gomez ◽  
Edward L. Gomez ◽  
Peter Hargrave

AbstractThe Herschel Space Observatory is ESA's fourth Cornerstone mission and will be the largest, most sensitive telescope ever put into space. It will be the first space observatory to observe from the far-infrared to the submillimetre waveband, unveiling the cool, hidden universe for the first time. Herschel will observe stars and galaxies at the stage of formation and discover where all the cosmic dust polluting galaxies comes from. Given the huge public interest in large space missions such as Hubble and Spitzer, Herschel is an ideal opportunity to excite and inform the UK public during the International Year of Astronomy 2009. Here we present some of the education and outreach projects created by the Herschel Outreach Group (HOG).


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