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Article
Publication date: 7 January 2019

Jiandong Wei, Manyu Guan, Qi Cao and Ruibin Wang

The purpose of this paper is to analyze the cable-supported bridges more efficiently by building the finite element model with the spatial combined cable element.

Abstract

Purpose

The purpose of this paper is to analyze the cable-supported bridges more efficiently by building the finite element model with the spatial combined cable element.

Design/methodology/approach

The spatial combined cable element with rigid arms and elastic segments was derived. By using the analytical solution of the elastic catenary to establish the flexibility matrix at the end of the cable segment and adding it to the flexibility matrix at the ends of the two elastic segments, the flexibility matrix at the end of the cable body is obtained. Then the stiffness matrix of the cable body is established and the end force vector of cable body is given. Using the displacement transformation relationship between the two ends of the rigid arm, the stiffness matrix of the combined cable element is derived. By assigning zero to the length of the elastic segment(s) or/and the rigid arm(s), many subdivisions of the combined cable element can be obtained, even the elastic catenary element.

Findings

The examples in this field and specially designed examples proved the correctness of the proposed spatial combined cable element.

Originality/value

The combined cable element proposed in this study can be used for the design and analysis of cable-stayed bridges. Case studies show that it is able to simulate cable accurately and could also be used to simulate the suspenders in arch bridges as well in suspension bridges.

Details

Engineering Computations, vol. 36 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 March 1998

Alberto Cardona and Alfredo Huespe

Presents an implementation of continuation methods in the context of a code for flexible multibody systems analysis. These systems are characterized by the simultaneous…

Abstract

Presents an implementation of continuation methods in the context of a code for flexible multibody systems analysis. These systems are characterized by the simultaneous presence of elastic deformation terms and rigid constraints. In our formulation, the latter terms are introduced by an augmented Lagrangian technique, resulting in the presence of Lagrange multipliers in the set of unknowns, together with displacement and rotation associated terms. Essential aspects for a successful implementation are discussed: e.g. the selection of an appropriate metric for computing the path following constraint, a flexible description of control parameters which accounts for conservative and nonconservative loads, imposed displacements and imposed temperatures (dilatation effects), and the inclusion of second order derivatives of rigid constraints in the Jacobian. A large set of examples is presented, with the objective of evaluating the numerical effectiveness of the implemented schemes.

Details

Engineering Computations, vol. 15 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 April 1952

William Morse

The work involved in solving certain fixed‐fixed arch problems can be considerably reduced by adopting the clastic centre method.

Abstract

The work involved in solving certain fixed‐fixed arch problems can be considerably reduced by adopting the clastic centre method.

Details

Aircraft Engineering and Aerospace Technology, vol. 24 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 February 1952

William Morse

The work involved in solving certain fixed‐fixed arch problems can be considerably reduced by adopting the classic centre method.

Abstract

The work involved in solving certain fixed‐fixed arch problems can be considerably reduced by adopting the classic centre method.

Details

Aircraft Engineering and Aerospace Technology, vol. 24 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 February 2001

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Abstract

Details

Industrial Robot: An International Journal, vol. 28 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 1 July 1959

In a jet‐propelled aircraft, take‐off and landing is facilitated by arranging laterally disposed jet‐propulsion units 7, 7a for pivotal movement about transverse axes and…

Abstract

In a jet‐propelled aircraft, take‐off and landing is facilitated by arranging laterally disposed jet‐propulsion units 7, 7a for pivotal movement about transverse axes and by the provision of adjustable deflectors 48, 48a, 49, 49a in the jet nozzle of an engine (not shown) mounted in the fuselage. A pilot‐controlled lever 26 controls through a circuit 27 an electromagnetic valve 28 connected to a hydraulic valve 29 controlling through pipes 30, 30a jacks 18, 18a which rotate the engines 7, 7a respectively. A branch circuit 31 from circuit 27 controls a device (not shown) for operating the deflectors 48–49a. The power output of engines 7 and 7a may be controlled by levers 32, 32a connected through control lines 33, 33a to throttle valves (not shown). The elevator, aileron and rudder controls are conventionally operated from the control column 40 and rudder pedals 37 and servo‐control mechanisms such as electrically operated jacks 45, 46 and 47 are inserted in the control rods 38, 41, 43 and 43a respectively. The deflectors 48, 48a are controlled by an electrically operated jack 51 connected to the rudder control rod 38. Similarly, deflectors 49, 49a are controlled by a jack 55 connected to the elevator control rod 41. For the purpose of automatic stabilization the jacks 51 and 55 are further controlled respectively by amplifiers 50 and 56 which receive signals from gyro references 52, 57 and devices 53, 58 responsive to aircraft speed. Lateral stabilization is obtained by connecting the aileron control rods 43, 43a and the throttle valves for engines 7 and 7a to jacks 63, 63a energized from amplifiers 64, 64a supplied with signals from a gyro reference 65 and an aircraft‐speed responsive device 66. A take‐off platform, FIG. 1a (not shown) is described consisting of a fixed base member and an inclinable platform, operated by a cable winch from a horizontal position in which the aircraft is run on to the platform to an inclined position appropriate for take‐off. Ducts are provided in alignment with engines 7 and 7a when in their vertical positions so that exhaust gases may be re‐directed on to the under‐surfaces of the aircraft wings. A warning lamp placed on the ground in view of the pilot is switched off by a cable connected to the aircraft to give the pilot an indication of height in order that he may rotate with safety, the engines 7 and 7a into their forward‐propulsion positions.

Details

Aircraft Engineering and Aerospace Technology, vol. 31 no. 7
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 April 1947

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Notes of the United States…

Abstract

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Notes of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.

Details

Aircraft Engineering and Aerospace Technology, vol. 19 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 January 1991

D.F.H. Wolfe, S.W. Wijesoma and R.J. Richards

Tasks in automated manufacturing and assembly increasingly involve robot operations guided by vision systems. The traditional “look‐and‐move” approach to linking machine…

Abstract

Tasks in automated manufacturing and assembly increasingly involve robot operations guided by vision systems. The traditional “look‐and‐move” approach to linking machine vision systems and robot manipulators which is generally used in these operations relies heavily on accurate camera to real‐world calibration processes and on highly accurate robot arms with well‐known kinematics. As a consequence, the cost of robot automation has not been justifiable in many applications. This article describes a novel real‐time vision control strategy giving “eye‐to‐hand co‐ordination” which offers good performance even in the presence of significant vision system miscalibrations and kinematic model parametric errors. This strategy offers the potential for low cost vision‐guided robots.

Details

Assembly Automation, vol. 11 no. 1
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 July 1996

V.O. Gamarra‐Rosado, G. Fernández, J.C. Grieco, M. Armada and N. Aliane

States that control is of the essence in cybernetics. Summarizes the dynamic equations for a flexible one‐link manipulator moving in the horizontal plane. Employs the…

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447

Abstract

States that control is of the essence in cybernetics. Summarizes the dynamic equations for a flexible one‐link manipulator moving in the horizontal plane. Employs the finite element method, based on elementary beam theory, during the process of formulation. Develops and instruments a one‐link flexible manipulator in order to control its vibration modes. Uses a simple second‐order vibration model which permits vibrations on the rod to be estimated using the hub angle. The validation of the dynamic model and the structural analysis of the flexible manipulator is reached using proper infrared cameras and active light sources for determining actual positions of objects in space. Shows that the performance of the control is satisfactory, even under perturbation action.

Details

Kybernetes, vol. 25 no. 5
Type: Research Article
ISSN: 0368-492X

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Article
Publication date: 1 December 1959

J. Goulder & Sons Ltd., Kinkheaton, Huddersfield, have introduced a machine for checking the lead of helical gears, both internal and external. The generatin mechanism…

Abstract

J. Goulder & Sons Ltd., Kinkheaton, Huddersfield, have introduced a machine for checking the lead of helical gears, both internal and external. The generatin mechanism incorporates a sine bar and steel tape device, setting being by slip gauges. Errors are indicated on a dial or may be recorded. Gears up to 10 in. diameter can be accommodated.

Details

Aircraft Engineering and Aerospace Technology, vol. 31 no. 12
Type: Research Article
ISSN: 0002-2667

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