Research on Minimum Pressure Angle of Bennett Linkage

2019 ◽  
Author(s):  
Lele Bai ◽  
Lubin Hang ◽  
Xiaobo Huang ◽  
Mingyuan Wang ◽  
Ziyu Liu
Keyword(s):  
Twist Angle ◽  
Kinematic Model ◽  
Analytic Formula ◽  
Geometric Meaning ◽  
Output Link ◽  
Deployable Structures ◽  
Minimum Pressure ◽  
Pressure Angle ◽  
Important Index ◽  
Space Deployable Structures

Abstract Space deployable structures that are constructed by the single loop over-constrained linkages have been extensively applied in the fields of aerospace and construction. The pressure angle regarded as an important index to measure the performance of the basic units has attracted more and more attention. The kinematic model of the Bennett linkage is studied by the D-H matrix and the analytic formula of the pressure angle has been deducted through kinematic equations. The rule of the Bennett linkage has been discovered that the minimum pressure angle occurs while the input angle equals nπ + π / 2(n ∈ N). According to the linkage configuration at the input angle of π / 2, the geometric meaning is revealed that the minimum pressure angle of the linkage is the same as the twist angle of the joint axes of the output link. Finally, conclusions can also be drawn that the smaller the twist angle of the output link is, the smaller the minimum pressure angle will be. The research enriches the kinematics of Bennett linkage and provides a reference for its engineering applications.

Initial Estimates in the Design of Rack-and-Pinion Steering Linkages

2000 ◽  
Vol 122 (2) ◽  
pp. 194-200 ◽  
Author(s):  
P. A. Simionescu ◽  
M. R. Smith
Keyword(s):  
Synthesis Method ◽  
Geometric Parameters ◽  
Degree Of Freedom ◽  
Minimum Pressure ◽  
Pressure Angle ◽  
Early Stages ◽  
Design Charts

Based on recent results concerning the occurrence of function cognates in Watt II linkages, it is shown that only 3 geometric parameters are sufficient for defining the kinematic function of simplified planar rack-and-pinion steering linkages. The steering performances of the mechanisms are analytically expressed in terms of these parameters and, by employing an optimization-based synthesis method involving increasing the degree of freedom of the mechanism, the optimum domains are determined. The parameter sets corresponding to these minimum steering error domains are displayed in design charts. These charts aid the automotive engineer in the early stages of conceiving a new steering linkage by providing initial estimates of the basic geometry of the mechanism. They also provide information on two other characteristics of concern, i.e. the minimum pressure angle occurring in the joints and the rack stroke required for maximum turn of the wheels. [S1050-0472(00)00402-5]

scholarly journals Analysing the Kinematic Characteristics of Bennett Mechanisms and Its Networks for Usage in Forming Deployable Structures

Mechanika ◽  
2019 ◽  
Vol 25 (4) ◽  
pp. 269-275
Author(s):  
Tony punnoose Valayil ◽  
Selladurai Velappan ◽  
Prakash Lakshmana Pandian
Keyword(s):  
Angular Velocity ◽  
Angular Displacement ◽  
Twist Angle ◽  
Angular Acceleration ◽  
Singularity Analysis ◽  
Equal Length ◽  
Simulation Environment ◽  
Deployable Structures ◽  
Saddle Surface ◽  
Saddle Shape

Two types of bennett mechanism are      encountered in most of the related literatures. This research aims at finding the best type of bennett mechanism out of the two and then using it for suitable application. One type of bennett mechanism is known as equilateral bennett mechanism, which has all the four kinematic links of equal lengths. Next type is a bennett mechanism having their opposite links of equal length. Using the two types of bennett mechanism, two different networks are created. Their working range, minimum foldability and maximum foldability of the networks were identified using MATLAB-SimMechanics toolbox. Thus, the network having better foldability was identified, so that it can be used for making foldable tent application, which is a deployable structure. The results from the analysis prove that equilateral bennett mechanism had better foldability than its counterpart. Then on analyzing the shapes of the networks, it was found that the networks had a saddle shape. The obtained saddle surface provided certain results like, when the twist angles of the bennett links were varied, saddle surfaces with more steepness are obtained. The influence of twist angle on angular displacement, angular velocity, and angular acceleration of the mechanism were also analyzed. Singularity analysis of these networks was done in Matlab-SimMechanics simulation environment. Coupler curves for both types of bennett mechanism were plotted to identify the trajectory of the output links

Deployable Prismatic Structures With Origami Patterns

2014 ◽  
Author(s):  
Sicong Liu ◽  
Weilin Lv ◽  
Yan Chen ◽  
Guoxing Lu
Keyword(s):  
Design Method ◽  
Kinematic Model ◽  
The Other ◽  
Dihedral Angles ◽  
Geometric Condition ◽  
Compatibility Conditions ◽  
Deployable Structures ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Geometric Compatibility

In order to find the general condition of the rigid origami pattern for the deployable prismatic structures, the kinematic model is proposed based on the mobile assemblies of spherical 4R linkages. The kinematic and geometric compatibility conditions of the mobile assemblies are derived. Two groups of 2n-side deployable prismatic structures are obtained. When n=2, one of them is with kite-shape intersection, while the other is with parallelgram. The variations of the unit are discussed. The straight and curvy multilayer prisms are built by changing the dihedral angles between the intersecting planes. The general design method for the 2n-side multilayer deployable prismatic structures is proposed with the geometric condition of the origami patterns. All the deployable structures constructed with this method can be deployed and folded along the central axis of the prisms with single degree of freedom, which makes the structures have wide engineering applications.

scholarly journals Local deformation method for measuring element tension in space deployable structures

2017 ◽  
Vol 102 ◽  
pp. 01007 ◽  
Author(s):  
Sergey Belov ◽  
Mikhail Pavlov ◽  
Viktor Ponomarev ◽  
Sergey Ponomarev
Keyword(s):  
Local Deformation ◽  
Deformation Method ◽  
Deployable Structures ◽  
Measuring Element ◽  
Space Deployable Structures

scholarly journals Design and experiment of a passive damping device for the multi-panel solar array

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401668796 ◽  
Author(s):  
Yongfang Kong ◽  
Hai Huang
Keyword(s):  
Technology Development ◽  
Test Sample ◽  
Solar Array ◽  
Response Analysis ◽  
Finite Element Models ◽  
Space Technology ◽  
Structural Damping ◽  
Deployable Structures ◽  
Space Deployable Structures ◽  
Design Guidance

With the space technology development, large flexible space deployable structures have been used widely. Studying on the vibration control for large flexible space deployable structures becomes very important. In this study, a novel passive vibration damping device is developed for the multi-panel sun-orientated deployable solar array. Its upper strut contains a viscous damper while the lower strut is rigid. The device is lockable and located near the solar array root hinge to increase the structural damping without reducing the fundamental frequency. This design will not influence the original functions of the solar array, such as folding, deploying, and sun tracking. The corresponding finite element models are established, and the properties of the damping device are investigated by modal analysis and transient response analysis. The damping mechanism design for a certain type of solar array is presented. The associated modal tests based on a solar array test sample verify the effectiveness of the device. Conclusions are drawn to help define design guidance for future damping device implementations.

Active Moving Polymers and Multifunctional Composites: Shape the Future Structures

2013 ◽  
Vol 745 ◽  
pp. 129-134 ◽  
Author(s):  
Jin Song Leng
Keyword(s):  
Smart Materials ◽  
Biomedical Engineering ◽  
Composite Structures ◽  
Shape Memory Polymer ◽  
Multifunctional Composites ◽  
Deployable Structures ◽  
Wide Range ◽  
Space Deployable Structures ◽  
Short Carbon

Smart materials can be defined as the materials that have the capability of sensing and reacting to environmental conditions or stimuli. In recent years, a wide range of novel smart materials have been developed, the applications of which now cover various important fields including aerospace, automobile, telecommunications, and so forth. This talk mainly focuses on recent progresses of Active Moving Polymer (i.e. Shape Memory Polymer, SMP), and SMP based composite structures, as well as their applications including aerospace, astronautics and biomedical engineering. This presented work summarizes the recent advances in novel SMP including epoxy-based SMP, styrene-based SMP, cyanate ester-based SMP, polyurethane-based SMP, multiple SMP, design and characterization of SMP composites (SMPCs) filled with nickel chains, short carbon fiber, carbon nanotube chains, carbon nanopaper, and so on. The SMP stimulus methods, including heat, electric, light, magnetic field, and solvent have been introduced. The application of SMPCs used in aircraft morphing and space deployable structures is also investigated.

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