Vibration of two cantilever beams clamped at one end and connected by a rigid body at the other

2009 ◽  
Vol 23 (2) ◽  
pp. 358-371 ◽  
Author(s):  
Kyung Taek Lee
Keyword(s):  
Rigid Body ◽  
The Other ◽  
Cantilever Beams

scholarly journals Thermally and Mechanically Induced Regelation of Ice

1985 ◽  
Vol 6 ◽  
pp. 135-137
Author(s):  
Kaoru Horiguchi ◽  
R. D. Miller
Keyword(s):  
Rigid Body ◽  
Supercooled Water ◽  
Static Friction ◽  
The Other ◽  
Wall Boundary

At temperatures slightly below 0°C, ice filling a smooth-walled chamber that has porous phase barriers at either end can move through the chamber in a process resembling regelation; supercooled water passes through one barrier and freezes at the same time that ice melts at the other, emerging through the second barrier as supercooled water. The process may be induced mechanically (by differential water pressures at the phase barriers) or thermally {by imposed temperature differentials). The ice moves as a rigid body with slippage at the ice-wall boundary of the chamber. An apparent coefficient of static friction can be deduced and appeared to be about 0.12 for ice at a machined nylon wall at about -0.04 ˚C.

A Pseudo-Rigid-Body Model for Rolling-Contact Compliant Beams

2007 ◽  
Author(s):  
Allen B. Mackay ◽  
Spencer P. Magleby ◽  
Larry L. Howell
Keyword(s):  
Rigid Body ◽  
Rolling Contact ◽  
Model Parameters ◽  
Displacement Curve ◽  
Cantilever Beams ◽  
Body Model ◽  
Rigid Body Model ◽  
Contact Surfaces ◽  
Definition Of ◽  
Force Displacement

This paper presents a pseudo-rigid-body model (PRBM) for rolling-contact compliant beams (RCCBs). The loading conditions and boundary conditions for the RCCB can be simplified to an equivalent cantilever beam that has the same force-deflection characteristics as the RCCB. Building on the PRBM for cantilever beams, this paper defines a model for the force-deflection relationship for RCCBs. The definition of the RCCB PRBM includes the pseudo-rigid-body model parameters that determine the shape of the beam, the length of the corresponding pseudo-rigid-body links and the stiffness of the equivalent torsional spring. The behavior of the RCCB is parameterized in terms of a single parameter defined as clearance, or the distance between the contact surfaces. RCCBs exhibit a unique force-displacement curve where the force is inversely proportional to the clearance squared.

Transient Torque Produced in Arm Shaft of an Industrial Sewing Machine

1990 ◽  
Vol 112 (4) ◽  
pp. 538-543
Author(s):  
N. Muramatsu
Keyword(s):  
Rigid Body ◽  
The Other ◽  
Transient Vibration ◽  
Natural Period ◽  
Sewing Machine ◽  
Triangular Wave ◽  
Pressing Force ◽  
Time Ratio ◽  
Motion System ◽  
Needle Thread

This study considered the effects of needle penetrating force, needle thread tightening tension, and pressing force of the presser foot on torque produced in the arm shaft of an industrial sewing machine. The results obtained are as follows. (1) Penetrating force, especially the initial triangular wave fluctuation, induces noticeable transient vibration in torque. (2) The penetrating force is considerably more transient than the pressing force. The time ratio of the duration of the penetrating force to the natural period of the motion system is close to 1. (3) Consequently, when estimating torque, it is necessary that the arm shaft of the thread take-up lever and needle bar mechanism motion system be considered as elastic. On the other hand, the arm shaft of the feed mechanism motion system can be treated as a rigid body.

Utilizing a Classification Scheme to Facilitate Rigid-Body Replacement for Compliant Mechanism Design

2010 ◽  
Author(s):  
Brian M. Olsen ◽  
Yanal Issac ◽  
Larry L. Howell ◽  
Spencer P. Magleby
Keyword(s):  
Rigid Body ◽  
Mechanism Design ◽  
Classification Scheme ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
The Other ◽  
Design Approach ◽  
Compliant Mechanism Design

The knowledge related to the synthesis and analysis of compliant mechanisms continues to grow and mature. Building on this growth, a classification scheme has been established to categorize compliant elements and mechanisms in a manner that engineers can incorporate compliance into their designs. This paper demonstrates a design approach engineers can use to convert an existing rigid-body mechanism into a compliant mechanism by using an established classification scheme. This approach proposes two possible techniques that use rigid-body replacement synthesis in conjunction with a compliant mechanism classification scheme. One technique replaces rigid-body elements with a respective compliant element. The other technique replaces a complex rigid-body mechanism by decomposing the mechanism into simpler functions and then replacing a respective rigid-body mechanism with a compliant mechanism that has a similar functionality.

Impacted Object Kinematic

2016 ◽  
Vol 827 ◽  
pp. 11-14
Author(s):  
Lubomír Pešík ◽  
Ondřej Kohl
Keyword(s):  
Rigid Body ◽  
Fundamental Problem ◽  
The Other ◽  
Flexible Body ◽  
Main Task ◽  
Dynamic Parameters ◽  
Acceleration Sensor ◽  
Acceleration Sensors ◽  
Time Courses

By destructive car tests are used acceleration sensors for the determination of a time courses of kinematic variables. The main task is to determine the velocity of measured points of selected objects. The fundamental problem in the solution of this problem is the fact that the acceleration sensor simultaneously record two mechanical movements. One of them is the movement of the object as a rigid body and the other is damped vibration of the object itself as a flexible body which is characterized by its dynamic parameters.

Transient Torque Produced in Arm Shaft of an Industrial Sewing Machine

1989 ◽  
Author(s):  
N. Muramatsu
Keyword(s):  
Rigid Body ◽  
Natural Frequency ◽  
The Other ◽  
Transient Vibration ◽  
Natural Period ◽  
Sewing Machine ◽  
Triangular Wave ◽  
Pressing Force ◽  
Motion System ◽  
Needle Thread

Abstract This study considered the effects of needle penetrating force, needle thread tightening tension, and pressing force of the presser foot on torque produced in the arm shaft of an industrial sewing machine. The results obtained are as follows. (1) Penetrating force, especially the initial triangular wave fluctuation, induces noticeable transient vibration in torque. (2) The torsional natural frequency of the arm shaft of the feed mechanism motion system is more than twice that of the thread take-up lever and needle bar mechanism motion system. Penetrating force, according to the relations with the natural period of the system, is considerably more transient than pressing force. (3) Consequently, when estimating torque, it is necessary that the arm shaft of the thread take-up lever and needle bar mechanism motion system be considered as elastic. On the other hand, the arm shaft of the feed mechanism motion system can be treated as a rigid body.

Free Vibration of Stepped and Restrained Cantilever Beams Connected With a Rigid Body: Exact and Numerical Solutions

2000 ◽  
Author(s):  
Hyuck-Dong Kwon ◽  
Young-Pil Park ◽  
Hyun Seok Yang
Keyword(s):  
Mathematical Modeling ◽  
Rigid Body ◽  
Numerical Solutions ◽  
Piezoelectric Materials ◽  
Optical Memory ◽  
Areal Density ◽  
Equation Of Motion ◽  
Cantilever Beams ◽  
Linear Motion ◽  
Tip Mass

Abstract The object of this work is to analyze the dynamic characteristics of the portal closed frame which consists of two stepped beams including a torsional spring at the discontinuous point and a rigid body connecting each beam tips. This system is available in a lot of cases that need higher stiffness and linear motion of the tip mass. For example, it might be used for an optical pick-up actuator, using piezoelectric materials, of the high areal density CD, DVD or the next generation of optical memory devices, which requires super rigidity and linear motion in focusing. The mathematical modeling and the derivation of the equation of motion are given for the beam that is identically paralleled and stepped cantilevers. The equation of motion and the associated boundary and the continuous conditions are analytically obtained by using variational Hamilton’s principle. The exact solutions are presented and compared with the results obtained by the use of the FEM Tool (IDEAS).

Comparison of Methods for Determining Screw Parameters of Finite Rigid Body Motion From Initial and Final Position Data

1989 ◽  
Author(s):  
R. G. Fenton ◽  
X. Shi
Keyword(s):  
Rigid Body ◽  
Rigid Body Motion ◽  
The Other ◽  
Body Motion ◽  
Final Position ◽  
Comparison Of Methods ◽  
Rodrigues Formula ◽  
Position Data ◽  
Data Error

Abstract Five methods for determining the screw parameters of finite rigid body motion using position data of three non-collinear points are compared on the basis of their efficiency, accuracy, and sensitivity to data error. It is found that the method based on Rodrigues’ Formula (Bottema & Roth’s method) is the most efficient. Angeles’ method and Laub & Shiflett’s method provide approximately the same level of accuracy, which is superior to that of the other methods. In terms of sensitivity, Bottema & Roth’s method is preferable On the basis of this study it is recommended that Bottema & Roth’s method to be used if uncertainty exists in the data since it can provide a solution efficiently, accurately, and it is the least sensitive to data error.

Chemical Structure Analysis of a Σ 9 Grain Boundary in α-SiC by Arhvtem

2002 ◽  
Vol 727 ◽  
Author(s):  
Eriko Takuma ◽  
Hideki Ichinose
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Rigid Body ◽  
Chemical Structure ◽  
Boundary Energy ◽  
The Other ◽  
Atomic Resolution ◽  
Grain Boundary Energy ◽  
Transmission Electron

AbstractGrain boundary chemical structure of high purity α silicon carbide was investigated by an atomic resolution high voltage transmission electron microscope (ARHVTEM). Each of a ‘darker’ spots and each of the ‘brighter’ spots in the image have been identified to be silicon (Si) and carbon (C). Two (0001)/(1107) Σ 9 CSL grain boundaries were observed. One boundary showed a rigid body translation of 1/3 <1100> to the component crystals and the other did not. The unit period of the boundary was determined to 2.26 nm along >1120<. Two 6-membered, four 5-membered and 7-membered rings build up the boundary. Each ring consists of three C-C pairs, one Si-Si pair and non-paired Si atoms. In the case without the rigid body translation the number of lone Si atoms are four and only two Si atoms were determined in the other case. The observed structures suggest that the chemical structure of a grain boundary dominantly influences the grain boundary energy.

Comparison of Methods for Determining Screw Parameters of Finite Rigid Body Motion From Initial and Final Position Data

1990 ◽  
Vol 112 (4) ◽  
pp. 472-479 ◽  
Author(s):  
R. G. Fenton ◽  
Xiaolun Shi
Keyword(s):  
Rigid Body ◽  
Rigid Body Motion ◽  
The Other ◽  
Body Motion ◽  
Final Position ◽  
Comparison Of Methods ◽  
Rodrigues Formula ◽  
Position Data ◽  
Data Error

Five methods for determining screw parameters of finite rigid body motion, using position data of three noncollinear points, are compared on the basis of their efficiency, accuracy, and sensitivity to data error. It is found that the method based on Rodrigues’ Formula (Bottema and Roth’s method) is the most efficient. Angeles’ method and Laub and Shiflett’s method provide approximately the same level of accuracy, which is superior to that of the other methods. In terms of sensitivity, Bottema and Roth’s method is preferable. On the basis of this study it is recommended that Bottema and Roth’s method be used if uncertainty exists in the data, since it can provide a solution efficiently, accurately and it is the least sensitive to data error.

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