A Note on the Experimentally-Determined Elastodynamic Response of a Slider-Crank Mechanism Featuring a Macroscopically-Smart Connecting-Rod With Ceramic Piezoelectric Actuators and Strain Gage Sensors

1994 ◽  
Author(s):  
B. S. Thompson ◽  
X. Tao
Keyword(s):  
Strain Gage ◽  
Smart Materials ◽  
Piezoelectric Plate ◽  
Preliminary Investigation ◽  
Theoretical Studies ◽  
Connecting Rod ◽  
Flexural Response ◽  
Elastodynamic Response ◽  
New Generation ◽  
Crank Mechanism

Abstract An experimental investigation is presented into the elastodynamic flexural response of a smart flexible connecting-rod of a planar slider-crank mechanism which features both macroscopic actuators and sensors. This connecting-rod was synthesized with two thin PZT ceramic piezoelectric plate actuators bonded to the flanks of the beam-like member at the mid-span of the link, which were employed to reduce the magnitude of the flexural response when they were activated by amplified signals emulating from two strain gage sensors bonded to the surfaces of the piezoceramic actuators. The authors believe that this is the first paper to present experimental results for a linkage featuring this class of smart materials, and these results will hopefully motivate more theoretical studies on mechanism systems fabricated from this class of biomimetic materials. The results from this preliminary investigation add credibility to the proposition that this new generation of macroscopically smart materials will have a significant role to play in the design of the next generation of machines and mechanisms.

Vibration Analysis of the Flexible Connecting Rod With the Breathing Crack in a Slider-Crank Mechanism

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Yan-Shin Shih ◽  
Chen-Yuan Chung
Keyword(s):  
Governing Equation ◽  
Moving Boundary ◽  
Beam Theory ◽  
Crack Model ◽  
Breathing Crack ◽  
Connecting Rod ◽  
Bernoulli Beam ◽  
The Galerkin Method ◽  
Euler Bernoulli Beam ◽  
Crank Mechanism

This paper investigates the dynamic response of the cracked and flexible connecting rod in a slider-crank mechanism. Using Euler–Bernoulli beam theory to model the connecting rod without a crack, the governing equation and boundary conditions of the rod's transverse vibration are derived through Hamilton's principle. The moving boundary constraint of the joint between the connecting rod and the slider is considered. After transforming variables and applying the Galerkin method, the governing equation without a crack is reduced to a time-dependent differential equation. After this, the stiffness without a crack is replaced by the stiffness with a crack in the equation. Then, the Runge–Kutta numerical method is applied to solve the transient amplitude of the cracked connecting rod. In addition, the breathing crack model is applied to discuss the behavior of vibration. The influence of cracks with different crack depths on natural frequencies and amplitudes is also discussed. The results of the proposed method agree with the experimental and numerical results available in the literature.

scholarly journals Design of a prototype of an engine mechanism with rotating cylinders

2020 ◽  
Vol 318 ◽  
pp. 01004
Author(s):  
Miroslav Blatnický ◽  
Ján Dižo
Keyword(s):  
High Speed ◽  
Cooling System ◽  
Ambient Air ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Rotating Cylinders ◽  
Liquid Cooling ◽  
Working Cycle ◽  
Liquid Cooling System ◽  
Crank Mechanism

In this article, authors focus on the design and construction of a real prototype of an engine mechanism with rotating cylinders and its using mainly in piston combustion engines. It is assumed, that the normal force of a piston will be completely eliminated, because the swing angle of a connecting rod will equal to zero during the whole working cycle, since the connecting arm of the piston moves just the cylinder axis. It will by allowed by the conceptual design of the mechanism presented in this article. As rotating blocks of cylinders concurrently act as a flywheel, it is proposed, that in this way there is possible to save the mass of additional flywheels. Moreover, liquid cooling system is not necessary, because the rotating cylinders sufficiently transfer heat to ambient air. In addition, the output of torque will be reached without necessity of gear transmission, which results to decreasing of needs of mechanism lubrication. Other advance of the designed mechanism are two outputs. The first output is low-speed and it goes out from rotating cylinders, i. e. from the slider-crank mechanism with revolutions n1. The other output is high-speed, from the crankshaft with revolutions n2. Because of more favourable properties of the mechanism, authors have decided to create a real device to confirm all mentioned advantages of the mechanism by the suitable way.

Vibrations of Elastic Connecting Rod of a High-Speed Slider-Crank Mechanism

1971 ◽  
Vol 93 (2) ◽  
pp. 636-644 ◽  
Author(s):  
Peter W. Jasinski ◽  
Ho Chong Lee ◽  
George N. Sandor
Keyword(s):  
Small Parameter ◽  
High Speed ◽  
Elastic Stability ◽  
Method Of Averaging ◽  
Connecting Rod ◽  
Transverse Vibrations ◽  
Elastic Bar ◽  
The Moment ◽  
Steady State Solutions ◽  
Crank Mechanism

The research involved in this paper falls into the area of analytical vibrations applied to planar mechanical linkages. Specifically, a study of the vibrations, associated with an elastic connecting-bar for a high-speed slider-crank mechanism, is made. To simplify the mathematical analysis, the vibrations of an externally viscously damped uniform elastic connecting bar is taken to be hinged at each end (i.e., the moment and displacement are assumed to vanish at each end). The equations governing the vibrations of the elastic bar are derived, a small parameter is found, and the solution is developed as an asymptotic expansion in terms of this small parameter with the aid of the Krylov-Bogoliubov method of averaging. The elastic stability is studied and the steady-state solutions for both the longitudinal and transverse vibrations are found.

The Impact of Nationalism on Albanian–Slav Relations in Late Ottoman Macedonia: A Historiographical Review

2019 ◽  
Vol 47 (6) ◽  
pp. 1117-1130
Author(s):  
Fabio Bego
Keyword(s):  
Cold War ◽  
Preliminary Investigation ◽  
The Past ◽  
Ottoman Balkans ◽  
Historical Accounts ◽  
The Cold War ◽  
New Generation ◽  
The Impact ◽  
Late Ottoman

AbstractThe aim of this article is to inquire how recent and more consolidated historiographical trends consider the impact of nationalism in the late Ottoman Balkans. I focus on historical accounts of Albanian–Slav interaction in the late Ottoman Macedonian context, although the inquiry also includes texts that do not only engage with this epistemological field. I confront research efforts that have been published from the early 1960s to the present in order to understand the continuities and the discontinuities that characterize the work of historians. A preliminary investigation has allowed me to outline two main historiographical approaches: the national historiographies and the postnationalist approach. Such a distinction has become tangible especially after the end of the Cold War when a new generation of historians started to question the validity of the studies conducted by their colleagues in the past decades by pointing at the methodological and ideological issues that limited their work. In this article I evaluate to what extent the work of postnationalist historians is different from that of traditional historiographies and finally reflect on the possibility and benefits that might come from a dialogue between the two approaches.

Purpose-built metal oxide nanomaterials. The emergence of a new generation of smart materials

2000 ◽  
Vol 72 (1-2) ◽  
pp. 47-52 ◽  
Author(s):  
Lionel Vayssieres ◽  
Anders Hagfeldt ◽  
Sten Eric Lindquist
Keyword(s):  
Interfacial Tension ◽  
Metal Oxide ◽  
Nanostructured Materials ◽  
Smart Materials ◽  
Aging Process ◽  
Structural Requirements ◽  
Thermodynamic Stabilization ◽  
Metal Oxide Nanomaterials ◽  
Growth And Aging ◽  
New Generation

A new concept has been developed in order to achieve a new generation of smart materials, namely purpose-built materials, modeled and designed to match the physical and structural requirements of their applications. A model based on the thermodynamic monitoring of the nucleation, growth, and aging process of metal oxide by minimization of the interfacial tension, yielding to the thermodynamic stabilization of the system, results in well-designed and well-ordered nanostructured materials with the required porosity, morphology, size, and orientation on various substrates.

Balancing the Moments of a VR5 Engine Taking into Account a Desaxial Crank Mechanism and Cylinder Camber Angle

2020 ◽  
pp. 41-49
Author(s):  
N.D. Chainov ◽  
P.R. Vallejo Maldonado
Keyword(s):  
Relative Displacement ◽  
Working Fluid ◽  
Inertial Forces ◽  
Structural Elements ◽  
Connecting Rod ◽  
Cylinder Axis ◽  
Acoustic Characteristics ◽  
Camber Angle ◽  
Inertia Forces ◽  
Crank Mechanism

Automobile piston engines with a desaxial crank mechanism are characterized by increased vibration activity associated with a cyclic change in the pressure of the working fluid in the cylinders and inertial forces associated with the reciprocating and rotational movement of the crank mechanism moving masses. Properties reflecting the consumer properties of the engine, including acoustic characteristics, are largely determined by the level of vibration of the structural elements of the desaxial crank mechanism and, first of all, by the balance of inertial forces during operation. The article discusses balancing of five-cylinder four-stroke VR type engines with a desaxial crank mechanism and uniform flash alternation. The authors introduce formulas that can be used to determine and analyze moments of the inertia forces of the reciprocating and rotating masses arising in VR5 engines at the set values of the cylinder camber angle, the ratio of the crank radius to the connecting rod length and the relative displacement of the cylinder axis. A method of balancing the moments of inertia forces of the reciprocating and rotating masses is proposed.

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