Mechanics and Control
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ISSN 2083-6759
e-ISSN: 2300-7079
Issue Date
2011
Volume
Vol. 30
Number
No. 1
Description
Journal Volume
Mechanics and Control
Vol. 30 (2011)
Projects
Pages
Articles
The use of evolution algorithms for identification of transmission backlash
(2011) Korbel, Krzysztof; Zygmunt, Henryk
Mechanical propulsion system including, inter alia, an electric motor, shaft and transmission is characterized by certain parameters whose values cannot be calculated using mathematical methods (transmission backlash) or may vary during operation time. Such parameters have to be known to ensure proper operation of the system. In this article a method for identification of these parameters is described. The method is based on an evolution algorithm. This algorithm utilizes natural selection methods and natural transformation processes within a population, similar to those in animal world. The least-fit individuals are rejected by applying the fitness function. The population will improve, and in infinite time it will be perfect. That means that the perfect solution can be attained in a very long time. This time can be shortened by defining the termination criteria, e.g. the identification can be stopped if one of the population individuals has a very low error. Such identification requires a transition function (model), as well as reference measurement made on a real system.
Design of the laboratory stand for testing vehicle suspensions
(2011) Kowal, Janusz; Snamina, Jacek; Wzorek, Tomasz
This paper is devoted to the designing of the laboratory stand for testing car vehicle suspensions. Main parts of the laboratory setup are as follows: a frame construction with vehicle suspension elements, an electro-hydraulic shaker, a hydraulic power supply unit and a measurement and control system. This work provides preliminary analysis of the laboratory setup such as static analysis and dynamic simulations of the system. Results of the calculations were used in the designing process of the laboratory setup.
Laboratory stand for testing the active vibration control system with energy regeneration
(2011) Orkisz, Paweł
The paper describes an active vibration control system for a structure of two degrees of freedom. The system comprises two elastically connected bodies moving along vertical guides. The system structure is additionally provided with two electrodynamical linear motors working in energy regeneration and active vibration reduction subsystems. The combination of these subsystems with a special control system creates a self-powered vibration reduction system, allowing active vibration control of the second body using the energy from the motion of the first body, which was regenerated and stored in capacitors.
TiNi shape memory alloy tension at various temperatures - infrared imaging of shape memory effect and pseudoelasticity
(2011) Pieczyska, Elżbieta; Tobushi, Hisaaki
The mechanical characteristics and the infrared imaging of stress-induced martensite transformation developing in TiNi shape memory alloy (SMA) subjected to tension in various conditions with respect to the SMA austenite finish parameter have been presented. Based on the mechanical curves and their related temperature changes it was found that onset of the martensitic transformation appears at the end of the elastic part of the stress-strain curve, since the temperature starts to increase before the knee in the curve. The uniform temperature distribution observed on the specimen surface at this stage confirms that the initial martensite transformation is macroscopically homogeneous. For the shape memory effect behavior the uniform temperature distribution on the specimen surface was observed during the complete process of the SMA loading which means that the transformation process is macroscopically homogeneous. For the shape memory alloy pseudoelasticity behavior bands of higher temperature have been recorded during the specimen loading and bands of lower temperature during its unloading, manifesting localized Lü ,ders-like deformation, caused by the transformation process. As the transformation advances, the higher temperature changes have been recorded. Taking advantages from the infrared technique a new results concerning nucleation and development of the martensite forward and reverse transformation have been obtained. Finally, some examples of the SMA new applications due to the SMA shape memory effect have been presented and discussed.
Computational modelling of localized deformations with regularized continuum models
(2011) Pamin, Jerzy
The paper presents a short overview of selected problems related to the numerical analysis of localized deformations. After defining the localization phenomenon and the class of gradient models, two simulation examples are shown. They are applications of the plasticity theory with a Laplacian of the hardening parameter and of the damage theory with an additional averaging equation for an equivalent strain measure.