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Open access

Ivona Camelia Petre, Adrian Catangiu, Ileana Nicoleta Popescu, Dan Nicolae Ungureanu, Alexis Daniel Negrea, Aurora Anca Poinescu, Maria Cristiana Enescu, Elena Valentin Stoian and Veronica Despa

Abstract

The aim of the paper was to develop a device (“pin-on-disc” type) for the measurement of friction in plane friction couplings with sliding movement. On tribometric device (made in our laboratory) we can measure the friction force, friction coefficient and wear, for different loading conditions, speeds, time and material coupling.

For the measurement of the frictional force as well as of the coefficients of friction, mainly the method with a resistive tensiometric transducer is used. With a DataQ DI 245 data acquisition board it is possible to record up to 2 kHz frequencies in the range of -10 ÷ +10 mV with a resolution of 13 bits. To test the functionality of the device, a preliminary test was carried out for a steel pin- on- cast iron disc, for different values of the normal pushing force. The device was calibrated and the measurement results were recorded and processed on the computer.

Open access

Florina Violeta Anghelina, Dan Nicolae Ungureanu, Carmen Popa, Elena Valentina Stoian, Ileana Nicoleta Popescu, Cristiana Maria Enescu and Constantin C. Anghelina

Abstract

In this presentation are evidenced instrumental characterization by Electronic Scanning Microscopy (SEM) equipped with EDS / WDS of aluminum alloys such 2024 alloy with multiple synergistic purposes as: acquisition of new knowledge, increase the amount of information obtainable about the material, increasing the efficiency and the quality of the tests, characterization of special destination alloys and assessing their conformity with the specified requirements. In this direction, it requires both the knowledge the test methods (theoretical basis, test method, procedure relating to the method, quality assurance testing) as well material characteristics investigated. These aspects are necessary for test system design, and preliminary interpretation of experimental results.

Open access

Elena Valentina Stoian, Vasile Bratu, Cristiana Maria Enescu and Dan Nicolae Ungureanu

Abstract

Aim of the study is to present the technological process of obtaining cast iron with lamellar graphite for use in the manufacture of cylinder liners, and to identify the main alloying elements and track their influence on the mechanical properties of cast iron with lamellar graphite.

Also paper presents analysis of 20 batches of cast iron with lamellar graphite, which are made of cylinder liners, in terms of chemical composition and the mechanical properties.

After the analysis of the 20 castings of cast iron Fc 250 it is observed that: the increase in the carbon content shows a decrease of the tensile strength and hardness of the gray cast iron; the increase in silicon content shows a decrease in hardness and tensile strength. Decreasing the amount of graphite and especially the alloy of silicon iron lead to hardness increase 1% Si increases hardness by 50 HB). A statistical analysis has been performed on the data obtained that accounts for changes in alloying additions. A modeling and optimization of mechanical properties (tensile strength and hardness) was performed according to the percentages of carbon, silicon and manganese. Mathematical modeling found that the hardness and traction resistance of the cast iron decreased with the increase in carbon, silicon and manganese content.

Open access

Cristian Radu Badea

Abstract

The aim of this paper is to provide an introduction into the inertial motion analysis field, focusing its attention on the analysis that is performed using modern mechatronic inertial motion capture systems, highlighting both the advantages and drawbacks of using such a system and outlining the main constituent elements of these systems as well as the necessary steps to be carried out in order to be able to accomplish such analysis.

A modern mechatronic inertial motion analysis system’s evolution it’s based on MEMS (Micro-Electro-Mechanical-Systems) sensory network, each of which contains a combination of accelerometer, gyroscope, magnetometer. The signals from these MEMS are processed, by a microcontroller, using advanced algorithms in order to provide accurate data regarding body’s segments kinematics, global positioning and magnetic field. Those data are being transferred to a biomechanical model for the analysis. Despite its tremendous advantages, such as portability and real-time analysis capabilities, over alternative motion analysis systems, such as optical or mechanical systems, that based on external transmitters and/or video camera networks, restricting their use to special laboratory conditions and/or large workspace, mechatronic inertial systems are not based on an external infrastructure, they present a major disadvantage, namely the positional drift. The estimation of the human subject body’s segments positions and orientation, absolutely requires an initial calibration procedure, called „sensor to segment calibration”, that starts from the positional and orientation information received from the MEMS network, which are then transferred onto a biomechanical (scaled) model of the human body.

Open access

Vladimir Dragoş Tătaru and Mircea Bogdan Tătaru

Abstract

The wheel is a very important machine part. It is very often found in the construction of the vehicles. Therefore its dynamics must be studied properly. In the paper is presented the dynamical survey of a wheel which climbs on an inclined plane under the action of an active moment produced by an engine. The case of rolling without sliding was taken under consideration in the paper. The approach of the problem is a numerical one. The differential equations describing the movement of the motor wheel were written in matrix form. The paper also presents a method of removing of the constraint forces from the differential equations of motion.

Open access

Dorin Angelescu and Gheorghe Ion Gheorghe

Abstract

Result of the Scientific Concerns from the Doctoral School of Mechanical Engineering and Mechatronics of the Valahia Târgovişte University and the research project of INCDMTM “INTEGRATED MECHATRONIC SYSTEM FOR HUMAN SECURITY INSURANCE FOR THE SAFETY OF OBJECTIVES AND INTERVENTIONS IN RISK - MISO ZONES” (project ID: PED-2016-0924, code PN-III-P2-2.1-PED-2016-0707) in the field of robotics, the scientific work “Intelligent Platform with BLDC Drives and Microsystems for Mechatronic Applications in Security and Surveillance “ is the completion of the experimental testing of controlling the movement of a security and surveillance robot, as part of the Ph.D. industrial thesis “Studies, research and contributions on the development of a smart mecatronic robot for security and surveillance applications”. The scientific work ultimately results in an intelligent, original platform that will be used to control the movement of the robot. The platform allows communication between the latest generation BLDC engine (embedded in the drive wheel) and it’s controller and a computerized microsystem that will handle the displacement controls and will also provide the link with the human operator through any remote guidance system that is used. Although designed for an intelligent security and surveillance mechatronic robot, this platform is proven to be extensively versatile for any other type of robot or mobile platform that uses BLDC wheel-drive engines. The project harmoniously combines Mechatronics, Cyber-MixMeatronic, Integronics and Artificial Intelligence into an Intelligent Interoperable Construction.

Open access

Iulian Ilie and Gheorghe Ion Gheorghe

Abstract

The smart mechatronic microsystem in 4D is designed and built for metrological and indstrial measurements and applications. The intelligent mechatronic system consists of 3 electric linear axes and a rotation system mounted on the linear Z-axis, which increases the capacity of the measuring and positioning system, allowing further expansion of the technical and technological services of the entire mecatronic system by connecting grippers, palpator, stylus module, etc.

Open access

Vladimir Dragoş Tătaru and Mircea Bogdan Tătaru

Abstract

The kinematical study of mechanisms is a very important matter and therefore it must be done very properly. The slidercrank mechanism is very common in engineering applications. The present paper presents an incremental numerical method used for kinematical study of the aforementioned mechanism. The kinematics of the same mechanism is performed using an analytical method. In order to validate the incremental numerical method, the results obtained by using the two methods are then compared.

Open access

Nicolae Angelescu, Dan Nicolae Ungureanu and Vasile Bratu

Abstract

The current work is intended to explain the role of some organic admixtures on the hardened structure of refractory concretes with aluminous cement. The influences on the mechanical-structural properties in the normal hardening but in the heating conditions at different temperatures are emphasized, also. These are due to the influence on the hydration process (i.e. the kind of the neoformations and degree of hydration) and implicitly on the size and distribution of structural pores.

Open access

Nastase-Dan Ciobota and Gheorghe Gheorghe

Abstract

The paper aims to demonstrate the capability of FDM – Fused Deposition Modeling 3D printing technique to build complex structures designed for replacing anatomic parts of human body. It proposes to push the limits of FDM machine in order to achieve both structural integrity, mechanical properties and complexity of the 3D print part. Main applicability focus on bioengineering - developing new, lightweight implants but also can easily extended to airspace/automotive industry.