Arhivă — Seria D

1

KINEMATICS AND DYNAMICS OF A 2-DOF ORIENTING GEAR TRAIN

Stefan STAICU, Iulian TABARA, Ovidiu ANTONESCU

Recursive matrix relations for kinematics and dynamics analysis of a 2-DOF orienting gear train are established in this paper. The mechanism is a parallel system with five moving parts and three bevel gear pairs controlled by two electric motors. Knowing the rotation motion of the end-effector, the inverse dynamic prob…

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2

ULTRASONIC GUIDED WAVES SENSITIVITY TO FLAWS NEAR PLATE EDGE

Mihai Valentin PREDOI, Adina NEGREA

Ultrasonic guided waves represent a modern Structural Health Monitoring (SHM) technique used in light structures like those from the aeronautical industry. The guided waves propagate along plates for considerable distances, being thus capable to indicate the presence of flaws. One method to generate such Lamb waves is …

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3

DESIGN OF AN ANTHROPOMORPHIC UPPER LIMB EXOSKELETON ACTUATED BY BALL-SCREWS AND CABLES

Philippe GARREC

This paper presents the design of ABLE, an anthropomorphic upper limb exoskeleton integrally actuated by highly reversible ball-screw and cable (SCS standing for Screw-and-Cable-System) allowing true joint torque control without force sensor. Their unique kinematics allows their integration in the structure thanks to d…

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4

TRANSFER MATRIX METHOD FOR FORCED VIBRATIONS OF BARS

Valentin CEAUªU, Andrei CRAIFALEANU, Cristian DRAGOMIRESCU

The paper presents the transfer matrix method, applied to forced vibrations of straight bars. The case of axial vibrations is considered, of bars with discontinuously variable cross-section, acted upon by concentrated perturbation forces. Some relatively simple applications are also presented.

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5

ROBUST ACTIVE CONTROL LAW WITH INTERNAL MODEL FOR VIBRATION ATTENUATION

Eliza MUNTEANU, Ioan URSU

The present work continues some recent researches of the authors ([1], [2]) in the vibration active control domain for a composite wing model by using MFC (Macro-Fiber-Composite) piezo actuators. The robustness characteristics of the optimal control LQR (Linear Quadratic Regulator) are recovered by the Kalman filter …

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6

BEHAVIOR OF TOWER CRANES UNDER SEISMIC ACTIONS

Mircea ALÃMOREANU, Andrei VASILESCU

The behavior of tower cranes fixed on the buildings was studied in two previous papers considering the simplified hypothesis that the saddle jib has the direction of seismic wave propagation. Two dynamical models were considered with one degree of freedom for the “out of service” cranes (without load) and respectively,…

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7

A METHOD FOR COMPUTATION OF THE MAXIMUM PRINCIPAL STRESS FOR AN ELIPTICAL BULBOUS BOW DURING THE HYDRODYNAMIC IMPACT

Adrian POPA, Vergil CHIÞAC

This works makes an analysis of the maximum principal stress which occur during a hydrodynamic impact for different types of bulbs withs impact speeds from 1 to 10 m/s.

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8

FEEDBACK DESIGN METHOD FOR DESIRED LONGITUDINAL STABILITY CHARACTERISTICS

Bogdan C. TEODORESCU

In the present paper an original feedback design method is proposed for improving aircraft longitudinal stability characteristics.\r\nAssuming a proportional feedback structure, the algebraic inequality-type constraints that define a prescribed level of flying qualities are transposed analytically into admissible feedb…

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9

AUTOMATIC DETERMINATION OF GRINDING TOOL PROFILE FOR HELICAL SURFACES MACHINING USING CATIA/VB INTERFACE

Sa¹a ÆUKOVIÆ, Goran DEVED®IÆ, Ionuþ GHIONEA

According to the specific requirements in automotive industry and adopted principles of CAD modeling using macros, a parametric model of involute helical surface that corresponds to skeletal cylindrical helix is developed. This model represents knowledge and experience of designers through definition of relational depe…

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10

PROJECT RISK ASSESSMENT REGARDING INDUSTRIAL ROBOTS IMPLEMENTATION IN PRODUCTION SYSTEMS

Constantin ISPAS, Bogdan-Ion LUNGU

Developing strategies for effective and efficient risk assessment throughout a project implementation requires risk identification and analysis, use of techniques that incorporate effective decision considerations about adverse events, likelihood and consequences of undesirable events and assessment of weaknesses. The …

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11

EXPERIMENTAL MEASUREMENT OF CUTTING EFFORTS AT MILLING ZINC ALLOYS

Ioan CÃLINESCU, Constantin MINCIU, Claudiu BΪU

The paper presents the experimental stand for cutting efforts measurement, results of the experimental research and their interpretation for the milling zinc alloys. Finally, the exponential regression functions to determine these cutting forces and torques depending on the cutting regime parameters.

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12

STATIC STIFFNESS OF TURNING TOOLS

Ioan POPESCU, Sergiu TONOIU

Based on experimental research on the static stiffness (own and contact), the paper presents the behaviour of a patented solution of tools for the turning processes, in comparison with the classic solution. The patent has received a gold medal at the International Inventions Convention from Geneva in 1995.

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13

STUDY OF THE CNC LATHE CONTROL PARAMETER INFLUENCE UPON THE CONTOURING ACCURACY

Dumitru DUMITRU, Eugen STRÃJESCU

The influences of the axes servo-parameters and dynamics on the contouring accuracy at the linear interpolation in a system with two numerical axes, typical to CNC lathes, are studied in this paper.\r\nFor this, a simplified model of the lathe feed system is proposed, where the mechanical structure and the main servo-p…

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14

ABOUT THE STATIC BEHAVIOUR OF ELECTRO-DISCHARGE MACHINE

Laurenþiu BÃLUÞÃ, Traian AURITE

The structural elements of electro-discharge machines are similar with the classic machine tools structural elements (milling machine, drilling machine, etc.), but studying their behaviour was not approached in the same way. Taking into account the details of processing by electro-discharge machining, knowledge of the …

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15

EFFETS DES RISQUES LIES À LA CONCEPTION DE PRODUITS INNOVANTS

Elena-Loredana PODEA, Severine SPERANDIO, Philippe GIRARD Constantin ISPAS

From the creative idea to the adoption of a new product, the risk management does not relate to only strategic level of the company and financial aspects. The company must thus manage the risks throughout process of innovation in order to multiply the chances of the project success. This work deals with the preliminar…

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16

THE WEAR OF GEAR TEETH WITH FUNCTIONALITY IN ABRASIVE RANDOMLY PARTICLES

Monica VLASE, Andrei TUDOR

It is shown that the abrasive particles, which penetrate in the convergent joint of gear’s teeth friction pairs, can damage the superficial layer of surfaces. The wear caused by individual particle depends on having both a satisfactory understanding of individual interactions and a suitable procedure for combining thes…

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17

RECHERCHES SUR LA RÉSOLUTION DES PROBLEMÈS ET LA GESTION DES RISQUES DANS LE PROCESSUS DE CONCEPTION DES PRODUITS

Dana TILINA, Constantin ISPAS, Dragoº TILINA

The study presented aims to optimize the design in two directions. The first direction aims to consider the concept as a set of activities to solve problems and then establish a general model for solving them. The second direction of research has sought to implement a process of risk assessment in the design stages, co…

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18

ECOLOGICAL RISK ASSESSMENT METHODOLOGY BASED ON EVIDENTIAL REASONING THEORY

Mãdãlina ARAMÃ, Adrian V. GHEORGHE, Corneliu V. RADU, Radu D. STANCIU, Margareta NICOLAU

The paper presents o new methodology to be used in Romania at the level of year 2008 regarding the ecological impact/risk assessment based on Dempster rule of combination from Dempster-Shafer evidence theory and the Evidential Reasoning algorithm. This methodology is able to face uncertainty proper for systems involvin…

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19

MIXING PROCESS IN ROTATING MOTIONS

Cãtãlin MÃRCULESCU, Corneliu BÃLAN

The paper is concerned with the investigations of the mixing process generated by a spinning rotor inside an enclosed cylindrical vessel. The aim of the study is to compare experimental results with numerical predictions for a rotating disk and an impeller with the following leading objectives: (i) FLUENT code validati…

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20

MATHEMATICAL MODELING AND NUMERICAL SIMULATION OF SLUDGE THICKENING PROCESSES IN GRAVITATIONAL SLUDGE THICKENERS

Antoniu BEIOGLU, Valeriu PANAITESCU, Dan ROBESCU

The theoretical aspects of sludge movement through the sludge handling equipments have not been solved entirely until now. In the literature, the sludge handling problems (flow and phases separation) have been solved only from the technical point of view. This paper presents the mathematical modeling and numerical simu…

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21

SYSTEMIC APPROACH TO THE INTEGRATED ENVIRONMENTAL MANAGEMENT

Florian GRIGORE, Dan ROBESCU, Vladimir ROJANSCHI

In this work, theoretical and general aspects comprised in the international series of standards ISO 14000 are used in order to highlight the specific elements of a water and sewerage operator and to indicate what should be done by the management of the organization in order to apply those provisions. The safety index …

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