Papers by Author: Gheorghe Popescu

Abstract: In this work the authors present the result of the theoretical researches and experiences concerning the identification and elimination of the tight places in the automatic montage of the electric ignition devices used in the pyrotechnic industry for improving the labour productivity. Taking into account the fact the above production system is an expectation system depending on a theoretical study followed by computer simulation with the data processing product WINQSB, Queing System Simulation module, we identified the tight places that generate expectation queues when remaking, verifying and assembling the electric ignition devices of the indigenous electric detonators. In this way, using the WINQSB simulation, we offered solutions for 3 analysis types: the ensemble and marks analysis which entered the system, the analysis of the working machines using and the analysis of the queues.

Abstract: The work relates to practical conceivement and achievement of mecanical and action structure of an antropomorphe industrial robot with 4 freedom degrees + gripper, conceived at “C. Brâncuşi” University – Târgu Jiu for didactical usage. The work presents cinematical chain and building solutions used for mechanical structures, actionand comand systems and speed regulate system of an industrial robot.

Abstract: Fretting is now fully identified as a small amplitude oscillatory motion which induces a harmonic tangential force between two surfaces in contact. It is related to three main loadings, i.e. fretting-wear, fretting-fatigue and fretting corrosion. Fretting regimes were first mapped by Vingsbo. In a similar way, three fretting regimes will be considered: stick regime, slip regime and mixed regime. The mixed regime was made up of initial gross slip followed by partial slip condition after a few hundred cycles. Obviously the partial slip transition develops the highest stress levels which can induce fatigue crack nucleation depending on the fatigue properties of the two contacting first bodies. Therefore prediction of the frontier between partial slip and gross slip is required.