Tuesday, September 26, 2017
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Seminar - "Computational Modelling of Internal Combustion Motorvalves: Thermomechanics, Fatigue and Wear", by Alberto Cardona

Monday, January 30th, 2017. Time: 12h.

Place: O.C. Zienkiewicz Conference Room, C1 Building, UPC Campus Nord, Barcelona.

ABSTRACT

Motorvalves work under very stringent conditions with elevated temperature and very low lubrication and should last for an operative lifetime of up to 10^9 cycles or more; therefore, it is necessary to take account of the fatigue behavior at high temperature of valve materials, produced by the repetitive stress peaks during the closing event in the engine, in order to improve design. Furthermore, the occurrence of wear represents a severe problem for valve designers and manufacturers. The primary cause of wear in this component occurs between the contact surfaces of the valve and the valve seat insert under unlubricated contact conditions. A decrease in the fuels lubricity because of environmental regulations is observed in contact areas, contributing to the wear process.

A series of numerical models has been developed to study the thermomechanics, fatigue and wear of motorvalves, and all of them were validated by experiments. The thermal history, the dynamics of impact, material properties for ultra high cycling fatigue at high temperature, and wear were all validated experimentally and compared to numerical models. Mortar methods were proposed to analyze contact, with a particular modification to take account of wear. A wear testing machine for motorvalves, which reproduces the conditions inside an internal combustion engine, was built to generate wear coefficients to be used in design.

SPEAKER CV

Alberto Cardona, director of CIMEC (Santa Fe, Argentina). Senior Researcher at CONICET and Professor at National University of the Littoral.