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The static and dynamic compressive behaviour of selected aluminium alloys

Winzer R., Glinicka A.

Engineering Transactions

2011

Vol. 59, iss. 3

85-100

The mechanical properties of structural aluminium alloys EN AW-5083 and EN AW-6082 in the ‘H111’ and ‘T6’ conditions, respectively, subjected to compressive loadings in the quasi- static and dynamic strain rate regimes, are investigated. Both alloys are used as structural components not only in car body design or ship building, but also in civil engineering. Therefore, compression tests at room temperature were conducted using a servohydraulic Instron machine, in order to determine the materials‘ behaviour at low and intermediate rates of deformation. In addition, to predict the dynamic response of these materials, the Split Hopkinson Pressure Bar (SHPB) technique was utilized. For alloy 5083-H111, a changeover from negative to positive strain rate sensitivity at dynamic strain rates is observable, whilst alloy 6082-T6 exhibits a mild trend towards positive strain-rate sensitivity. Furthermore, the coefficients of the Johnson-Cook model, that are valid under dynamic conditions, are determined. The finite element simulation of SHPB experiments shows that the constitutive model represents the materials behaviour quite well.

Observations of the portevin-le chatelier effect via an optical measuring technique

Winzer R., Ajdukiewicz C., Glinicka A.

Logistyka

2009

nr 6

CD-CD

An experimental investigation of the Portevin-Le Chatelier (PLC) effect in the aluminium alloy EN-AW 5083 in the ‘H111’ condition is undertaken in this study. Measurements based on an optical technique, namely digital image correlation are used to specify the spatio-temporal features of the PLC effect. The measurement system that was used is referred to as Aramis marketed by the company GOM. Irregular oscillatory plastic flow and strain staircase behaviour is observed in all tests. This irregular plastic flow represents a material instability resulting in inhomogeneous deformation. The goal of the present paper is to visualize the nucleation and propagation of PLC bands during the process of deformation.

Niniejsza praca opisuje badania doświadczalne nad efektem Portevina-Le Chatelieriego (PLC) w stopie aluminiowym EN-AW 5083 w stanie utwardzenia 'H111'. W celu wyszczególnienia czasoprzestrzennych cech efektu PLC, zastosowano optyczny system pomiarowy. Korzystano z systemu pomiarowego Aramis, opracowanego przez firmę GOM. W każdej próbie zaobserwowano nieregularne oscylacyjne plastyczne płynięcie materiału oraz efekt schodkowania odkształceń. Wyżej wymienione nieregularne płynięcie reprezentuje niestabilność materiałową na skutek niejednorodnych deformacji. Celem niniejszej pracy jest określenie i wizualizacja zarodkowania oraz propagacji linii PLC w trakcie procesu deformacji.