Measurement and prediction of deformation in plane strain compression tests of AA5182

Abstract

The present paper concerns the numerical prediction and experimental measurement of the distribution of strain in a plane strain compression test by means of a gridded insert. The insert was engraved with a 1 × 1 mm grid pitch and was embedded in an AA5182 sample. The tests were performed at 400°C with a reduction ratio of ∼20% and at a strain rate of 0·7 s⁻¹. A thermocouple was used to record the temperature during the test. After the test, no detachment was observed between insert and sample, suggesting a close contact between them. The shape of the grid after deformation was analysed, and the in-plane component of the plastic strain calculated and compared with the numerical results obtained through finite element modelling of the test. In a comparison between experimental data and the results of a finite element (FE) model of the test that assumed perfect tool alignment, the fields of temperature agreed very well, while that for the in-plane component of strain was reasonable but inaccurate. However, significant misalignment of the tools was found in the experiments (a common occurrence in plane strain compression testing). When comparison was made with an FE model that included the geometry of the tool misalignment, the agreement was excellent. The paper discusses these effects and others such as the influence of 3D effects in the modelling.