Experimental and numerical penetration response of laser-welded stiffened panels

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Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2018-04-01

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en

Pages

15

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International Journal of Impact Engineering, Volume 114, pp. 78-92

Abstract

Ductile fracture in large structures is often resolved with non-linear finite element (FE) simulations employing structural shell elements which are larger than localization zone. This makes solution element size dependent and calibration of material parameters complex. Therefore, the paper explores the ability of numerical simulations to capture the penetration resistance of stiffened panels after determining steel material fracture ductility at different stress states. The numerical simulations are compared with experiments performed with rigidly fixed 1.2 m square panels penetrated with half-sphere indenter until fracture took place. Response of the panels was measured in terms of indentation force versus indenter displacement. In parallel, tensile tests were performed with four different flat specimens extracted from the face sheet of panels to characterize the material fracture ductility at different stress states. Panel simulations were performed with two fracture criteria: one calibrated based on the test data from dog-bone specimen and other calibrated based on the data from all tensile tests. To evaluate the fracture criteria in terms of their capacity to handle mesh size variations, mesh size was varied from fine to coarse. Results suggest that fracture criterion calibrated based on the range of stress states can handle mesh size variations more effectively as displacement to fracture showed considerably weaker mesh size dependence.

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Keywords

Ductile fracture, Fracture simulations, Panel indentation, Stiffened panel, Tensile testing

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Citation

Kõrgesaar, M, Romanoff, J, Remes, H & Palokangas, P 2018, ' Experimental and numerical penetration response of laser-welded stiffened panels ', International Journal of Impact Engineering, vol. 114, pp. 78-92 . https://doi.org/10.1016/j.ijimpeng.2017.12.014