A study of the collapse behaviour of hemi spherical and shallow spherical shells and their modes of deformation under impact loading are presented in this paper. Aluminium spherical shells of various radii and thicknesses were made by spinning. These were subjected to impact loading under a drop hammer and the load histories were obtained in all the cases. Three-dimensional numerical simulations were carried out for all the tested specimen geometries using LS-DYNA®. Material, geometric and contact nonlinearities were incorporated in the analysis. The uni-axial stress-strain curve for the material was obtained experimentally and was assumed to be piecewise linear in the plastic region. The results from impact experiments are used for the validation of the numerical simulations. Three distinct modes of deformation, namely local flattening, inward dimpling and formation of multiple numbers of lobes were analysed and influence of various parameters on these modes is discussed. © 2006 Elsevier Ltd. All rights reserved.

R. Velmurugan

Department of Aerospace Engineering

Aluminum

Buckling

Computer simulation

Deformation

Energy absorption

Impact testing

Nonlinear systems

Stress-strain curves

AXIAL LOAD

DIMPLING

DROP HAMMER IMPACT

FLATTENING

SPHERICAL SHELLS

Shells (structures)

Fulltext

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IIT Madras

International Journal of Solids and Structures

Collapse behaviour of aluminium thin conical frusta with shallow spherical caps (shells of combined geometry) is studied both experimentally and numerically. These shells were of four different thicknesses and were subjected to axial compression between two rigid platens under both quasi-static and impact loading. The R/t values of the spherical portion of the shells were varied between 27 and 218, and for the conical frusta portion, mean diameter-to-thickness (Dm/t) values were varied between 79 and 190. Quasi-static tests were performed on a UTM of 100 T capacity with digital recording facility. Impact experiments were carried out on a drop mass set-up. A three-dimensional non-linear finite element analysis was carried out using LS-DYNA. Numerical results thus obtained were validated with the experimental results. Typical time histories of the specimen deformation and load compression curves were obtained. The behaviour of these shells of combined geometry is compared with the response of the shells of spherical or conical geometries. A discussion on their deformation behaviour, mean buckling load and energy absorbed is presented, and influence thereon of various parameters is discussed. © 2008 Elsevier Ltd. All rights reserved.

International Journal of Impact Engineering

Analysis of collapse behaviour of combined geometry metallic shells under axial impact

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Thin-Walled Structures

Axial compression of metallic spherical shells between rigid plates

The Journal of Strain Analysis for Engineering Design

Spherical shells in inelastic collision with a rigid wall—tentative analysis and recent quasi-static testing

Crushing analysis of rotationally symmetric plastic shells

International Journal of Mechanical Sciences

A theoretical and experimental study of hemispherical shells subjected to axial loads between flat plates

Experimental and numerical investigations into collapse behaviour of thin spherical shells under drop hammer impact

Journal	International Journal of Solids and Structures
ISSN	00207683
Open Access	No