Citation

Wijayathunga N, Webb DC, Kormi K. Int. J. Crashworthiness 2003; 8(1): 53-61.

Copyright

(Copyright © 2003, Informa - Taylor and Francis Group)

DOI

unavailable

PMID

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Abstract

Two separate cases of orthogonal head-on and side impact crash occurrence between thin rectangular, prismatic, nose cone type structure with rigid objects are studied. In the first case, the cone is given an initial velocity of 150 ms(-1) towards a rigid wall, on collision commencement the nose curvatures reverses generating pull on the cone sides which, together with the push induced by its forward motion, initiates sequential fold formation. Because of the 90degrees sharp discontinuities that exist on the adjacent faces, the protrusion type folds on the model side is accompanied by intrusions on the upper surface i.e. manifesting geometrical discontinuities on spines. In the second case, a cylindrical projectile with a hemispherical front carries a mass of 0.709 kg (equal to the mass of the model) and is given a velocity of 75 ms(-1) in orthogonal direction to the side of the model. In this case, when the projectile collides with the model, the impacted side stretches over the projectile nose and deforms inwardly coming into contact with other parts of the model both at the inner and the outer surfaces generating self-contact. In both cases considered the contact mechanical constraint is assumed to be of kinematic type and all zones which are likely to participate in contact formation is incorporated in contact algorithm definitions. In the case of head-on collision, the front crumples and rear end remains relatively undamaged, whereas in the second case, the damage, in spite of reduction of the energy by 75%, is much more substantial and the risk involved is far greater than that of head-on collision. Based on folding, stretching and combined deformation modes a simplified technological concept is developed to support the FE results. In the absence of experimental evidence such theory is of crucial importance to assess the meaningfulness of the computational results.

Language: en