He, Xu (Wuhan University of Technology) | Zhu, Ling (Wuhan University of Technology) | Chen, F. L. (Institute of Applied Physics and Computational Mathematics) | Li, Xiaobin (Wuhan University of Technology) | Liu, Jianhua (Marine Design & Research Institute of China)
This paper studies the relationship of the saturated impulse between square plates made of steels with various yield stresses. Material of square plates is assumed to be elastic, perfectly plastic. Finite element (FE) code ABAQUS is employed to simulate the elastoplastic response of plates under uniform rectangular pressure pulse. The quantitative relationships of the saturated permanent deflection and the saturated loading duration for the maximum deflection between various yield stress-steel plates are obtained, in which the plates have the same size and are under the same magnitude of loading. For different steel square plates with various yield stresses under a pressure amplitude, provided a rupture failure does not occur the ratio of their saturated permanent deflection approximately equals the reciprocal of the ratio of their yield stresses; the ratio of their saturated loading duration for the maximum deflection approximately equals the reciprocal of the square root of the ratio of their yield stresses. The expression forms of the dimensionless saturated permanent deflection and the dimensionless saturated impulse for the maximum deflection of a square plate are proposed. The dimensionless saturated permanent deflection is a power function of the dimensionless pressure amplitude. The dimensionless saturated impulse for the maximum deflection is linearly related to the dimensionless pressure amplitude. Some fitting formulae for the deflection and saturated impulse are proposed. Finally, an estimation of the dimensionless pressure amplitude for the onset of failure Mode 2 indentified by Menkes and Opat (1973) for a square plate by using a rigid-plastic procedure is made and its comparison with prediction from elastoplastic finite element model (FEM) is satisfactory.
The design process for structures often requires an estimate of the response for large dynamic loadings arising from impact and/or explosive events so that many efforts have been focused on the analysis of dynamically loaded structural elements. Saturated impulse phenomenon is a characteristic of the response of plates subjected to a pulse loading when large inelastic deformation occurs. The concept is that if a plate is subjected to a rectangular pressure pulse with a sufficiently long duration, then only an early part of the pulse contributes to the maximum and permanent deflections of the plate, and the rest of the loading pulse will cause no further increase of these deflections.