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Showing 2 results for Inelastic Deformation
Hashem Babaei, Tohid Mirzababaie Mostofi, Majid Alitavoli,
Volume 15, Issue 4 (6-2015)
Abstract
The main aim of this paper is to study the inelastic deformation of fully clamped rectangular plates under hydrodynamic loading by low rate with drop-hammer, both experimentally and analytically. In the analytic section, some models are presented for predicting the mid-point deflection by two methods consisting the plastic hinge and energy method. in the plastic hinge method, it is assumed that the used plate in the experimental analysis consists a central hinge and four decentralized hinge inside and also four hinges for fully clamed supported conditions; but in the energy method, the proposed model assumes the deformation in three directions and membrane and bending strain, besides the deformation profile and also the strain rate is assumed. To do this, in experimental section, some experiments were conducted on rectangular plates with different thickness, materials and different levels of energy in order to validate the obtained results from analytic results and also surveying the mechanical behavior of materials according to impacts. By comparing analytic and experimental results, it is obvious that results have satisfying accuracy, therefore using the presented analytic models is desired for predicting the mid-point deflection of rectangular plates under the hydrodynamic loading.
M. Sayah Badkhor, T. Mirzababaie Mostofi, H. Babaei,
Volume 20, Issue 4 (4-2020)
Abstract
In this paper, an experimental and numerical study on the inelastic deformation of fully clamped circular, rectangular and triangular plates under the low-velocity hydrodynamic loads has been conducted using the drop-hammer machine. In the experimental section, steel and aluminum plates with three different geometries of circular, rectangular and triangular in different thicknesses of 1 to 3 mm were examined. Experiments were carried out under different levels of energy by changing the height and mass of the hammer and the maximum permanent transverse deflection was recorded as the test output. For better understanding the effect of effective parameters in these experiments, the Design-Expert software was used. In this software, the simultaneous effect of these parameters was investigated using the response surface method. The plate thickness, the standoff distance of the hammer and the mass of hammer were considered as independent quantitative parameters, and the geometry of the plates along with the material of plates was considered as independent qualitative parameters. The obtained regression model has a confidence level of 95% for output prediction. Accordingly, the p-value for the model is less than 0.05, which means that the regression model is significant. The values of R2 and R2adj was 0.9803 and 0.97131, respectively. The results of the regression model have a good agreement with experimental results. In all experiments, the standoff distance of the hammer was the most effective parameter while the mass of the hammer had the least effect on the response. The optimum conditions for each plate were also determined.
