On the Deformation of a Plastic Column under Axial Impact

Abstract

In this paper the distribution of the stress and strain along the long plastic column under axial shock type load were investigated theoretically with some aid of experiments using plastic material such lead bar. In this theoretcial calculation, following assumptions have been used in the relation between dynamical stress and strain when the column is subjected to the axial shock type load: 1. The impact stress is represents by the sum of the stress proportional to the strain and the stress proportional to the straining speed wh ch produced by the impact, and the relat ons are preserves up to the column has buckled. 2. The elastic deformation is of little importance compared to the plastic deformatoin. The results obtained by the investgations are as follows: 1. The mode of the plastic deformation and the stress destribut on along the column under axial impact have been shown by hyperbolic express ons.2. Additional stress proportional to the straining speed has been obtained as the coefficient of viscosity in the plastic range. 3. The ratio of shock type stress and strain which correspond to the Young's modulus were obtained as the parameters of straining speed of the element of the column, 4. The stress strdin diagram in the case of impact loading were obtained as the transition curve across a point of different stress-strain curves which obtained as the parameter of straining speed.