Analysis of elastic-plastic steel plates forming based on typical shipyard's roller bending machine

Abstract Steel plates forming process, as an important component of the ship production process, is presented in this paper with the main intention to address the influence of different assumed stress-strain relationships to the analysis of the elastic-plastic forming process, particularly regarding bending moments, bending forces and energy required to achieve desired steel plate plastic deformations. Applicability of the simplified, one-dimensional analytical models and different stress-strain relationships is successfully verified against the experiment as well as by comparing the obtained results to more complex 2D plate theory in cases of four different steel grades (S235, S355, S420, S460) for the plate thicknesses up to 50 mm. Influence of bending radius, the distance between rollers and roller radius is analyzed further on and aspects of plate spring-back effects, i.e. residual stress, and permanent curvature, are addressed. Finally, the importance of the present research in cases of ship production and ship structural analysis and design is pointed out.