Abstract: As a part of systematic study on non-rotational symmetrical drawing, flow displacement and law of materials of blank holder face and case bottom are analyzed according to the measurement of grid strain in rectangular case drawing. Comparing to strain in a cylinderic drawing, the greatest differences include: the compressive strain of circumferential direction in a flange is not proportional to its tensile strain of radial direction, and flow strain in a corner section is non-continuous, and the plastic flow opposite direction of drawing loaded is produced at a short axis of case bottom and other strain circumstances. All these results are key points, which should be undersood and mastered, to do the calculation with the finite element method. Furthermore, these results also indicate that the forming limit of drawing for larger cover parts could be improved if local lubrication is suitably and reasonably carried out according to the law of materials flow.

Key words: Circumferential compressive, Plastic flow, Radial stretching, Rectangular case drawing, Passengers, Form Design, Train Interior, Visual Images