Distribution of stresses due to hydraulic loading in the skin plate of a vertical lift gate: cylindrical shell and flat type (Part II)
14 December 2011
In Part I of this paper the authors modified a conventional vertical lift gate with a flat skin plate, with the cylindrical shell skin plate having vertical stiffeners[2]. However, it was observed that with the increase of sag-to-span ratio the maximum span stress reduces, while the maximum support stress adjacent to the area near the vertical stiffeners increases. To overcome this problem, a modified cylindrical shell skin plate without vertical stiffeners is proposed in this paper. It is observed that the maximum stresses at span, as well as at the end carriage support, decrease in accordance with an increase of sag-to-span ratio. The sag-to-span ratio is determined where the maximum span stress and support stress are equal. Stress and deflection analysis has also been carried out based on the Finite Element Method (FEM), in order to compare the stress distribution in both a flat and cylindrical shell skin plate, with and without vertical stiffeners, and varying sag-to-span ratio.
