Expansion method for contour line of bulbous bow

Abstract

The invention provides an expansion method for a contour line of a bulbous bow. The expansion method specifically comprises the following steps: S1, sequentially drawing distances from various points to a baseline on a middle longitudinal section plan of the bulbous bow onto a shell expansion plan, expanding transverse curvature and not expanding longitudinal curvature of a bulb in a shell expansion way, and smoothly connecting the various points on the shell expansion plan to form an expanded outer contour line of the bulb; S2, determining an inflection point between the bulb and a shell which is adjacent to the bulb, wherein the inflection point is one point at the top of the bulb; S3, for the shell bow contour line above the inflection point on the shell expansion plan, by taking the contour line above the inflection point of the bow contour line in the middle longitudinal section plan as reference, further expanding other shell parts according to the principle of only expanding the transverse curvature and not expanding the longitudinal curvature. By adopting the expansion method provided by the invention, the bulb and the adjacent shell structure can be correctly expanded, and the shape and the size of the shell can be truly reflected, thereby being conductive to determining the specification of the shell; meanwhile, typesetting, lofting, nesting and processing of the shell in the late stage are guided.

Description

technical field [0001] The invention relates to a method for developing a bulbous bow outline. Background technique [0002] According to the "Ship Structure Drawing" published by Harbin Engineering University in November 1995, on page 134 of the 6th printed edition in March 2005, the content about drawing the fore and aft contour lines is described: since the expansion diagram of the outer plate does not expand vertically, Only the transverse curvature is developed, and the shape of the head and tail contours in the expanded diagram of the outer plate is the same as that in the molded line diagram, which can be drawn according to the dimensions provided in the molded line diagram. However, with the development of ship design, most of the existing ship types generally contain bulbous bows or stern noses (propeller hubs), so that when the outer plate is unfolded fore and aft outlines, the bulbous nose cannot be faithfully unfolded according to the existing unfolding methods. ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a bulbous nose in order to overcome the defects that the conventional unfolding method in the prior art cannot faithfully unfold the actual shape of the bulbous nose, and cannot correctly guide the layout, lofting, nesting and processing of the outer plate in the later stage. The Unfolding Method of Shaped Bow Contour Line

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