On the Study of Automatic Plate Bending

人们常说，造船业的主要特点是船舶是由大尺寸的焊接结构组成的，而且其结构，特别是船头和船尾部分，是由自由曲面组成的。因此，板材弯曲是船舶生产过程中最重要的工艺之一。为此，采用远线加热法对具有双曲度的板材进行弯曲。然而，要实现造船自动化，板材弯曲工艺是最复杂的，在造船行业中，开发自动化弯板设备一直是一个梦想。(1)研制了一台使用6x6活塞(总重20吨)的自动弯板装置样机。(2)为了了解该设施的性能，对100多块钢板进行了试验。(3)为了了解工作面的设计形状与板的嵌入形状之间的关系，开发了基于有限元的计算程序NCBEND。利用NCBEND程序，可以方便地计算板在弹塑性状态下的有限变形问题。(4)将试验结果与计算结果进行比较，初步建立了曲面嵌套形状的估算方法。

It is often said that the main characteristics in shipbuilding industry are ship is composed of a large size of welded structures and also her structure, especially at fore and aft parts, is composed of free curved surfaces. Therefore plate bending is one of the most important techinique in ship production stage.Thus far line heating method is employed to bend a plate which has double curvatures. In order to make automated shipyard, however, plate bending process is the most complicated one.In shipbuilding industry, the development of automatic plagte bending facility has long been a dream. However, there were few study in the world In this paper, (1) A prototype of automatic plate bending facility is developed, in which 6x6 pistons are used (total load 20 ton). (2) In order to know the capability of the facility, more than a hundred of steel plates are tested. (3) To know the relation between design shape of face and set-in shape of plate, a calculation program called NCBEND based on finite element method is developed. By using the program NCBEND, a finite deformation problem of plate bending in the elastic-plastic stated can easily be calculated. (4) Comparing test results and calculated ones, a estimation method of set-in shape of surface is generally established.