The Study And Development On The CAD System Of Abnormal Stone

The paper researches the characters of the abnormal stone and the prime design principle of CAD system. The author has the quadratic development with the help of the new AutoCAD software. The system has developed CAD system to stone spiry-stair baluster with the technology of Object Oriented Programming and parametrical method in Visual Basic. The system is advanced on theoretical and practical parts and provides a friendly interface. It raises the design efficiency and reduces the cost.The paper has made the interacting design to the cover board and lateral board of the stone spiry-stair baluster. Based on AutoCAD system, the cover board and lateral board of the stone spiry-stair baluster are designed parametrically using the programme. Main contents are discussed in this thesis as follows:Firstly, the convenient and applied error formula and the whole dimension calculation which are produced by making the helicoid of cover board in several different ways, the technics is deduced in the method of differential geometry, based on the gived error, the parametrical division and serial numbers.Secondly, the cover board and lateral board of the stone spiry-stair baluster must be divided and made sequence numbers, so the paper gives the approximate processing method of choosing to use the separate plane and columnar section to replace the helicoid. It makes the helicoid can be divided automatically, the maximal error must be less than the allowable error. Every piece can be gived the number after division in semiautomatic method.Thirdly, the parametrical plot to the cover board and lateral board is made, the user runs the programme at first, then fills in the concrete parameters in the parametrical sheets, and connects to the AutoCAD system and draws the corresponding graphs of the cover board and lateral board in the active page.