1.3D modeling system framework based on OpenCascade
WxWidgets is used as the development tool of the system interface and the framework of the whole riser design process. In this framework, firstly, the three-dimensional model of steel castings is imported to calculate the volume, area and outline dimension of steel castings, and then the overall modulus of steel castings is obtained. By setting different types of interceptors and parameterizing the size and position of interceptors, the local modulus of steel castings can be obtained. According to the selected riser type and database, the parameters of riser system can be obtained. After parameterizing the riser position and parameters according to the actual situation, the riser system can be finally applied to steel castings.
2.Riser drawing process of typical steel castings
The OpenCascade platform provides the generation, display and analysis of 2D and 3D geometry. The so-called geometric modeling kernel is actually a class library, which defines the storage format of graphic data and a large number of graphic algorithms.
Although OpenCascade provides an application programming interface (API) to use the classes and algorithms in the library classes, it is cumbersome to use OpenCascade basic functions to design the riser of steel castings in each design process. To solve this problem, the system encapsulates a set of method functions for designing the riser of steel castings through the geometric modeling function algorithm and class extraction and redesign in OpenCascade. This method can directly design the riser of steel castings, and a standard riser model of steel castings can be obtained only by selecting the riser type of steel castings. Next, taking the geometric modeling of waist circular steel casting riser as an example, the drawing process of steel casting riser is explained. The main process of this process is as follows: the sketch object of the waist circle is obtained through the basic method function of OpenCascade, then the waist circle sketch is converted into a face object through the “line surface conversion” function, and then the waist circle surface is stretched into a cylinder through the stretching function. Finally, the face rounding transformation is performed by selecting the edge of the bottom surface of the cylinder, and finally the purpose of generating the riser of the waist circle steel casting is achieved. In this process, the parametric driving of each construction process can be realized, which lays a foundation for the independent development of the steel casting riser system matching the database.