| With the rapid innovation of computer technology and the continuous advancement of global industrialization,CAD software is booming and becoming an indispensable tool in the process of industrial production.Yet CAD software market is totally occupied by a foreign commercial software and even monopoly,small and medium-sized enterprises need to pay the foreign manufacturers to purchase a complete set of software and the use of high cost,make use of the software costs increase,the development of a lightweight CAD software may provides a new way for small and medium enterprises,will also help in the strategy implementation of the "made in China 2025".In this paper,a small CAD software system is developed based on the graphical user interface framework Qt and geometry development engine OpenCASCADE.The main work contents are as follows:The two external dependencies of graphical user interface framework QT and geometric development engine OpenCASCADE are deeply studied.The basic functional modules and signal and slot mechanism commonly used in QT are introduced in detail,as well as the basic contents and functions of seven modules of OpenCASCADE.The advantages of using QT and OpenCASCADE for software development are analyzed.On this basis,Qt is used to develop the interface and various window parts of the software,and based on the MVC pattern and Qt signal and slot mechanism to build the software architecture.Based on OpenCASCADE,the basic modeling functions of the software are realized,including parameterized construction of geometric primitive,interactive construction of geometric model,modification operation of geometric entity,space transformation operation,Boolean operation,etc.In addition,the basic type parameters and format of standard bearings were defined.On the basis of geometric modeling,the parameterized modeling operation of ball bearings,cylindrical bearings and tapered bearings was completed by reading data from Excel.Further study of synchronous invocation of the file to read and write methods and the principle of asynchronous invocation method and implementation process,expounds the advantages of asynchronous invocation method,based on the asynchronous invocation method implements the file read and write operations,with examples shows the software file reading speed advantage,commonly used step by reading and writing,iges,STL file for data exchange with other CAD systems.In addition,simple geometric cleaning functions,such as surface suture and fillet removal,are implemented to meet the requirements of CAE analysis. |
