说明：  给出了约束因子的扩展模型、带约束因子变密度法的改进数学模型以及带约束因子变密度优化设计的求解过程和应用流程图,并用MATLAB程序实现该算法。通过一个算例计算给出了求解运算和数据分析结果,验证了该方法求解的可行性与有效性。
(The extended model of constraint factors, the improved mathematical model of the constrained variable density method and the solving process and application flow chart of constrained variable density optimization design are given, and the algorithm is implemented by MATLAB program. The results of the calculation and data analysis are given by an example, and the feasibility and effectiveness of the method are verified.)