大型飞机机身双曲度蒙皮纵向拉伸成形加载优化设计与试验研究

目的针对C919大型客机机身双曲度蒙皮进行纵向拉形的加载轨迹优化与试验研究。方法应用蒙皮拉形工艺设计制造软件,采用优化设计的方法,对机身典型蒙皮零件进行纵向拉形加载轨迹设计;进行拉形过程的有限元仿真,判断设计的加载轨迹是否满足成形要求,将优化后的加载轨迹应用于实际零件成形;进行实际零件拉形试验,对毛料伸长与局部应变进行测量,与有限元仿真进行对比,验证有限元仿真的准确性。结果实际零件的毛料伸长与轨迹设计和有限元模拟的伸长量十分接近;将优化设计后的加载轨迹应用于实际零件的成形,获得了满足零件交付要求的蒙皮零件。结论通过加载优化设计与试验,验证了有限元模拟有较好的精度;通过加载轨迹优化与有限元模拟结合的拉形工艺设计方法,可以用于零件的实际生产。

Optimization Design and Experimental Study on Loading Path of Longitude Stretch Forming for Double-curved Fuselage Skin of Large Aircraft

Objective To study the optimization design method and production experiment on the longitude stretch forming loading path for double-curved fuselage skin of large aircraft. Methods Appling the optimal design method, The loading path of longitude stretch forming for double-curved fuselage skin of large aircraft has been optimized with XSTR Stretch software. The stretch process is simulated with FEM to evaluate the designed loading path. The optimized loading path has applied directly for the actual part forming. The elongation and local strain of the blank is measured after the actual part stretch forming test and measurements compare with the FEM simulation to verify the accuracy of FEM. Results The elongation of actual forming part and FEM simulation is proximity and acceptable. The fuselage skin which meets the delivery requirement has been obtained after applying the optimized loading path. Conclusion The accuracy of FEM is verified by the lading path design and actual part forming tests. The design method combined with optimized method and FEM simulation is capable for applying to actual part fabrication.