Research On The Forming Process For Aircraft Structural Reinforce Panel

The reinforce panel was an important part of the aircraft structure system and an important assurance for aircraft flight safety. At present, the reinforce panel was still processed by drop hammer, which was a traditional forming technology. The disadvantages of the traditional method were low efficiency, high rejection rate and low accuracy of parts.In the paper, aiming at the characteristics of the reinforce panel and the disadvantages of the traditional forming technology, finite element simulation was applied to systematically conduct technical research on aircraft structure reinforce panel. Finally, two technologies were proposed including hydraulic forming and rigid-mould drawing forming and the feasibility of these two technologies was testified. At last, the aviation industry standard HB6470-1990 was referenced to check the quality of part.For hydraulic forming technology, the results showed that the fillet radius of part was more than 3mm after processing due to the specialty of part structure, and then another fabrication procedure should be added. After the whole process, the thinning ratio of part was 33.25%. It meant that the probability of crack was very high.For rigid-mould drawing forming technology, single drawing forming and multi-pass drawing forming were proposed. Simulation results showed that the thinning ratio of part was 30% and the low thinning ratio of part might lead to crack at the end of single drawing forming. While for multi-pass drawing forming technology, the additional mould, which kept the original type of part and increased the fillet radius and the depth of drawing, was added in the forming course. Then the final part would be formed with designed stage mould after twice drawing forming. At the end of multi-pass drawing forming, the thinning ratio of part was 27.12%, which met the requirement of the aviation industry standard. Consequently, the multi-pass drawing forming process could ensure the quality of part.In the paper, the influences of technological parameter and open cutting on quality of forming part were studied by stimulating, and then the process parameters were optimized, which provided an effective theoretical basis for the actual production process.