铝锂合金自动铆接干涉量及残余应力分析

Analysis of Al-Li Alloy Interference and Residual Stress after Automatic Riveting

摘要:

摘 要: 铝锂合金是航空制造中的新型合金材料，其铆接技术是现代飞机制造重要研究方向。铆接后的铝锂合金板孔的干涉量影响到残余应力分布，为了研究铆接过程与残余应力分布特征之间的关系，利用自动钻铆装备对不同厚度的铝锂合金板进行铆接。使用ABAQUS/Explicit对铝锂合金自动压铆过程进行了仿真，通过试验和仿真的方法分析不同压铆力、铆钉长度、壁板厚度和铆钉材料等组合条件下铝锂合金壁板内部所产生的干涉量，进而推导出各工艺条件下铝锂合金壁板厚度方向上残余应力的分布规律。研究结果表明，2060-T8铝锂合金壁板孔壁产生的干涉量及沿板厚方向分布的残余应力随压铆力的增大而增大，随铆钉长度的增大而减小，随壁板厚度的增加呈现非单调增长的趋势。壁板总厚度为4.2mm时，平均干涉量及平均残余应力可以达到最大值。相比于2117-T4铝合金铆钉，采用7050-T3铝合金铆钉压铆后2060-T8铝锂合金壁板产生的平均干涉量降低6%~12%，平均残余应力降低8%~12%。

Abstract:

Abstract: Al-Li alloy is a new alloy material used in aviation manufacturing. The riveting technology of Al-Li alloy is an important research direction of modern aircraft manufacturing. The distribution of residual stress after riveting is affected by the amount of interference in the hole of Al-Li alloy sheets. The automatic dirlling and riveting equipment was used to rivet Al-Li alloy sheets of different thickness for the purpose of researching the relationship between riveting process and residual stress distribution. The automatic riveting process of Al-Li alloy was simulated by ABAQUS/Explicit, the interference amount generated in Al-Li alloy wall under different riveting force, rivet length, the thickness of sheets and rivet material was analyzed by experiment and simulation. Then the residual stress distribution characteristics along the thickness direction of Al-Li alloy sheet under various conditions was deduced. The resules indicate that the interference produced in the hole wall of Al-Li alloy sheets and the residual stress have the highly consistent tendency under various technological conditions. The specific trends are as follows, in which the interference and residual stress increase with the argument of the riveting force. However, they will decrease with the increase of the rivet length. As the total thickness of the sheet is increasing, the average interference amount and the average residual stress increase in the beginning and then decrease. When the total thickness of the sheet is 4.2mm, the interference and residual stress arrive at the peak value. In addition, the average interference amount produced by 7050-T73 aluminum alloy rivets is reduced by 6%~12% compared to the 2117-T4 aluminum alloy rivets. And the residual stress is reduced by 8%~12%.