大型飞机总装配中支撑点设计分析技术

当采用多个数控定位器对飞机机身进行支撑和定位时,由于重力载荷等因素的影响,机身会产生变形,而机身的变形可能导致装配过程中对机身制造和装配准确度的误判.为了保障飞机的整机装配质量,需要给出合理的机身支撑点数量和位置.根据某大型飞机的全机对接装配问题,建立机身的有限元模型,研究了不同支撑条件下飞机的变形性态,分析了定位器的数量、布局以及工艺接头的安装位置等因素对机身变形的影响,结果表明：当机身姿态角度参数由0°变化到10°时,机身测量点平均误差值由0.641 0 mm变为0.910 0 mm,而测量点最大误差值变化并不明显;当工艺接头安装角度由 0°变化到15°时,机身测量点平均误差值由0.910 0 mm变为1.216 2 mm,测量点最大误差值由2.803 4 mm变为3.122 9 mm；机身分别采用三点支撑（1、2号支撑框位）,四点支撑（1、3号支撑框位）和六点支撑时,测量点平均位置误差分别为1.567 6、0.690 0、0.458 1 mm,测量点最大空间位置误差分别为2.738 8、1.228 1、0.874 9 mm,根据计算结果和机身装配工艺要求,最终确定机身采用六点支撑.

Design and analysis of fuselage supporting position for aircraft final assembly

The number and layout of positioners should be designed reasonably to avoid misjudgment of fuselage manufacturing and assembly accuracy and guarantee the fuselage assembly quality. Based on the final assembly system of one certain large aircraft, a finite element model of the fuselage was established. Under different supporting conditions, the factors was influencing the fuselage deformation were identified and analyzed, such as the number and layout of positioners, and the mounting location of joint. The results showed that with the posture angle parameter changed from 0°to 10°, the average position error of measuring points changed from 0.641 to 0.910 mm, whereas the maximum position error of measuring points did not significantly change. With the installation angle of joint changed from 0°to 15°, the average position error of measuring points changed from 0.910 to 1.216 mm, and the maximum position error of measuring points changed from 2.803 to 3.129 mm. When the fuselage was supported by 3 positioners, 4 positioners and 6 positioners, the average position error of measuring points was 1.567，0.690 and 0.458 mm respectively, and the maximum position error of measuring points was 2.738，1.228 and 0.874 mm respectively. To fulfill the requirement of fuselage assembly technics, the fuselage should be supported by 6 positioners according to the fuselage deformation conditions.