ABSTRACT
Modern aircraft skin materials are usually of highstrength aluminum alloy, carbon fiber reinforced aluminum alloy composites and other composite materials, and has the characteristics of big structure size, poor rigidity, and high positioning accuracy requirements. Because the aircraft skin is in the form of thin-walled open surfaces and the entire part is in a flexible form of state, the clamping assembly process is difficult and it often requires the fixture design department to design more fixture system to assemble. The traditional six-point positioning principle is not suitable for this type of thin elastic stiffness and poor surface profile of freeform parts[1], as it seriously affects the quality and efficiency of assembly. Therefore, under the conditions of the elastomeric surface positioning, the aircraft skin should be in contact with the surface in tooling. The finite deformation is a guiding principle which cannot be ignored in clamping system designing and analyzing[2], to rationally determine the size of the clamping force and the position of points, in order to make the aircraft skin small deformation, thereby to enhance the accuracy of the entire aircraft skin assembly. Therefore, the clamping system should ensure the accurate positioning of aircraft skin, maintain the stability of aircraft skin, in order to control the aircraft skin deformation within a certain range.
