Research On Fixture Optimization Of The Thin-walled Parts Based On The Composite Error Control

The complex and thin-walled parts are widely used in aerospace industry. Deformation will easily be caused during the machining process because of its poor rigidity. The research is supported by the National 863 project:The study of precision control methods of complexe and multi-process thin-walled parts based on composite error analysis. The fixture optimization method is studied around the project.The prototype of the fixture optimization system is built through the analysis of the current contents and characteristics of computer-aided fixture design. Fixture optimization will be done after the geometric information, process information and the precision information is input to the system, then we can get the result of the fixture structure.One of the factors of processing error is the locating error. The meaning of location optimization could be seen by analyzing how the location layout impacting the location error. As we know, we can connect the three location point on the main location area to be a triangle. The locating optimization method is presented according to two principals:maximize the area of the triangle and the summation of the distance that the barycenter to the edge of the triangle. This paper also establishes the locating optimization process. The location optimization method is implemented by the parameterized finite element model with the ANSYS Parametric Design Language.A fixture-workpiece-tool system is established to study how the clamping sequence and processing sequence impacting the deformation of the thin-walled parts. A general method which can determine the optimal clamping sequence and processing sequence for complex and thin-walled parts is obtained.