Assembly Accuracy Analysis of Small Deformation of Flexible Body based on Differential Transformation

Rigid body assumptions were usually used as the premise for assembly accuracy analysis during the product design stage, and the effects of load factors such as external loads and temperature changes were often ignored. In the case of manufacturing errors and assembly errors, the deformation of the part caused by the load factor would further affect the assembly accuracy. Therefore, an assembly accuracy analysis model that considered manufacturing , assembly errors, and part deformations simultaneously was proposed. Firstly, the model made the deformed Tolerance Features discretized along the dimensional chain, and established and consolidated the node coordinate system at each node. Then, the node's deformation information was extracted and differential transformation on each node coordinate system on the target feature was performed to achieve the error synthesis with deformation. Finally, a linearized comprehensive error analysis model was established. The results show that the model overcomes the limitations of the traditional error analysis model based on the assumption of rigid bodies, obtains the effect of the local deformation of parts on assembly accuracy, and also greatly reduce the difficulties and workload of geometric modeling and mechanical analysis.