Numerical Simulation And Experimental Verification Of Two-Layered Tube Bending

With the rapid development of manufacture technology, tubes have been widely uesd to manufacture products applied in aerospace, engineering machinery, power plants, agricultural machinery ,oil industry, transpotation etc. For this reason, tube forming technology has become very important in modern manufacture industry. Tube forming technology is such a processing technology that reprocesses tubes to manufacture parts. Tube bending is the most commonly used technology of tube forming.Two-layered metal tubes are made of two or more kinds of materials, which have many advantages, such as saving rare elements, higher performance to price ratio etc. In recent years, they have been developed and used in industry and daily life. So the research on two-layered tubes bending is becoming very important and meaningful.The main contents of this paper are as follows: 1. The materials parameters are obtained by material test, the commercial FEA software, DYNAFORM is used to simulate the tube bending process, the simulation results of thickness, strain and stress distribution are obtained, and forming defects are predicted.2. A set of bending mould is designed, reasons of the defects such as wrinkle, burst and cross-section distortion are analyzed, and the simulation results are verified.Numerical simulation and experimental investigation confirm that: single-layered tube bending theory can also be applied to two-layered tube bending; good lubrication condition is good for tube forming quality; forming quality is better in case of bigger bending radius and smaller bending angle ; with effective support inside the bending tube, wrinkle and cross-section distortion could be reduced or even avoided.