Study On The Mechanism Of Neutral Layer Offset In Hot Straightening Of Metal Matrix Composite Plate

With the improvement and development of science and technology in China,the requirements for material performance and quality are constantly increasing.Bimetal composite plate is a new composite material and has the advantages of excellent composite performance and low production cost.In the process of production,bimetal composite plates are prone to form defects such as waves,ladles and sickles.It is necessary to straighten the composite plates.In order to improve the straightening accuracy and reduce the cracking of the composite plate after straightening,it is necessary to study the phenomenon of the neutral layer deviation in the straightening process of bimetal composite plate.In this paper,the relationship involved in the deformation process of the plate is expounded and the calculation method of the main parameters such as bending amount,bending moment,straightening force is deduced by using the traditional metal elastic-plastic theory.Meanwhile,the calculation formula of the stress neutral layer offset of the bimetal composite plate is derived according to the bending deformation of the plate.In the micro simulation,the bimetal composite plate is used as the template to determine the law of atomic motion,the material mechanics and the interface binding energy of the material.In the soft of finite element analysis,the straightening process of bimetal composite plate is simulated,the stress change and the neutral layer offset in the straightening process are analyzed,at the same time,the interface binding energy and the plate shape after straightening are determined.The results show that the anisotropy should be considered in the simulation process to improve the straightening accuracy,and the deviation of the neutral layer shifts to the stressed side in the straightening process.Finally,the correctness of the reduction of the composite plate is proved by the experiment to ensure the straightening accuracy,and the phenomenon of the neutral layer deviation in the straightening process of the composite plate is analyzed.Through the comparison of theoretical calculation formula,finite element analysis and experiment,the correctness of theoretical calculation formula is proved,which shows that the phenomenon of neutral layer offset in the straightening process of bimetal composite plate can effectively improve the straightening accuracy and avoid the shape defects.