| Aircraft pylon emergency breaking away fuse pin for the protection of aircraft body structure has a very important role in the safety,not only protect the normal operation of the engine,but also isolated the engine fire area.The key technology of aircraft pylon emergency breaking away fuse pin is disengagement technology.Its design idea is to pre-design the destruction path of components to limit the transmission of faults and to minimize the damage of aircraft accident.This requires the fuse pins have a very strict bearing capacity,so the study of fracture mechanism on the aircraft fuse pin has become very meaningful.15-5PH stainless steel as an fuse pin material,has a good processing performance,excellent mechanical properties,has good toughness and ductility,hardness and corrosion resistance,so in the aerospace,aircraft parts have a wide range of applications.In this paper,the fracture mechanism of the 15-5PH stainless steel material is studied by the combination of finite element simulation and experiment.First of all,this paper uses the Gleeble 3800 thermal simulation test machine to experiment the 15-5PH stainless steel specimens at room temperature,and obtain the true stress-strain curve of 15-5PH stainless steel under the strain rate 0.01s-1.Based on the elastoplastic constitutive relation,the material constitutive model is established by using Origin software,which provides a theoretical basis for further research on the material properties.Secondly,The shear strength and maximum applied load of 15-5PH stainless steel bar was obtained through shearing experiment by universal testing machine,which was made of 15-5PH stainless steel.ABAQUS software was used to simulate the shear process of the bar material,Studied the shear strength,strain and maximum load of 15-5PH stainless steel bar,and compared with the shear experiment data to verify the accuracy of finite element simulation analysis.According to the shear experiment of the real structure fuse pin,the maximum applied load and the axial displacement of the lower scissor are obtained.In ABAQUS software,established the finite element model of the real structure,and carried out the finite element simulation analysis.The shear stress,strain,the axial displacement of the lower scissors and the maximum applied load are analyzed and compared with the experimental of the real structure of the fuse pin to verify the rationality of the finite element simulation of the real structure of the fuse pin,and on the basis,the change rule of the different inner diameter of the fuse pin is studied.Finally,through the SHPB experiment,the real stress-strain curves under four kinds of high strain rate were obtained,and analyzed the change trend of the four real stressstrain curves,and fitting of four true stress-strain curves to Johnson-Cook constitutive model,and on the basis of this study,the dynamic shear properties of the fuse pin at different strain rates are studied. |
