Study on the expansion damage problem of TA2 titanium coils
January 09, 2023
Titanium coil shell wall expansion fracture behavior has burst load characteristics factors, but also with the material properties, column shell structure characteristic size and other factors related to the specific structural dimensions of the TA2 Titanium Alloy tube, the analysis of the role of different burst pressure.
The researchers used a combination of finite element and experimental analysis method of Titanium Tube burst expansion damage machine and the factors affecting the study, by analyzing the role of different charge burst load in the ideal titanium tube within the propagation of shock waves, strain and stress state evolution and development of the law, to explore the phenomenon of titanium tube fragmentation, the results show that:
1, different burst pressure TA2 titanium coiled tube damage are with the radial direction of 45 or 135 direction of the shear fracture, but the crack initiation, destruction process is different. In the higher burst pressure, fragmentation cross-section microscopic metallography in the middle of the wall thickness can be seen in the distribution of holes and microcrack bands, cracks formed from the middle of the specimen cross-section to the inner and outer surfaces of the extension of the fracture; and in the lower burst pressure, cracks from the specimen at the inner wall of the start of the outward expansion of the fracture caused by the fracture; finite element results with the experimental phenomena trend in line with the trend of the better.
2, finite element analysis shows that in the higher burst pressure, due to the shock wave in the specimen inside and outside the wall of the formation of a secondary plastic zone reflected back and forth between the specimen, so that the specimen wall thickness in the region of the equivalent plastic strain is larger than the inner and outer surfaces, the fracture occurs in the loading stage of the shock wave, damage to cracks start from the middle of the specimen wall thickness and to the inside and outside the wall to cause the fracture expansion: and in the lower burst pressure, the damage occurs in the free expansion stage, at this time, the specimen The whole into the tensile stress state, the greater the equivalent plastic product at the inner wall, fracture from the inner surface to the outer wall of the start of shear expansion.
3, the relevant experiments in some of the outer wall of the Razhong fracture phenomenon, may be related to the specimen geometry, material defects and other factors, for the defects of titanium coils on the impact of burst damage characteristics deserve further attention.
