Papers by Author: Cheng Cai Liu

Abstract: The root shrinkage cavity (SCRT) is one special kind of high-energy welding defect which can remarkably decreases mechanical strength and induces fatigue crack, so it is of great significance to numerically study its formation mechanism. In this paper, a set of Niyama criterion program based on temperature field was developed and adopted to numerically predict it in non-penetration 2219 aluminum alloy electron beam weld. The results indicate that the formation possibility of SCRT defect decreases with the increased welding speed. In addition, the error of simulated SCRT in the weld penetration direction is 8.76%, while the error in the weld width direction is 23.46%, which shows good agreement with experimental comparison samples. All the simulation and experimental results validate the correctness and feasibility of the developed Niyama criterion program.