Applied Mechanics and Materials Vol. 750

Abstract: Three-dimensional crack behavior simulation analysis and anti-fracture design have been a main subject in fracture theory and engineering application. Piping system is a key part of nuclear power engineering. Utilizing the three-dimensional finite element analysis software ANSYS and the specialized crack analysis programs Franc3D, three-dimensional crack behavior and leak before break (LBB) case were simulated and evaluated of a pipe with a crack in waste heat exhaust system of China Experimental Fast Reactor ( CEFR ). In fast reactor, the piping is working under a high temperature. Therefore, the code RCC-MR.A16 was adopted that is suitable for materials and structural safety design at high temperature. Material used in this article is modified 9Cr1Mo-T91/P91. The analysis model of pipe section was built in three-dimensional entity structure containing a cracks and the high temperature and creep effects were considered. The simulation results show that creep contributes more effect on crack growth than fatigue. The evaluation results on LBB of studied T91 steel pipe with a crack-like defect can satisfy the need of LBB design guidelines. The research results can be referenced in pipe material choose, safety assessment and structural integrity evaluation of a pipe containing defects at high temperature in a fast reactor design.

Abstract: A drawing and forming technology is studied in this paper for a typical cylindrical component made by high strength steel plates of B340/590 and B400/780 with differential thickness. A finite element analysis is carried out using the software Dynaform to investigate the drawing and forming process of the cylinder. Some processing parameters obtained from the simulation are compared with the data from experiments. The results show that the effective control of blank sizes, holder force and loading modes can improve the thinning ratio of the tailor-welded materials. The drawing limit coefficient m=0.53 is determined by the test. The whole results are well matched in numerical simulations and physical experiments.