Experimental and Analytical Investigation into the Non-Linear Behavior of 2" and 4", 90 degree, Large Radius, Schedule 10, Stainless Steel Elbows Under Monotonic, Cyclic and Rate Dependent Loading

elbows;finite element analysis;piping

Wilkins, James Kevin ; Vernon C. Matzen, Committee Chair,Wilkins, James Kevin ; Vernon C. Matzen ; Committee Chair

University:North Carolina State University

关键词: elbows;    finite element analysis;    piping;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/834/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

This study investigates the behavior of stainless steel, butt welded elbows under a variety of loading conditions.The out-of-plane performance of 2 inch, schedule 10 elbows was examined and compared with analyses obtained from ANSYS using element SHELL181.The correlations between measured and simulated curves for load vs. displacement and strains were excellent.Also, the in-plane experimental behavior of 4 inch, schedule 10 elbows was examined and compared with SHELL181 analysis results for both opening and closing modes.In general, the correlation was quite good for both the global behavior and the local strain measures.The cyclic behavior of 2 inch, schedule 10 elbows was also measured.A one and three-fourths cycle test on a 2 inch, schedule 10 elbow was performed and compared with SHELL181 using both kinematic and isotropic hardening rules.The first quarter cycle performance of both analyses was quite good, but as deformation continued the isotropic results deviated significantly while the kinematic results remained quite good. Finally, the effect of loading rate on 4 inch, schedule 10 elbows was examined for the in-plane closing. The specimens were loaded at 0.5 mm/sec, 5 mm/sec and 50 mm/sec.With an increase in closure rate, an increased deviation from the analytical results was observed.By taking strain rate hardening effect into account the correlation improved greatly.The initial conclusion from these tests is that SHELL181 can provide excellent correlation under quasi-static loading, but at faster rates the effect of strain rate hardening may need to be implemented in the FEA.