A Study on Non-proportional Biaxial Behavior of Cyclic Ratcheting

• Main Authors: Ching-Heng Chou, 周慶珩
• Other Authors: Dar-Yun Chiang
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/75894350688730958234

碩士 === 國立成功大學 === 航空太空工程學系 === 88 === By introducing the A-F non-linear kinematic hardening rule into element behavior, the modified Distributed Element Model (DEM) is capable of adequately describing the behavior of cyclic relaxation and ratcheting of materials. However, it still has the disadvantage of not being able to describe appropriately the long-term behavior of cyclic ratcheting. The objective of this study is to improve the modeling capability of the modified DEM for ratcheting rate problem of long-term loading path. To account for more complex behavior, we modify the A-F non-linear kinematic hardening rule for long-term behavior of cyclic ratcheting according to experimental observations. In this study, we simulate the behavior of non-proportional ellipse-shaped、apple-shaped compression-torsion cyclic ratcheting and two-step uniaxial cyclic ratcheting of 1070 steel. It is concluded that the effect of the modified hardening rule plays an important role in demonstrating physical mechanisms and characterizing complex behavior of real materials.