CAJ | 학술논문

利用有限元方法对不同圆环压缩过程中的分流行为进行模拟研究,揭示铝合金圆环压缩过程中分流行为的产生机理,并利用罗德系数、J_2应力偏量不变量等特征量对成形机理进行分析.结果表明:外侧施压时,随着高径比增大,难变形区明显扩大,向内侧流动的金属量逐渐减少,分流面位置明显左移;内侧施压时,随着摩擦因子增大,塑性区内应变类型由均一压缩类变为3种共存,此时向内侧流动的金属量增大,其流动分界面相对右移.
이용유한원방법대불동원배압축과정중적분류행위진행모의연구,게시려합금원배압축과정중분류행위적산생궤리,병이용라덕계수、J_2응력편량불변량등특정량대성형궤리진행분석.결과표명:외측시압시,수착고경비증대,난변형구명현확대,향내측류동적금속량축점감소,분류면위치명현좌이;내측시압시,수착마찰인자증대,소성구내응변류형유균일압축류변위3충공존,차시향내측류동적금속량증대,기류동분계면상대우이.
The mechanism of aluminium alloy diffluence behaviour was studied during the ring compression. The FEM simulations of ring compression under different deformation conditions were carried out. The plastic forming mechanism was investigated based on the Lode parameter and J_2 invariant of stress deviator. The results show that when the pressure is added on the external side, the metal flowing towards the internal hole decreases with increasing ratio of height to diameter, and the hard deforming zones expand and the diffluence surface shifts towards the left. When the pressure is added on the internal side, the metal flowing towards the internal hole increases with increasing friction factor, the diffluence surface shifts towards the right and the strain in the plastic area changes from the single compression mode into three coexistent modes.