CAJ | 학술논문

基于ABAQUS平台建立TA18高强钛管数控弯曲成形全过程有限元模型，研究弯曲内、外侧和中性层位置材料经历的应力应变历史过程。结果表明，弯曲过程中，位于弯曲中性层的材料会经历较内侧和外侧材料复杂的切向应力、应变历史；位于弯曲初始端的中性层内壁材料应力较小，且经历由拉到压的变化历史，而其余区域材料经历由压到拉的应力历史，且拉应力较压应力大得多；中性层外壁材料的应力历史与其同位置的内壁材料的相似，但其应力值明显大于内壁的值；位于弯曲中性层前端的材料始终经受拉应变；位于中部和后端的材料则经历由压到拉的应变历史，且中部材料的拉应变值较后端的拉应变值大很多。在卸载回弹过程中，位于弯曲内侧外壁前端的材料切向应力增大；位于弯曲外侧、内侧的内、外壁的材料切向应力都经历了卸载和反向加载的历史；几何中性层的外壁和内壁材料切向应力只经历了不同程度的卸载。
기우ABAQUS평태건립TA18고강태관수공만곡성형전과정유한원모형，연구만곡내、외측화중성층위치재료경력적응력응변역사과정。결과표명，만곡과정중，위우만곡중성층적재료회경력교내측화외측재료복잡적절향응력、응변역사；위우만곡초시단적중성층내벽재료응력교소，차경력유랍도압적변화역사，이기여구역재료경력유압도랍적응력역사，차랍응력교압응력대득다；중성층외벽재료적응력역사여기동위치적내벽재료적상사，단기응력치명현대우내벽적치；위우만곡중성층전단적재료시종경수랍응변；위우중부화후단적재료칙경력유압도랍적응변역사，차중부재료적랍응변치교후단적랍응변치대흔다。재사재회탄과정중，위우만곡내측외벽전단적재료절향응력증대；위우만곡외측、내측적내、외벽적재료절향응력도경력료사재화반향가재적역사；궤하중성층적외벽화내벽재료절향응력지경력료불동정도적사재。
A finite element model for the whole NC bending process of TA18 high-strength titanium alloy tubes is established based on ABAQUS platform . The variation characteristics of axial stress and axial strain in the outer and inner zones of the ben-ding and the neutral layer zone are studied . The results show that :During the bending process , the material in the neutral layer zone undergoes more complicated axial stress-strain history . The material locating on the intersection between the initial bending section and the inside wall of the neutral layer zone , undergoes a history of the axial stress varying from a small tension to a small compression . However , the material in other sections still on the inside wall of the neutral layer zone undergoes a history of the axial stress varying from a small compression to a large tension . The material on the outside wall of the neutral layer zone , un-dergoes the same axial stress history but with larger stress values . The material in the initial bending section of the neutral layer zone undergoes the same axial tensile strain history . The material in the midst section and the back section of the neutral layer zone undergoes a variation of the axial strain from a compression to a tension , however the values in the midst section are larger than the back .During unloading process ,the material in the inside and outside walls of the inner and outer zones of the bending undergoes an unloading-reloading history ,and the material in the initial bending section of outside wall of the outer zone just in-creases . However , the material in the inside and outside wall of the neutral layer zone only undergoes a simple unloading history .