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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。
Based on the ABAQUS platform, a full-process finite element model of TA18 high-strength titanium tube was established to study the stress-strain history of the material in the medial, lateral and neutral layers. The results show that the material in the bending neutral layer will undergo more complicated tangential stress and strain history than the material in the middle and the outside during the bending process. The material of the neutral layer in the initial bending end has less stress and undergoes the tensile stress Change the history, while the rest of the region experienced a stress-pull history of stress and the tensile stress is much greater than the compressive stress; the stress history of the outer wall material of the neutral layer is similar to the inner wall material at the same position, but the stress value is significantly greater than the inner wall ; The material located at the front end of the curved neutral layer is always subjected to tensile strain; the material at the middle and the rear end undergoes a strain history from compression to tension and the tensile strain value of the middle material is much larger than the tensile strain at the back end. During unloading rebound, the tangential stress of the material located at the front end of the curved inner wall increases. The material tangential stresses of the inner and outer walls at the outer side of the curve have experienced the history of unloading and reverse loading. The tangential stress of the outer and inner wall materials only experienced different degrees of unloading.