精密成形工程
精密成形工程
정밀성형공정
METAL FORMING TECHNOLOGY
2011年
6期
1-5,65
,共6页
晶体塑性模型%准隐式积分算法%显式有限元%板料成形
晶體塑性模型%準隱式積分算法%顯式有限元%闆料成形
정체소성모형%준은식적분산법%현식유한원%판료성형
crystal plasticity%semi implicit integration seheme%explicit FEM%sheet metal forming
参考经典的切线系数法,采用向前梯度法对修正的超弹性晶体塑性模型进行本构方程积分,提出了一种新的准隐式积分算法。该算法采用基于中间构型的超弹性晶体塑性模型,无需更新晶粒取向相关的状态变量;采用修正的超弹性框架,无需进行由Green-Naghdi材料共旋引起的旋转变换。这种准隐式积分算法兼有超弹性模型和切线系数法的优点。通过对铝合金筒形件拉深的模拟表明,该晶体塑性模型能有效地预测不同初始织构产生的不同制耳现象,同时具有很高的计算效率。
參攷經典的切線繫數法,採用嚮前梯度法對脩正的超彈性晶體塑性模型進行本構方程積分,提齣瞭一種新的準隱式積分算法。該算法採用基于中間構型的超彈性晶體塑性模型,無需更新晶粒取嚮相關的狀態變量;採用脩正的超彈性框架,無需進行由Green-Naghdi材料共鏇引起的鏇轉變換。這種準隱式積分算法兼有超彈性模型和切線繫數法的優點。通過對鋁閤金筒形件拉深的模擬錶明,該晶體塑性模型能有效地預測不同初始織構產生的不同製耳現象,同時具有很高的計算效率。
삼고경전적절선계수법,채용향전제도법대수정적초탄성정체소성모형진행본구방정적분,제출료일충신적준은식적분산법。해산법채용기우중간구형적초탄성정체소성모형,무수경신정립취향상관적상태변량;채용수정적초탄성광가,무수진행유Green-Naghdi재료공선인기적선전변환。저충준은식적분산법겸유초탄성모형화절선계수법적우점。통과대려합금통형건랍심적모의표명,해정체소성모형능유효지예측불동초시직구산생적불동제이현상,동시구유흔고적계산효솔。
A semi-implicit integration scheme for rate dependent crystal plasticity is proposed in this paper. The algorithm is similar to the tangent modulus method. A modified hyperelastic frame is adopted to circumvent the troublesome incremental objectivity encountered by the hypoelastic crystal plasticity models, especially when Green-Naghdi material co-rotational coordi- nate system （MCCS） is used, e.g. in many commercial explicit FEM software. The algorithm combines the advantages of the tangent modulus method and the hyperelastic frame. This algorithm is implemented into ABAQUS/Explicit to simulate deep drawing of aluminum alloy sheets with initial different textures. The predication of the earing profiles shows good agreement with the experimental results, and it is also found that the proposed model is computationally efficient.
