摘要
为描述材料在塑性成形中的复杂硬化行为,提出了一种基于三次贝塞尔曲线的屈服轨迹离散插值型描述方法,以及后继屈服轨迹演化模型。针对Khan A S等采用Al6061-T6511铝合金进行拉伸-扭转复合预加载后,采用10-5量级的屈服应变阈值时,二维应力空间屈服轨迹表现出极其强烈的大小、中心点和形状变化的实验结果,构造了相应的离散插值型屈服轨迹数值模型,通过拟合实验结果得到了各预应变条件下的曲线参数;提出了描述后继屈服轨迹大小、中心点和形状变化的拟合模型以描述材料的各向同性强化、随动强化和畸变强化行为。与采用应力不变量的建模方法相比,这种屈服模型是依据屈服轨迹的几何形状建立的,具有较大的灵活性。
To describe the complex hardening behavior of materials in plastic forming,a discrete interpolation method for yield locus based on third-order Bezier curve and a subsequent yield locus evolution model were proposed.Based on the results of the experiment carried out by Khan A S et al.that in the tensile-torsional composite preloading which was applied on Al6061-T6511 aluminum alloy with yield strain threshold of 10-5,extremely strong size,center point and shape change of the yield locus in two-dimensional stress space were observed,the corresponding discrete interpolation yield locus model was constructed,with the curve parameters determined by fitting the experimental result under each pre-strain condition.The fitting models describing size,center point and shape change of the subsequent yield were proposed to describe the isotropic,kinematic and distortional hardening behaviors.Compared with those yield models using stress invariant,this model is based on the geometric feature of the yield locus which is more flexible.
作者
林良毅
董湘怀
LIN Liang-yi;DONG Xiang-huai(Institute of Plastic Forming Technology and Equipment,Shanghai Jiao Tong University,Shanghai 200030,China;National Engineering Research Center of Die and Mould CAD,Shanghai Jiao Tong University,Shanghai 200030,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期288-294,共7页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51775335
51635005)
关键词
贝塞尔曲线
屈服准则
畸变硬化
后继屈服轨迹
演化模型
Bezier curve
yield criterion
distortion hardening
subsequent yield locus
evolution model
