The subroutine UEL embedded in commercial FEM software ABAQUS is utilized to develop a user element based on the material of pressure-dependent elasto-plastic Cosserat continuum model. The user element adopt plane eight-node isoparametric unit which include three degree of freedom (two translation and one rotation) at each node. The Drucker-Prager material model with associate flow rule is used, and the stress integration algorithm is four-order Runge-Kutta method. The user element is used to analyze the influence of mesh density and the material characteristic length in the material localization problem. The results show that the thickness of shear band and the equivalent plastic strain are independent of mesh density, with the increase of the material characteristic length, the thickness of shear band and the equivalent plastic strain decrease constantly.%利用大型有限元软件ABAQUS提供的接口程序UEL,开发了压力相关弹塑性Cosserat连续体材料的用户单元.采用平面八节点等参单元,包括平动与转动三个自由度,考虑相关联流动的Drycjer-Prager材料模型,应力计算采用四阶龙格-库塔法.利用该单元分析了材料局部化问题中网格密度与材料特征长度的影响.结果表明,网格密度对材料剪切带厚度与等效塑性应影响很小；随着特征长度增大,剪切带厚度增大,等效塑性应变峰值减小.
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