采用应变梯度硬化模型预测黄铜薄板微弯曲弯矩  

Microbending Moment of Brass Foils Based on Strain Gradient Hardening Model

作　　者：李河宗[1,2] 董湘怀[1] 申昱[1] Alexander Diehl Hinnerk Hagenah Ulf Engel Marion Merklein 

机构地区：[1]上海交通大学塑性成形工程系,上海200030 [2]河北工程大学机械电子工程学院,河北邯郸056038 [3]纽伦堡大学制造技术研究所,德国埃尔兰根91058

出　　处：《上海交通大学学报》2011年第11期1668-1672,1683,共6页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(50835002;50975174;50821003)~~

摘　　要：通过黄铜板料微弯曲实验,发现其弯曲弯矩存在明显的尺寸效应现象,随板料厚度的减小,弯曲弯矩增大.采用经典塑性理论和不同的应变梯度理论对微弯曲弯矩进行了预测,对比分析结果表明:修正的Nix-Gao模型的预测结果更接近于实验结果,并且得出了合理的内禀尺寸表达式;该内禀尺寸与材料的剪切模量、初始屈服极限、柏氏矢量和板料厚度方向上的孪晶数有关.The microbending experiments of brass were investigated and there exist the obvious size effects that bending moment increases with foil thickness decreasing.The microbending moments are predicted by classical plastic theory and different strain gradient theories,which shows that the predicted results based on the modified Nix-Gao model are very close to the experimental data and the equation of material intrinsic length is reasonable.The material intrinsic length is the function of shear modulus,initial yield strength,Burger＇s vector and twins layers across the foil thickness.

关 键 词：CuZn37黄铜 微弯曲 弯矩 应变梯度 内禀尺寸 

分 类 号：TG301[金属学及工艺—金属压力加工]