针对均匀、各向同性、幂律硬化的金属材料圆片试样,以圆柱平面小冲杆对试样圆面中心法向施加压载荷,提出基于能量密度等效的、用于描述试样几何尺寸、材料本构关系参数、载荷和位移之间关系的圆柱平面-小冲杆试验(Flat small punch test,F-SPT)弹塑性模型,并提出获取材料应力-应变曲线和力学性能指标的F-SPT新方法.通过有限元分析对不同弹性模量、屈服强度和硬化指数组合的48种预设材料进行新方法的数值验证,以及对10种金属材料完成F-SPT,结果表明,由新方法获得的应力-应变曲线与有限元分析预设曲线和传统单轴拉伸试验结果吻合良好,此外,由新试验方法获得的弹性模量、屈服强度和抗拉强度与单轴拉伸试验结果误差大部分低于7％.
Novel Flat-SPT Method for Obtaining Mechanical Properties of Ductile Materials and Its Application
For homogeneous,isotropic and power-law hardening discs under normally loading at its center by a small punch with a flat indenter,based on the energy density equivalence,a novel elastic-plastic model to describe the relationship between the disc dimensions,power-law parameters,load and displacement is proposed,and a flat small punch test(F-SPT)method for obtaining the stress-strain curves and mechanical properties of the materials is developed.Numerical verifications are carried out using 48 kinds of materials with various combinations of elastic modulus,yield strength,and hardening exponent,and F-SPT are conducted for ten metallic materials.The results show that the stress-strain curves obtained by this method are consistent with those preset in finite element analysis and those obtained by uniaxial tensile tests.In addition,the elastic modulus,yield strength and tensile strength obtained by the novel method are in agreement with the uniaxial tensile test results.
small punch testenergy density equivalencepower-law materialsstress-strain relationshipmechanical properties
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