A calibration function for notched cylindrical tension specimens, based on the common format equation : Numerical and experimental data analysis
A calibration function for notched cylindrical tension specimens, based on the common format equation : Numerical and experimental data analysis
复制标题
基于通用格式方程的缺口圆柱形拉伸样本的校准函数：数值和实验数据分析
DOI：
10.1016/0013-7944(95)00224-3
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发表时间：
1996
影响因子：
5.4
通讯作者：
H. Argomedo
中科院分区：
文献类型：
--
作者：
J. Donoso;F. Labbé;H. Argomedo
二维断裂试样的校准函数，代表载荷，塑性位移和未开裂韧带长度之间的关系，最近已经开发通过使用的通用格式方程（CFE）提出的Donoso和Landes。在CFE中，断裂试样的行为表示为三项的乘积：约束因子φ f;几何和韧带尺寸相关函数G;以及硬化函数H。CFE方法的主要假设之一是，对于任何给定的二维断裂试样几何形状，可以通过使用适当的G函数从材料应力-应变行为预测性能。换句话说，材料的拉伸性能，通常获得与光滑的圆柱形试样，被转移到缺口二维断裂试样的硬化功能H的装置。在Donoso和Landes的另一项工作中，进一步表明，平面二维断裂试样的校准曲线也可以直接从圆柱形试样拉伸数据中获得，使用基于CFE的模型。在该模型中，归一化载荷与真实应力直接相关，归一化位移与真实应变直接相关，如从用圆柱形试样进行的常规拉伸试验中获得的。在这种情况下，人们可以预期，相同的方法可以应用到转移的材料性能从光滑的圆柱形试样的缺口圆柱形试样。后者是一种几何形状，目前值得大量关注，因为与平面试样相比具有一些优势。在这项工作中，铁素体钢和焊缝金属的数值和实验数据，获得和分析，以开发校准功能缺口圆柱形试样在拉伸载荷下，基于CFE方法。它示出，获得的几何函数，这取决于切口扇区（韧带的试样）的直径d的比率，试样的圆柱形部分的直径D，规范化的载荷塑性位移数据的一个共同的格式，仅取决于材料的性能。
Calibration functions for two-dimensional fracture test specimens, representing the relation between load, plastic displacement and uncracked ligament length, have been recently developed through the use of the Common Format Equation (CFE) proposed by Donoso and Landes. In the CFE, the behavior of the fracture test specimen is expressed as the product of three terms: a constraint factor, φ∗; a geometry and ligament size-dependent function, G, and a hardening function H. One of the main assumptions of the CFE approach is that, for any given two-dimensional fracture test specimen geometry, the behavior may be predicted from the material stress-strain behavior, by using the appropriate G function. In other words, the material tensile properties, normally obtained with smooth cylindrical specimens, are transferred to the notched two-dimensional fracture specimens by means of the hardening function H. In another work by Donoso and Landes it has been further shown that calibration curves for planar, two-dimensional fracture specimens, may also be obtained directly from cylindrical specimen tensile data, using a model based on the CFE. In this model, the normalized load is directly related to true stress, and the normalized displacement to true strain, as obtained from a conventional tensile test performed with cylindrical specimens. In this context, one can expect that the same approach may be applied to the transfer of material properties from smooth cylindrical specimens to notched cylindrical specimens. The latter is a type of geometry that is deserving a lot of attention presently, because of some advantages when compared to planar specimens. In this work, both numerical and experimental data for a ferritic steel and a weld metal, are obtained and analysed in order to develop the calibration function for notched cylindrical specimens under tension load, based on the CFE approach. It is shown that the geometry function obtained, which depends on the ratio of the diameter d of the notched sector (the ligament of the specimen), to the diameter D of the cylindrical portion of the specimen, normalizes the load-plastic displacement data to a common format that depends solely on the material properties.