Fracture Toughness by Small Punch Testing
Fracture Toughness by Small Punch Testing
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DOI：
10.1520/jte10392j
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发表时间：
1995
影响因子：
1.2
通讯作者：
Derek R. Petersen;J. Foulds;P. Woytowitz;TK Parnell;C. Jewett
中科院分区：
文献类型：
--
作者：
Derek R. Petersen;J. Foulds;P. Woytowitz;TK Parnell;C. Jewett
目前，小冲孔测试被用于经验估计化石电厂服务中一系列部件的材料断裂外观转变温度（FATT），该测试已进一步发展为直接估计KIc和JIc，其方式是分析性的，与材料无关，并且不需要事先了解材料的机械性能。该过程遵循基于连续介质材料韧性概念的方法，其中断裂标准是通过材料的连续应力-应变变形特性来定义和测量的。该程序具体涉及使用大应变有限元（FE）分析计算在小冲压试验试样中裂纹起裂位置和时间累积的“局部”应变能密度。由于该程序还包括从小冲头负载-位移曲线估计材料的单轴拉伸应力-应变行为，因此断裂韧性和单轴拉伸行为都是通过一次测试确定的。该程序的开发是为了利用微型样品去除技术，可以“无损地”应用于操作部件。给出了一系列钢的测试结果。
The small punch test, currently being used to empirically estimate the material fracture appearance transition temperature (FATT) of a range of components in fossil power plant service, has been further developed for direct estimation of KIc and JIc in a manner that is analytical, material-independent, and requires no prior knowledge of material mechanical properties. The procedure follows an approach that is based on the continuum material toughness concept wherein the criterion for fracture is defined and measured via the continuum stress-strain deformation properties of the material. The procedure specifically involves computing the “local” strain energy density accumulated at the location and time of crack initiation in the small punch test specimen using large-strain finite element (FE) analysis. Since the procedure also includes estimation of the material uniaxial tensile stress-strain behavior from the small punch load-displacement curve, both the fracture toughness and the uniaxial tensile behavior are determined from a single test. The procedure has been developed in order to take advantage of the miniature sample removal techniques that can be applied “nondestructively” to operating components. Results are presented on a range of steels.