An Axial-Torsional, Thermomechanical Fatigue Testing Technique
An Axial-Torsional, Thermomechanical Fatigue Testing Technique
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DOI：
10.1520/stp16218s
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发表时间：
1995-05
期刊：
影响因子：
--
通讯作者：
S. Kalluri;P. Bonacuse
中科院分区：
文献类型：
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作者：
S. Kalluri;P. Bonacuse
摘要：提出了一种对薄壁管试样进行应变控制、热机械、轴扭疲劳试验的技术。在这些试验中需要三种加载波形，即轴向应变波形、工程剪切应变波形和温度波形。机械应变波形与温度和轴向应变波形之间的相位关系用于定义一组四个轴向扭转热机械疲劳（AT-100）试验。实时测试控制（3个通道）和数据采集（最少7个通道）使用C语言编写的软件程序进行，并在个人计算机上执行。采用AT-188试验技术研究了钴基高温合金Haynes 188的轴扭热机械疲劳行为。选择用于AT-100试验的最高和最低温度分别为760和316摄氏度。详细的测试系统，薄壁管试样的动态温度分布的校准，热应变补偿技术，和测试控制和数据采集方案，报告。在先前的研究中，对Haynes 188在316和760 ℃下的等温、轴向、扭转以及同相和异相轴向扭转疲劳行为进行了表征。将AT-TMF测试中Haynes 188的循环变形和疲劳行为与之前报道的该高温合金在最高和最低温度下的等温轴向扭转行为进行比较。
Abstract : A technique for conducting strain-controlled, thermomechanical, axial-torsional fatigue tests on thin-walled tubular specimens was developed. Three waveforms of loading, namely, the axial strain waveform, the engineering shear strain waveform, and the temperature waveform were required in these tests. The phasing relationships between the mechanical strain waveforms and the temperature and axial strain waveforms were used to define a set of four axial-torsional, thermomechanical fatigue (AT-TMF) tests. Real-time test control (3 channels) and data acquisition (a minimum of 7 channels) were performed with a software program written in C language and executed on a personal computer. The AT-TMF testing technique was used to investigate the axial-torsional thermomechanical fatigue behavior of a cobalt-base superalloy, Haynes 188. The maximum and minimum temperatures selected for the AT-TMF tests were 760 and 3l6 dec C, respectively. Details of the testing system, calibration of the dynamic temperature profile of the thin-walled tubular specimen, thermal strain compensation technique, and test control and data acquisition schemes, are reported. The isothermal, axial, torsional, and in- and out-of-phase axial-torsional fatigue behaviors of Haynes 188 at 316 and 760 deg C were characterized in previous investigations. The cyclic deformation and fatigue behaviors of Haynes 188 in AT-TMF tests are compared to the previously reported isothermal axial-torsional behavior of this superalloy at the maximum and minimum temperatures.