...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Materials at High Temperatures >Influence of bending on low cycle fatigue life of cylindrical test pieces at elevated temperature
【24h】

Influence of bending on low cycle fatigue life of cylindrical test pieces at elevated temperature

机译：弯曲对高温下圆柱试样低周疲劳寿命的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In fatigue testing, normally cyclic-through-zero-testing, reversed-bending misalignment caused by load-strain offset from the frame centre line in a non-rigid system can have the most critical influence on low cycle fatigue (LCF) endurances. Hence, a unique systematic experimental study was established to investigate the influence of reversed bending on fatigue properties at high temperature.A special test programme provides a total of 18 tension-compression fatigue tests on alloy Nimonic 101 at 850°C. Prior to start of the fatigue test, bending was adjusted, whereby three different bending levels were of interest: a first level at bending rate of less than 2% addressed to good alignment, asecond level at a medium bending rate of 20% and finally, a third level at a high bending rate of 40%.Bending measurements follow a code of practice. Standard strain controlled fatigue tests wereconducted at two typical load levels. A low level of total strain range represents the elastic regime anda high level represents the elasto-plastic regime, which is expected to be the most important level. The advanced features of this experimental work deals with the development of a specialcomposite test piece and the application of a commercial alignment fixture to adjust bending dueto lateral grip offset. The test results show that in the elasto-plastic regime, a systematic reduction ofLCF endurance of up to factor two with increasing superimposed bending rate of up to 40%. In the elastic regime, no systematic effect was observed. The within-laboratory repeatability was found to besmall, demonstrating good testing practice with regard to strain control and temperature control as well.
机译：在疲劳测试中，在非刚性系统中，正常情况下通过零循环进行循环测试，即由于载荷-应变偏离框架中心线而引起的反向弯曲未对准可能会对低循环疲劳（LCF）耐久性产生最关键的影响。因此，建立了一个独特的系统实验研究来研究反向弯曲对高温下疲劳性能的影响。一个特殊的测试程序在850°C下对Nimonic 101合金进行了总共18次拉伸压缩疲劳测试。在疲劳测试开始之前，需要调整弯曲度，从而关注三个不同的弯曲度：弯曲度小于2％的第一个弯曲度表示良好的对准，中等弯曲度的第二个弯曲度表示20％，最后，弯曲率达到40％时达到第三级。弯曲测量遵循操作规范。在两个典型的载荷水平下进行了标准的应变控制疲劳试验。总应变范围的低水平代表弹性状态，高水平代表弹塑性状态，预计这是最重要的水平。该实验工作的高级功能涉及开发特殊的复合试件以及应用商用对准夹具来调整由于侧向抓地力偏移而引起的弯曲。测试结果表明，在弹塑性状态下，系统的LCF耐力系统降低了多达2倍，叠加弯曲率提高了40％。在弹性状态下，未观察到系统性作用。发现实验室内的重复性很小，在应变控制和温度控制方面也表现出良好的测试实践。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号