Abstract In this paper, the ratcheting phenomena in the tubesheet of a heat exchanger, which made of modified 9Cr–1Mo steel, has been investigated. The nonlinear isotropic/kinematic hardening model (combined model) is used to investigate the progressive strains due to the cyclic pressure and temperature loading. Therefore, three series of tests were carried out at different temperatures (room temperature, 300 C ∘ , 520 C ∘ ) to gain stable hysteresis cycles and to obtain the hardening parameters of the desired material. Via least-squares nonlinear regression, the constitutive coefficients are obtained. In addition the effect of tube number on the progressive strains has been investigated. Therefore, three models of tubesheets with different tube numbers are considered. The results show that the progressive strains initially are significant at each cycle and gradually decrease from their initial amount, they reach a stable state, as the number of the tubes increases, and the more progressive strain accumulates.

中文翻译：

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使用非线性各向同性/运动硬化模型对换热器管板进行棘轮评估

摘要 本文研究了由改性 9Cr-1Mo 钢制成的换热器管板中的棘轮现象。非线性各向同性/运动硬化模型（组合模型）用于研究由于循环压力和温度载荷引起的渐进应变。因此，在不同温度（室温、300℃∘、520℃∘）下进行了三个系列的测试，以获得稳定的滞后循环并获得所需材料的硬化参数。通过最小二乘非线性回归，获得本构系数。此外，还研究了管数对渐进应变的影响。因此，考虑了三种不同管数的管板模型。