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Nonlinear Variation of Chord Modulus of Mild Steel During Cyclic Loading-Unloading at Different Temperatures

Liwen Guan¹, Xiaoteng Wang^2,*, Tang Biao²

1 Department of mechanical engineering, Tsinghua University, Beijing, 100084, China
2 Research Institute of Smart Manufacturing, China Railway Construction Heavy Industry Corporation Limited, Changsha, 410100, China

* Corresponding Author: Xiaoteng Wang. Email:

The International Conference on Computational & Experimental Engineering and Sciences 2025, 33(2), 1-4. https://doi.org/10.32604/icces.2025.012534

Abstract

By using the continuous cyclic loading-unloading tensile test method, the nonlinear variation behavior of the chord modulus of mild steel under different temperature conditions was systematically investigated, and the corresponding relationship between plastic strain and chord modulus during the cyclic loading-unloading process was clarified. Through the analysis of test data, the variation trends and quantitative corresponding models of plastic strain and chord modulus at different temperatures were established. The research results show that under constant temperature conditions, as the plastic strain increases to 10%, the chord modulus attenuation process presents a significant two-stage characteristic - in the initial stage (ε_p≤0.02), it shows a rapid decline; in the subsequent stage (ε_p>0.02), the attenuation rate significantly decreases and tends to stabilize. The temperature effect analysis shows that although the variation trends under different temperature conditions remain consistent, the decline rate of the material's chord modulus decreases as the tensile temperature increases. Further analysis reveals that when mild steel is in the temperature range of 20 - 300℃, the influence of plastic strain on its chord modulus has engineering significance, and the nonlinear mechanical behavior's impact on structural deformation should be fully considered in the design of precision welding processes.

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Keywords

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