Abstract The accuracy of rock property measurements in real-time heating loading tests has been considered as questionable due to the thermal effect on loading platens. In this study, the impact of steel platen performance at high temperatures (up to 1000 °C) on granite property measurements is analysed by numerical simulations. Simulation results show that a smaller stiffness of the loading platen can result in specific stress redistributions, increasing micro cracks, and peak axial stress reduction of the sample during uniaxial compression. This can subsequently lead to an underestimation of failure stress and strain. However, the decreasing platen stiffness with rising temperature does not produce any remarkable impact on the temperature-dependent property measurements of the selected Eibenstock granite (EG) heated up to 1000 °C. This is related to the progressively decreased strength of EG and the consequently negligible deformation of the softened platen at elevated temperatures. Therefore, the loading platen can still be treated as ideal stiff. Considering the big variations in strengths and thermal response of different rock types, the suggested procedure to obtain reliable rock properties at high temperatures (e.g. above 800 °C) is to perform an evaluation by replicating the lab tests via numerical simulations.

中文翻译：

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高温岩石力学试验中压板刚度的热效应

摘要 由于加载平台上的热效应，实时加热加载测试中岩石特性测量的准确性被认为是有问题的。在这项研究中，通过数值模拟分析了高温（高达 1000 °C）下钢板性能对花岗岩性能测量的影响。仿真结果表明，加载板的较小刚度会导致样品在单轴压缩过程中出现特定的应力重新分布、微裂纹增加和峰值轴向应力降低。这随后会导致对失效应力和应变的低估。然而，随着温度升高，压板刚度降低不会对加热至 1000 °C 的所选 Eibenstock 花岗岩 (EG) 的温度相关特性测量产生任何显着影响。这与 EG 的强度逐渐降低以及软化的压板在升高的温度下的变形可以忽略不计有关。因此，加载压板仍然可以被视为理想的刚度。考虑到不同岩石类型的强度和热响应的巨大变化，在高温（例如高于 800 °C）下获得可靠岩石特性的建议程序是通过数值模拟复制实验室测试来进行评估。