Finite element (FE) modeling of instrumented dynamic indentation experiments in a miniature Kolsky bar is undertaken. Geometry, including an output bar with machined spherical indenter tip, and velocity history boundary conditions are extracted directly from experimental diagnostics. The test material (i.e., substrate) is polycrystalline aluminum alloy Al 6061-T6. The constitutive model used in simulations accounts for isotropic elasticity and isotropic plasticity with strain hardening, strain-rate hardening, and thermal softening under adiabatic conditions. The FE model, with representative material parameters culled from the literature, accurately reproduces the curvature of the experimental load versus depth data for three different experimental indentation velocity histories. A framework for dimensional analysis of instrumented dynamic spherical indentation is set forth, improving upon prior work. Parametric FE simulations reveal sensitivity, or lack thereof, of the predicted response to variations in the proposed independent dimensionless variables encompassing material properties. For the indenter size, maximum depth, and maximum strain rate imposed experimentally on the order of 10${}^3$/s, force-depth predictions are nearly unaffected by realistic variations in mass density, melting temperature, and thermal softening parameters when the sample is initially at room temperature. Predictions are affected by elastic constants (the elastic modulus and to a lesser extent, Poisson’s ratio), initial yield strength, two strain hardening parameters, and strain rate sensitivity. Predictions are also notably affected by initial temperature, with thermal softening prominent at high enough initial temperature or much higher loading rates. Based on the dimensional analysis, static indentation and elevated temperature indentation experiments are proposed for extraction of quasi-static and thermal material properties from previously uncharacterized metals, and dynamic indentation is proposed for extraction of rate sensitivity that cannot be obtained from static tests. Rate sensitivity obtained in this way from the novel instrumented dynamic spherical indentation experiments and FE simulations produces a parameterized stress–strain response for Al 6061-T6 reasonably validated by external studies for strain rates up to the order of 10${}^3$/s.

对微型 Kolsky 棒中的仪器化动态压痕实验进行了有限元 (FE) 建模。几何形状（包括带有机加工球形压头尖端的输出杆）和速度历史边界条件直接从实验诊断中提取。测试材料（即基板）为多晶铝合金Al 6061-T6。模拟中使用的本构模型考虑了绝热条件下具有应变硬化、应变率硬化和热软化的各向同性弹性和各向同性塑性。FE 模型具有从文献中提取的代表性材料参数，可准确再现三种不同实验压痕速度历史的实验载荷曲率与深度数据的关系。提出了仪器化动态球形压痕的尺寸分析框架，改进了先前的工作。参数 FE 模拟揭示了对所提出的包含材料特性的独立无量纲变量的变化的预测响应的敏感性或缺乏敏感性。对于实验上施加的压头尺寸、最大深度和最大应变率约为 10${}^{\mathrm{3个}}$/s，当样品最初处于室温时，力深度预测几乎不受质量密度、熔化温度和热软化参数的实际变化的影响。预测受弹性常数（弹性模量和较小程度的泊松比）、初始屈服强度、两个应变硬化参数和应变率敏感性的影响。预测也显着受初始温度的影响，在足够高的初始温度或更高的加载速率下热软化显着。基于尺寸分析，提出了静态压痕和高温压痕实验，用于从以前未表征的金属中提取准静态和热材料特性，并提出了动态压痕，用于提取无法从静态测试中获得的速率灵敏度。以这种方式从新型仪器化动态球形压痕实验和 FE 模拟中获得的速率灵敏度为 Al 6061-T6 产生了参数化的应力-应变响应，并通过外部研究对高达 10 的应变率进行了合理验证${}^{\mathrm{3个}}$/秒。