Ferromagnetic shape memory alloys (MSMAs), such as Ni-Mn-Ga single crystals, can exhibit the shape memory effect due to an applied magnetic field at room temperature. Under a variable magnetic field and a constant bias stress loading, MSMAs have been used for actuation applications. This work introduced a new feature to the existing macroscale magneto-mechanical model for Ni-Mn-Ga single crystal. This model includes the fact that the magnetic easy axis in the two variants is not exactly perpendicular as observed by D silva et al. This offset helps explain some of the power harvesting capabilities of MSMAs. Model predictions are compared to experimental data collected on a Ni-Mn-Ga single crystal. The experiments include both stress-controlled loading with constant bias magnetic field load (which mimics power harvesting or sensing) and fieldcontrolled loading with constant bias compressive stress (which mimics actuation). Each type of test was performed at several different load levels, and the applied field was measured without the MSMA specimen present so that demagnetization does not affect the experimentally measured field as suggested by Eberle et al. Results show decent agreement between model predictions and experimental data. Although the model predicts experimental results decently, it does not capture all the features of the experimental data. In order to capture all the experimental features, finally, a generalized regression neural network (GRNN) was used to train the experimental data (stress, strain, magnetic field, and emf) so that it can make a reasonably better prediction.
翻译:熔磁形状内存合金( MSMAs), 如 Ni- Mn- Ga 单晶体等, 可以在室内温度下显示应用磁场的形状内存效果。 在可变磁场和常态偏差压力加载下, MMSMAs 已被用于振动应用。 这项工作为 Ni- Mn- Ga 单晶体的现有大型磁磁机机模型引入了新的特性。 这个模型包括两个变体中的磁易轴没有像 Dsilva 等人所观察到的那样完全穿透。 这可以解释MSMAs 的一些电源采集能力。 模型预测与在 Ni- Mn- Ga 单晶体上收集的实验数据进行比较。 实验中包括以恒定偏偏磁场负荷( 模拟电磁力采集或感测) 和以恒定的偏偏偏缩后加载( 模拟振动) 。 每种测试都是在几个不同的负荷级别上进行, 并且应用的字段在没有MSMA 标上进行测量, 因此, IMMA 的内存的某些能力收集能力将不合理地进行精确化。 实验性实验性实验性数据最终显示所有实验性测测结果。 。 。 以正正正等的实验性 。 实验性 。 实验性 实验性 数据 显示所有实验性 。