Microscopic digital volume correlation (DVC) and finite element precoalescence strain evaluations are compared for two nodular cast iron specimens. Displacement fields from \textit{in-situ} 3D synchrotron laminography images are obtained by DVC. Subsequently the microstructure is explicitely meshed from the images considering nodules as voids. Boundary conditions are applied from the DVC measurement. Image segmentation-related uncertainties are taken into account and observed to be negligible with respect to the differences between strain levels. Macroscopic as well as local strain levels in coalescing ligaments between voids nucleated at large graphite nodules are compared. Macroscopic strain levels are consistently predicted. A very good agreement is observed for one of the specimens, while the strain levels for the second specimen presents some discrepancies. Limitations of the modeling and numerical framework are discussed in light of these differences. A discussion of the use of strain as coalescence indicator is initiated.
翻译:微缩结构从将结核视为空隙的图像中明显抽取; 从DVC测量中适用边界条件; 将与图像分离有关的不确定性考虑在内,并观察到与菌株水平差异有关的不确定性可忽略不计; 对大石墨结核中核化的空隙之间粘合的硬化物中,对大型岩浆悬浮物的巨型和局部强度进行比较; 不断预测大型石墨结核中,显形线的强度水平; 观察到一个样本的高度一致,而第二个样本的强度则显示出一些差异; 根据这些差异,讨论了模型和数字框架的局限性; 开始讨论在煤化指标中使用菌株的问题。