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.

中文翻译：

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通过基于3D成像的微机械模拟检查球墨铸铁中的局部应变场演变

比较了两个球墨铸铁样品的显微数字体积相关性（DVC）和有限元预凝析应变评估。通过DVC获得\ textit {situ} 3D同步加速器层成像图像中的位移场。随后，将结节视为空隙，从图像中明确地划分出微结构。从DVC测量中应用边界条件。考虑到图像分割相关的不确定性，并且在应变水平之间的差异方面可以忽略不计。比较了在大石墨结节成核的空隙之间的聚结韧带中的宏观以及局部应变水平。宏观应变水平是一致预测的。对于其中一个标本，观察到非常好的一致性，而第二个样品的应变水平存在一些差异。鉴于这些差异，讨论了建模和数值框架的局限性。开始讨论使用应变作为聚结指示器。