Deviatoric stress generated within subducting slabs by the olivine–spinel transformation has been modeled by assuming the phases to be simply connected rather than comprising a mixture in which one phase is embedded within another. Here, we use a simplified model to explain how transformation strain is incorporated into a continuum model, and we then use the simplified model to explain quantitatively the origin of the unreasonably large deviatoric stresses predicted by existing slab models. We review experiments on the transformation of single-crystal samples and argue that they are consistent with the occurrence, at the grain scale, of deviatoric stresses comparable with those predicted (erroneously) to exist at the slab scale by those slab models. Using a simple example, we show that although large deviatoric stresses can exist at the grain scale, their average over a sample containing many grains can be hydrostatic. This leads us to the problem of modeling the microscale structure. We outline the therm...

中文翻译：

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界面动力学、晶粒尺度变形和多态性

由橄榄石-尖晶石转变在俯冲板片内产生的偏应力已通过假设相简单连接而不是包含一个相嵌入另一相的混合物进行建模。在这里，我们使用简化模型来解释如何将转换应变纳入连续模型，然后我们使用简化模型定量解释现有板坯模型预测的不合理的大偏应力的起源。我们回顾了关于单晶样品转变的实验，并认为它们与晶粒尺度上偏应力的发生一致，这些偏应​​力与那些板坯模型预测（错误地）存在于板坯尺度上的偏应力相当。使用一个简单的例子，我们表明，虽然在晶粒尺度上可能存在较大的偏应力，但它们在包含许多晶粒的样品上的平均值可能是流体静力学的。这将我们引向了对微观结构进行建模的问题。我们概述了热...