Parallel-plate compression of multicellular spheroids (MCSs) is a promising and popular technique to quantify the viscoelastic properties of living tissues. This work presents two different approaches to the simulation of the MCS compression based on viscoelastic solid and viscoelastic fluid models. The first one is the standard linear solid model implemented in ABAQUS/CAE. The second one is the new model for 3D viscoelastic free surface fluid flow, which combines the Oldroyd-B incompressible fluid model and the incompressible neo-Hookean solid model via incorporation of an additional elastic tensor and a dynamic equation for it. The simulation results indicate that either approach can be applied to model the MCS compression with reasonable accuracy. Future application of the viscoelastic free surface fluid model is the MCSs fusion highly-demanded in bioprinting.

中文翻译：

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多细胞球体压缩的数值模拟：粘弹性流体与粘弹性固体

多细胞球体 (MCS) 的平行板压缩是一种很有前途的流行技术，用于量化活组织的粘弹性。这项工作提出了两种不同的方法来模拟基于粘弹性固体和粘弹性流体模型的 MCS 压缩。第一个是在 ABAQUS/CAE 中实现的标准线性实体模型。第二个是 3D 粘弹性自由表面流体流动的新模型，它通过加入额外的弹性张量和动态方程将 Oldroyd-B 不可压缩流体模型和不可压缩新胡克固体模型相结合。仿真结果表明，任何一种方法都可以以合理的精度对 MCS 压缩进行建模。