This study presents a novel approach for reconstructing all stress components of the dynamic axisymmetric fields of a soft material using photoelastic tomography (PT) and a high-speed polarization camera. This study focuses on static and dynamic Hertzian contact as an example of transient stress field reconstructions. For the static Hertzian contact (a solid sphere pressed against a gel block), all stress components in the urethane gel, which has an elastic modulus of 47.4 kPa, were reconstructed by PT using the measured photoelastic parameters. The results were compared with theoretical solutions and showed good agreement. For the dynamic Hertzian contact (a sphere impacting gel), a high-speed polarization camera was used to reconstruct the transient stress field within the gel. PT was used to quantitatively measure the shear and axial stress waves and showed different propagation speeds on the substrate. The technique allowed the simultaneous measurement of stress fields ranging from to kPa during large deformations, demonstrating its accuracy in capturing rapidly changing stress tensor components in dynamic scenarios. The scaling laws of the calculated impact force agreed with theoretical predictions, validating the accuracy of PT for measuring dynamic axisymmetric stress fields in soft materials.

中文翻译：

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软材料中轴对称应力场的高速光弹性断层扫描：所有应力分量的时间演化

这项研究提出了一种使用光弹性断层扫描（PT）和高速偏振相机重建软材料动态轴对称场的所有应力分量的新方法。本研究重点关注静态和动态赫兹接触作为瞬态应力场重建的示例。对于静态赫兹接触（实心球压在凝胶块上），弹性模量为 47.4 kPa 的聚氨酯凝胶中的所有应力分量均通过 PT 使用测量的光弹性参数进行重建。结果与理论解进行了比较，结果吻合良好。对于动态赫兹接触（球体撞击凝胶），使用高速偏振相机重建凝胶内的瞬态应力场。 PT 用于定量测量剪切应力波和轴向应力波，并显示出基材上不同的传播速度。该技术允许在大变形期间同时测量从 到 kPa 的应力场，证明了其在动态场景中捕获快速变化的应力张量分量的准确性。计算得出的冲击力的比例定律与理论预测一致，验证了 PT 测量软材料动态轴对称应力场的准确性。