An Extension of the Strain Transfer Principle for Fiber Reinforced Materials

TL;DR

This paper extends the strain transfer principle for fiber reinforced materials by incorporating a finite element model of the fiber to improve strain measurement accuracy in soft matrix materials.

Contribution

It introduces a finite element-based extension of the strain transfer principle that accounts for the fiber's elastic properties, enhancing accuracy for soft matrices.

Findings

Finite element model improves strain prediction accuracy.

Extension is computationally efficient.

Better understanding of fiber-matrix interaction.

Abstract

Fiber optical strain sensors are used to measure the strain at a particular sensor position inside the fiber. In order to deduce the strain in the surrounding matrix material, one can employ the strain transfer principle. Its application is based on the assumption that the presence of the fiber does not impede the deformation of the matrix material in fiber direction. In fact, the strain transfer principle implies that the strain in fiber direction inside the fiber carries over verbatim to the strain inside the matrix material. For a comparatively soft matrix material, however, this underlying assumption may not be valid. To overcome this drawback, we propose to superimpose the matrix material with a one-dimensional model of the fiber, which takes into account its elastic properties. The finite element solution of this model yields a more accurate prediction of the strain inside the fiber in fiber direction at low computational costs.