Design of a composite sub-structural beam specimen for investigating tunneling cracks under cyclic loading

The design of a thin-walled composite beam is presented whose purpose is to facilitate the study of intra-laminar tunneling cracks at the sub-structural length-scale. The beam utilizes a variable thickness reinforcement in the longitudinal direction to develop a gauge zone of near-uniform strains when loaded in a cantilever beam configuration. The beam is manufactured from E-glass fibers and epoxy resin and is tested under static and cyclic multi-axial loading. The results presented include experimental strain measurements at the gauge zone, which agree with numerical strain predictions, and observations of the developed tunneling cracks.

Automated summary

This paper presents the design of a thin-walled composite beam for studying intra-laminar tunneling cracks at a sub-structural length-scale. The beam uses a variable thickness reinforcement in the longitudinal direction to create a gauge zone with near-uniform strains when loaded in a cantilever beam configuration. The experimental results, including strain measurements and observations of tunneling cracks, agree with numerical predictions.