Analysis of Bending Loads on Bamboo-Balsa and Bamboo-Polypropylene Honeycomb Composite Sandwiches

Abstract

This research was done to evaluate the bending behavior (load-deflection curve and failuremode) of sandwich structures using Tali Bamboo strips as sandwich skin material. Bending tests wereconducted on sandwich specimens with end grain balsa (3-point bending) and polypropylene (PP)honeycomb cores (4-point bending) to evaluate their bending behavior. From the test results,analytical and numerical models were developed to simulate the observed bending behavior. Themodels are able to simulate the pre-failure bending behavior and failure modes (core shear failure) ofthe specimens. It is also shown that for thin (length/thickness > 20) sandwiches the models are moreaccurate since shear effects are less prominent. With the obtained models a predictive comparison isdone between the PP and balsa cored specimens since the testing configuration for each type wasdifferent. The analysis results show that balsa cored specimens are able to withstand higher transversebending loads due to the higher shear strength of the balsa core. These prediction results are to beproven by specimen testing which is the subject of future research.

Review of literature on eco-friendly sandwich structures made of non-wood cellulose fibers

“…Wu et al [242] calculated the elastic constant of sandwich structures with face sheets made of veneers and cores made of bamboo chips. An analytical/numerical/experimental study was conducted by Seno et al [243] to examine the bending behavior of renewable sandwich structures with bamboo strips face sheets and two types of core, namely, balsa and PP honeycomb. It was shown that the sandwich composites with a balsa core have an instant strength drop after failure, whereas those with a PP honeycomb core have a more gradual post-failure strength drop.…”

“…[238], [239] [149], [240], [241], [242], [243], [246], [247] [249], [250], [251], [252], [253], [254], [255] [256]…”