Experimental investigation on axial compression properties of bamboo winding thin-walled tubes under different winding angles

To explore the effect of the bamboo winding angle on the axial compression properties and failure modes of bamboo winding thin-walled tubes (BWTT), an axial compression test was conducted in this study. Seven distinct winding angles were considered. The micro-morphology of parenchyma cells, fibers, and epoxy resin was observed based on the scanning electron microscope (SEM) and computed tomography (CT). The micro failure mechanism of BWTT was revealed. The results show that the winding angle has a significant impact on the axial compression performance of BWTT. With the increase in the winding angle, the load-bearing capacity of BWTT declines, whereas its ductility improves. Additionally, six strength criteria were adopted to evaluate the compressive strength of BWTT, among which the Hankinson criterion (n = 2.33) demonstrated favorable applicability. The continuous strength method (CSM) was also adopted to predict the compressive strength of BWTT, and a good correspondence was observed between the predicted and test results. An axial stress-strain model of BWTT was proposed, which was based on the Ramberg - Osgood (RO) model and considered the angle influence parameters m theta and n theta. The model results agree well with test results and can provide a theoretical foundation for the application of BWTT.Highlights Winding angle has a significant impact on the axial compression properties of BWTT. The failure mechanism of BWTT was analyzed by SEM and CT. Hankinson criterion (n = 2.33) and CSM can predict the compressive strength of BWTT. Considering the winding angle, the compressive stress-strain model is proposed.