Prediction of Critical Buckling Load on Open Cross-Section Columns of Flax/PLA Green Composites

Abstract

The present work aims to analyze the buckling behavior of nonlinear elastic columns with different open cross-sections and slenderness ratios to verify the limits of the modified Ludwick law to predict the critical buckling load. The results of the analytical formulation based on the modified Ludwick law are compared with a FEM numerical model using the Marlow hyperelastic behavior and experimental results conducted on flax/PLA specimens with three different open cross-sections. The comparative results show that the numerical predictions agree with the experimental results in all the cases. The FEM model can exactly reproduce the buckling behavior of the C-section columns. However, the prediction errors for the C90 and C180 columns are higher than for the C60 columns. Moreover, the theoretical estimations indicate that the C90 cross-section column is the limit of application of the modified Ludwick law to predict the critical buckling load of nonlinear elastic columns with open cross-sections, and the C180 column is out of the prediction limits. Generally, the numerical and theoretical models underestimated the scattering effects of the predictions because more experimental variables were not considered by the models.

Degradation of Mechanical Properties of Flax/PLA Composites in Hygrothermal Aging Conditions

“…The fiber–weight ratio was 60% (see Figure 1 ). A more detailed description of the manufacturing process can be found in previous work [ 22 ].…”

“…The fiber-weight ratio was 60% (see Figure 1). A more detailed description of the manufacturing process can be found in previous work [22]. For the plasma-treated samples, an additional preparation process was carried out before manufacturing.…”

“…Rubio et al [ 18 ] demonstrated that flax/PLA biocomposites can absorb more energy than CFRPs while their specific compressive strength after impact was higher. Moreover, Jiao-Wang et al [ 19 , 20 ] showed that flax/PLA specimens can be a promising solution for energy absorption structures in the automotive industry and for slender beams subjected to buckling loads [ 21 , 22 ]. Nonetheless, they still need further research to prove their feasibility for industrial applications because the behavior of this green composite under aging tests has not been analyzed.…”