3-D computational model of poly (lactic acid)/halloysite nanocomposites: Predicting elastic properties and stress analysis

A real-structure based 3-D micromechanical computational model of poly (lactic acid) nanocomposites reinforced by randomly oriented halloysite nanotubes (HNTs) was developed and compared with an idealized model (conventional model) and experimental results. The developed idealized model consists of nanotubes with fixed aspect ratio and the proposed alternative real-structure based model takes the experimentally observed variations of HNTs sizes, impurities and aspect ratios into account. The requirements of the 3-D HNTs nanocomposite models have been explored by testing idealized, real structure based models, as well as models with hollow and solid cylinder-like reinforcements with varied amounts of HNTs. A unit cell model with cylindrical reinforcements (representing HNTs) and at least 30 inclusions gave promising results, provided the model includes actual information about HNT's size ranges and aspect ratios. Numerical studies were validated with experimental investigations and the developed real-structure based model gave more accurate results than idealized and analytical models.