Three-dimensional modeling of the structure formation and consolidation of wood composites

Abstract

A new three-dimensional (3D) computer simulation model is proposed to study structure development in wood composites, particularly strand or short fiber wood composites. The model takes into account the stochastic positioning and orientation of the strands within the mat. It also predicts the response of individual strands within the structure to the compressive and shear forces produced during mat consolidation. The model provides a complete description of mat structure in three dimensions, including spatial distribution of porosity, inter-strand contact, and density. Predictions for porosity obtained with the 3D model compare very well with those from an earlier two-dimensional analytical model. Mat structure is dictated by mat density in a two-step process: rapid removal of macrovoids before the mat density reaches the original wood density and asymptotic elimination of microvoids at higher mat densification. Other factors of importance include original wood density and strand dimensions, particularly strand thickness and width. Although known for its influence on mechanical properties, strand orientation seems to have little effect on mat porosity and strand contact.

Impact of multilayering on the filtration performance of clean air filter media

“…[ 41 ] It was also generalized to describe wood‐fibre composites such as oriented strand‐boards. [ 42 ] In our study, fibres, approximated as straight cylinders, were deposited sequentially over the X‐Y plane. Fibre position and orientation were chosen based on a random uniform distribution, while the sequence of fibre diameters to be deposited was chosen either to create a multilayered or a uniformly distributed filter media (the latter hereinafter referred to as a well‐mixed filter medium).…”

Fabrication and Characterization of Thermal-Responsive Biomimetic Small-Scale Shape Memory Wood Composites with High Tensile Strength, High Anisotropy

“…Compared with plastics, steel, cement, and other structural material, wood has unique mesoporous and hierarchical structure stemming in its biological origin, which makes it inherit wood material characteristics such as high ratio of strength to weight, certain viscoelasticity, and anisotropy. The mesoporous structures that consist of pores in hardwood, lumina varying in diameter from 10 to 80 μm, pits, and gum canal or resin canal, which together form the interpenetrating cannular networks and offers the penetrability, accessibility, and reactivity of wood materials [1,2,3]. In the past few decades, bio-inspired intelligent responsive materials have become one of the most exciting fields in the research of new materials.…”