Cold-formed beams from wood sawdust and veneer chips, energy characteristics

The paper presents the material, design, and energy characteristics of cold-formed wood-based composite beams made of sawdust and veneer chips with varying PVAc adhesive content. The study aimed to determine the influence of the macrostructure of the raw material and the manufacturing technology on the fracture mechanism, energy dissipation capacity, and functional mechanical quality of the material. The experimental research included three-point bending tests and fracture surface analysis, supplemented by the evaluation of energy parameters, including fracture energy, specific energy absorption, fracture surface area, and cumulative dissipated energy. In parallel, numerical models were developed and calibrated using the XFEM method, enabling the description of fracture initiation and stable propagation in terms of energy. A significant nonlinear effect of binder content on fracture behavior and energy dissipation capacity was found, with an optimal range in which energy parameters are maximized. Sawdust composites were characterized by higher total energy dissipation and a more extensive fracture process zone, while wood chip composites showed clear gap bridging effects. The presented results provide a new basis for the design of low-energy, sustainable structural composites from wood waste, especially for applications requiring high fracture resistance and energy dissipation, such as sandwich panel cores and hybrid structural components.