Investigation on the mechanical property of fiber reinforced recycled composite wood and its constitutive model

To improve wood utilization in the field of construction engineering, a fiber reinforced recycled composite wood was successfully prepared using waste wood, polypropylene and polyester fiber in this work. The polypropylene was utilized as a hot melt adhesive and the fiber was employed as a lashing bundle, which both enhance the mechanical property of the composite wood. The flexure performance of the composite wood was tested and its constitutive model was established for analyzing its stress–strain characteristics. The results show that the waste wood combined with polypropylene and fiber can be recycled as a serviceable composite, and its flexural strength and flexural stiffness were elevated by approximately 54% and 20%, respectively. The strength defect in the tension zone of the recycled wood was improved and its compression zone can enter the plastic stage thus improving its force coordination. The constitutive model of the composite wood was established based on the Hill Criterion and 3D-Hashin Criterion. The simulation method proposed can accurately predict the mechanical behavior and failure process of composite wood during bending, and its yield trend and damage process are close to actual experiments, which was used to reveal the strengthening mechanism of polypropylene and fiber on the wood.