Numerical Simulations of Azobé/Urea Formaldehyde Wood Plastic Composite Behaviors under Charpy Impact and Low-Velocity Drop Weight Tests

This work is concerned with the study of the influence of impactor’s velocity parameters, impactor’s geometry, the target plate properties, and thickness, on the response of a tropical wood plastic composite (WPC) Azobé/urea formaldehyde (Az/UF) plate under impact loading. Variations of the impact force, displacement, deformation, and impact energy of the specimens with weight fractions of 10, 20, 30, 40, and 50% have been considered in finite element analysis (FEA) simulations. The simulations of the Charpy and of a drop weight impact test on the WPC were carried out using the explicit dynamics module of ANSYS Workbench, which handles problems of dynamic loading of a short duration for 2D and 3D analyses. Contact laws that account for the compressibility of the interacting bodies (the standard steel impactor and the WPC target plate), have been used. The results show that the displacements decrease in contrast to the increase of the wood filler content, and vary in the 6.8–9.0 mm interval. From an energetic point of view, it is observed that the maximum absorbed energy is between 40 and 50% for the Azobe flour wt.%, with energy absorption rates of 28% and 26% of the total energy. These results are in agreement with those reported in previous experimental investigations on hybrid WPCs filled with wood flour and glass fibers, which produce an energy absorption rate of 24–26%. These results promote the applicability of Azobé tropical wood in fabricating WPCs for impact loading situations

Manufacture and Characterization of Cola Lépidota Reinforcements for Composite Applications

This study represents the first works on the manufacture of reinforcements for composite applications such as yarns and fabrics using a tropical fiber extracted from the bast of the Cola Lepidota (CL) plant. Different types of products were produced, including twisted and untwisted yarns and woven and quasi-unidirectional fabrics to manufacture composite samples. At each scale, experimental characterizations of textile and mechanical properties were carried out; these properties are compared to those given in the literature concerning natural fiber materials. The results show that the tenacity of twisted and untwisted CL yarns is higher than that of similar products based on flax fibers, which is an important result for the weaveability of these rovings. At the fabric scale, the quasi-unidirectional architecture reduces waviness and shows promising tensile properties compared to woven fabrics. On the scale of composites, these developments made it possible to achieve properties in tensile comparable, particularly in stiffness, to those achieved by composites based on natural fibers. The objectives of this paper are to highlight the advantages and drawbacks of different types of reinforcements, and to present the first characterization of the properties of products based on CL fibers

Characterization of Tensile Properties of <i>Cola lepidota</i> Fibers

Plant fibers are being increasingly explored for their use in engineering polymers and composites, and many works have described their properties, especially for flax and hemp fibers. Nevertheless, the availability of plant fibers varies according to the geographical location on the planet. This study presents the first work on the mechanical properties of a tropical fiber extracted from the bast of Cola lepidota (CL) plant. After a debarking step, CL fibers were extracted manually by wet-retting. The tensile properties are first identified experimentally at the fibers scale, and the analysis of the results shows the great influence of the cross-section parameters (diameter, intrinsic porosities) on these properties. Tensile properties of CL fibers are also predicted by the impregnated fiber bundle test (IFBT). At this scale of bundles, a hackling step, which reduces shives and contributes to the parallelization of the fibers within bundles, improves tensile properties predicted by IFBT. The comparison with the properties of plant fibers given in the literature shows that CL fibers have tensile properties in the same range as kenaf, flax or hemp fibers

Manufacture and Characterization of Cola Lépidota Reinforcements for Composite Applications

This study represents the first works on the manufacture of reinforcements for composite applications such as yarns and fabrics using a tropical fiber extracted from the bast of the Cola Lepidota (CL) plant. Different types of products were produced, including twisted and untwisted yarns and woven and quasi-unidirectional fabrics to manufacture composite samples. At each scale, experimental characterizations of textile and mechanical properties were carried out; these properties are compared to those given in the literature concerning natural fiber materials. The results show that the tenacity of twisted and untwisted CL yarns is higher than that of similar products based on flax fibers, which is an important result for the weaveability of these rovings. At the fabric scale, the quasi-unidirectional architecture reduces waviness and shows promising tensile properties compared to woven fabrics. On the scale of composites, these developments made it possible to achieve properties in tensile comparable, particularly in stiffness, to those achieved by composites based on natural fibers. The objectives of this paper are to highlight the advantages and drawbacks of different types of reinforcements, and to present the first characterization of the properties of products based on CL fibers

Characterization of Tensile Properties of Cola lepidota Fibers

Plant fibers are being increasingly explored for their use in engineering polymers and composites, and many works have described their properties, especially for flax and hemp fibers. Nevertheless, the availability of plant fibers varies according to the geographical location on the planet. This study presents the first work on the mechanical properties of a tropical fiber extracted from the bast of Cola lepidota (CL) plant. After a debarking step, CL fibers were extracted manually by wet-retting. The tensile properties are first identified experimentally at the fibers scale, and the analysis of the results shows the great influence of the cross-section parameters (diameter, intrinsic porosities) on these properties. Tensile properties of CL fibers are also predicted by the impregnated fiber bundle test (IFBT). At this scale of bundles, a hackling step, which reduces shives and contributes to the parallelization of the fibers within bundles, improves tensile properties predicted by IFBT. The comparison with the properties of plant fibers given in the literature shows that CL fibers have tensile properties in the same range as kenaf, flax or hemp fibers