Viscoelastic characterization and numerical simulation of poplar-bismuth oxide composites

QIN Yiting; YAN Jin; ZHANG Liqiang; LUO Hong; WU Qingding; YU Jianwu; XIE Zhijie; ZHANG Zonghao

doi:10.13732/j.issn.1008-5548.2025.03.011

Abstract：Objective This study investigates the effect of the composition of poplar wood processing residue powder and bismuth oxide on the viscoelasticity of poplar-bismuth oxide composites,aiming to optimize their application in fields such as furniture engineering. Methods Poplar wood residue powder and bismuth oxide powder were mixed using a warm-press forming method to prepare poplar-bismuth oxide composites with different particle sizes.Compression creep experiments were carried out on each sample under a constant load of 2 000 N,the real-time creep displacements were recorded.The elastic moduli were calculated from the stress-strain relationship to analyze composite viscoelasticity.The shear relaxation moduli were calculated based on the linear viscoelastic theory.The Kelvin-Voigt model and generalized Maxwell model were employed to establish viscoelastic models of the composites.Using optimization software 1stOpt,the elastic relaxation moduli were optimally fitted,and the corresponding shear modulus components(Gq)and shear relaxation time components(τq)were incorporated into the MSC Marc software for finite element simulation.This approach predicted the viscoelastic behavior of the composites and generated numerical simula-tion results of real-time creep displacement,which were then compared with the experimental results to evaluate consistency. Results and Discussion The poplar-bismuth oxide composites prepared via the warm-press forming method exhibited different creep behaviors and distinct viscoelastic properties depending on the particle size of the wood powder.By adjusting the propor-tion of wood powder with different particle sizes,the creep resistance of the composites was improved.When the mass ratio of poplar powder to bismuth oxide powder was 9∶1,the composites exhibited minimal creep deformation and the highest creep resistance.Further improvements in creep resistance were achieved by optimizing the ratio of wood powder with particle sizes≤425 μm and ≤180 μm.The optimal creep performance was observed when the ratio of ≤425 μm to ≤180 μm wood powder was 1∶1,resulting in minimal strain.Comparison of the compression creep experiment results with the numerical simulation results from MSC Marc showed strong consistency,indicating that the generalized Maxwell model accurately characterized the viscoelas-tic behavior of poplar-bismuth oxide composites.After the first instantaneous deformation stage,the displacement curve stabi-lized,demonstrating that short-term creep data can effectively predict the long-term creep behavior of the composites under dif-ferent shapes and working conditions. Conclusion Poplar-bismuth oxide composites prepared using the warm-press forming method exhibit excellent creep resistance and significant viscoelastic properties.The generalized Kelvin-Voigt and Maxwell models provide accurate constitutive models of the viscoelastic behavior based on optimal fitting of the creep experimental data.The particle size of the wood powder signifi-cantly affects the creep behavior of the composites,with the best creep resistance observed when the mass ratio of ≤425 μm to ≤180 μm wood powder is 1∶1.Additionally,the composites possess good color properties,making them a viable substitute for precious woods in the production of high-end automotive interior parts.These composites show great potential in construction and furniture engineering.This study offers new insights into the composition design and mechanical characterization of wood powder-metal oxide composites and other wood-based composites.The strong consistency between experimental and simulation results verifies the accuracy of the viscoelastic parameters and finite element models.Moreover,short-term creep data can reli-ably predict the long-term creep behavior of the composites,providing a reliable approach for evaluating the performance of com-posite structural components and products.