A staged modeling approach is proposed to divide the needling process into three stages:deformation,insertion and smoothness,and construct dynamic coupling models of rigid force,cutting force and friction force respec...A staged modeling approach is proposed to divide the needling process into three stages:deformation,insertion and smoothness,and construct dynamic coupling models of rigid force,cutting force and friction force respectively.Based on the Boussinesq contact theory,the initial tip-fabric contact behavior is analyzed,combined with the elastic cutting theo-ry to quantify the fiber breakage mechanism,and the Winkler foundation model and LuGre dynamic friction model are used to characterize the friction properties of the needle shaft.It is shown that:the stiffness force in the deformation stage is af-fected by the geometrical parameters of the needle tip and the elastic modulus of the fabric;the cutting force in the insertion stage is closely related to the micro deformation of the fiber;and the dynamic friction behavior in the smooth stage can be depicted by the LuGre model with high accuracy.The complete needling force prediction model finally established provides a theoretical basis for optimizing composite needling process parameters,reducing fiber damage and equipment design.展开更多
文摘A staged modeling approach is proposed to divide the needling process into three stages:deformation,insertion and smoothness,and construct dynamic coupling models of rigid force,cutting force and friction force respectively.Based on the Boussinesq contact theory,the initial tip-fabric contact behavior is analyzed,combined with the elastic cutting theo-ry to quantify the fiber breakage mechanism,and the Winkler foundation model and LuGre dynamic friction model are used to characterize the friction properties of the needle shaft.It is shown that:the stiffness force in the deformation stage is af-fected by the geometrical parameters of the needle tip and the elastic modulus of the fabric;the cutting force in the insertion stage is closely related to the micro deformation of the fiber;and the dynamic friction behavior in the smooth stage can be depicted by the LuGre model with high accuracy.The complete needling force prediction model finally established provides a theoretical basis for optimizing composite needling process parameters,reducing fiber damage and equipment design.
