Numerical Simulation Of Impact Damage Of Flax Fabric

Compared with inorganic fibers such as glass fibers,natural flax fiber composites have high specific mechanical properties,low density,low cost,strong sustainability,biodegradable and other characteristics,which can be used as an ideal reinforcing material for green composites.With its application in mechanical structural parts as well as impact resistant parts has become a research hotspot.In this study,flax fiberreinforced polypropylene composites are selected as the object of study,and their mechanical properties and impact resistance are studied and predicted through theoretical analysis,numerical simulation and experimental research,which include the following aspects:（1）A multi-scale finite element numerical simulation model of flax fiber fabric composites is constructed based on the progressive damage theory and homogenization method to study the damage intrinsic relationship and damage criterion of flax fiber fabric composites.The study focuses on the effect of flax yarn twist on the mechanical properties of composite materials,and the reliability of the multi-scale simulation model is verified with experiments,which finally provides material parameters to support the numerical simulation of low-velocity impact damage failure of flax fiber fabric composites.（2）The low-velocity impact damage behavior of flax fabric-reinforced composites was studied by both experimental and finite element simulation methods.The impact energy effect on the damage morphology of flax fabric composite laminate is studied by applying drop hammer impact test;finally,the low-velocity impact damage behavior of flax fabric composite is simulated in ABAQUS,and a finite element simulation model is established to effectively predict the complex damage evolution of flax fabric reinforced composite under low-velocity impact loading.（3）Taking flax fiber plain fabric reinforced polypropylene composites as the research object,the damage failure forms of the composites are different due to their different engineering elastic constants under different twist back angles.The low-speed impact damage behaviors of flax fiber fabric composites with different twist degrees under different impact energies are simulated in ABAQUS,and the effects of yarn twist on the impact resistance of flax fiber fabric composites are analyzed through the simulation results.This research establishes a finite element simulation model that effectively predicts the complex damage evolution of flax fiber fabric composites under low-velocity impact loading,and reveals the influence law of flax fabric under different twist degrees on the impact resistance of flax fiber reinforced polypropylene composites.The research results lay the theoretical foundation for the development and application of green,low-cost,impact-resistant flax fiber textile composites,and promote the application of this composite material in automotive,aerospace,rail transportation and other industries.