FEM Simulation Of 3D Angle Interlock Woven Composite Under Ballistic Impact At Unit Cell Scale

As one of 3D woven composite,3D angle-interlock woven composite (3DAWC) has higher fracture toughness and delamination resistance than that of laminated composite because of yarns run through thickness direction. Three-dimensional angle-interlock woven composite is more attractive in engineering owing to the 3D angle-interlock woven fabric can be manufactured in a traditional loom with high efficiency. Angle interlock weaving is a technique in which yarns are placed at an angle to the thickness direction to resist delamination. Three-dimensional interlock wove fabric can be classified into two types, referred as layer to layer angle interlock woven fabric and through-thickness angle interlock woven fabric. It is valuable to study the ballistic behavior of the 3D angle-interlock composites because of the wide potential applications in engineering, especially in the case of impact loading condition.Unit cell model that based on the microstructure of the 3D angle interlock woven composite was established to investigate impact deformation and damage. In the unit cell model, the composite was simplified into a combination of resins, weft yarns and warp yarns to define the stiffness matrix and failure evolution of the material. VUMAT (FORTRAN vectorized user-material) subroutine which based on the unit cell model has been developed and connected with commercial FEM code ABAQUS to calculate the ballistic impact damage and energy absorption of the composite. The experimental and FEM results of residual velocities of the projectile, and damages of the composite target were compared. Good agreement between experimental and theoretical proves the unit cell model and the VUMAT subroutine are reasonable for ballistic performance design of the 3D angle interlock woven composite.The main researches conducted are as follows:(1) 3D angle interlock woven fabric with Twaron (PPTA) fiber tows was designed to manufacture in a tradition loom. Unsaturated polyester resin was injected into the 3D angle-interlock woven fabric with Vacuum assisted resin transfer molding (VARTM) technique.(2) A series of ballistic impact experiments were conducted. The strike and residual velocities of the projectiles were measured to calculate strike velocity vs. residual velocity curves. The impact damage morphologies were photographed to reveal the impact damage mechanisms.(3) Based on unit-cell model of the 3D angle interlock woven composites and critical damage area (CDA) criteria, a user-defined materials subroutine was established. VUMAT (FORTRAN vectorized user-material) connected with commercial FEM code ABAQUS to calculate the impact damage evolution and energy absorption of the composite. The experimental and FEM results of residual velocities of the projectile, and damages of the composite target were compared. These are good agreements between experimental observation and FEM calculation.The results provide the design methodology of the 3D angle interlock woven composite in ballistic protection. With the scheme, the high performance ballistic armor could be design effectively.