Design And Manufacture Of 3D Orthogonal Composite Panels And Its Low-Velocity Impact Mechanical Performance Research

Fiber reinforced composite material as a representative new material,due to its advantages of light weight and high strength,has gradually replaced metal materials to become the breakthrough focus of China's manufacturing transformation.At present,the fiber reinforced composites which are widely used in civil and industrial fields are mainly composed of traditional two-dimensional fiber reinforcement and resin matrix.During their manufacture and service lifetime,impact events from tools drop or gravel are inevitable.Different from metal materials,the damage forms of two-dimensional fiber composites are mostly internal delamination damage when they are subjected to lowervelocity impact.This kind of damage is difficult to be observed on the surface in sight,but it is easy to introduce great damage to the performance of the component and seriously affect its reliability.Three-dimensional fiber reinforcement with extra yarns in thickness direction have been proved to have better impact resistance because the development of delamination is hindered by Z-yarns.In addition,the stress distribution in the thickness direction of the material is asymmetric under low velocity impact,and the ability of any single yarn to resist different stresses is not equaled.Therefore,the use of different yarn combinations in the direction of thickness can further improve the impact resistance of the components,avoid the performance defects of single yarn effectively,and meet the specific performance requirements.This paper focus on assesses the synergistic effect of3 D orthogonal woven structure and asymmetric carbon/glass hybridization on the low velocity impact performance of composites.In this paper,two kind of woven,a two-dimensional unidirectional woven and a three-dimensional orthogonal woven,with asymmetric mixture of carbon fiber and glass fiber were designed.Then,based on the designed fabric structure and the traditional twodimensional loom weaving principle,a prototype of the three-dimensional loom was designed and the construction of the lower-level machine system and the compilation of the lower-level machine software were completed.The hybrid two-dimensional woven and the hybrid three-dimensional woven were fabricated on the 3D loom prototype,and the all woven were cured by vacuum assistant resin transferring mold process.The low velocity impact test of 30.9J was carried out on the all composite plates.In order to reduce the impact of weaving factors on the impact performance,the impact surface is changed to substitute the different structures of yarn hybrid.The impact responses of the materials were studied by the damage morphology and mechanical curves.The results show that the hybrid three-dimensional orthogonal composite has better impact resistance.The three-dimensional orthogonal composite with Z yarns to provide strength support in the thickness direction does not change the overall structure when subjected to an impact event.However,the two-dimensional unidirectional composite has severe delamination damage,which in turn causes the material stiffness to decrease and the load-bearing capacity to deteriorate.In addition,the glass fiber on the non-impacted side showed greater deformability because of the lower modulus of glass fiber.In order to further analyze the synergistic effect of 3D orthogonal woven structure and yarn hybridization on the low velocity impact performance of the composite,a wider range of impact level tests were carried out on the two surfaces of the composite.In addition to the damaged morphology observation and mechanical curve,Meso-level(yarn)finite element models including the failure criterion and progressive damage law were established in ABAQUS/Explicit to compare the structure deformation and damage behavior.The impact side has a significant effect on the failure mode of hybrid threedimensional orthogonal composites.The failure modes of the glass fiber side impact sample are the delamination of the carbon fiber layer on the non-impact side and the subsequent tensile failure of the carbon fiber,while the failure modes of the carbon fiber side impact sample are mainly the crushing failure of the carbon yarns on the impact side and the large area debonding between fiber and the resin matrix on the surface.This makes the composite structure of carbon fiber located on the impact side exhibit better impact resistance relative to the penetration threshold energy.