碳/玻混杂三维五向编织复合材料工字梁弯曲及失效行为OA

Three-dimensional(3D)five-direction braided glass/carbon hybrid I-beam composites were pre-pared by using 3D braiding technology and vacuum assisted resin transfer technology,the four-point bending exper-iments of I-beam composites with different hybrid proportions and different hybrid positions were conducted,and the stress distribution and damage process were analyzed using three-dimensional digital image correlation(3D-DIC)technology.The results show that the strength of 1/3 carbon fiber axis yarn and 2/3 carbon fiber axis yarn is only increased by 4.5％and 11.5％compared with that of glass fiber,and the different proportion of carbon fiber has little effect on the strength of I-beam composites.The bending failure modes of I-beam are different when the carbon fiber distribution is different.The two samples of pure glass and carbon fiber at the lower flange belong to the failure mode of edge fracture near the lower press head,while the two samples of carbon fiber at the web,web and lower flange belong to the failure mode of the front and back dislocation tilt of the web.The three samples of carbon fiber on upper flange,upper flange and lower flange,upper flange and web all belong to the failure modes of longi-tudinal fracture in the center of the web.Combined with load-displacement curve and failure mode analysis,the carbon fiber is more suitable for mixing in the upper flange.When 1/3 carbon fiber is distributed in the upper flange and 2/3 carbon fiber is distributed in the upper and lower flange,the strength and deformation resistance of I-beam are better.