Structural Design Optimization And Mechanical Property Analysis Of T-shaped Three-dimensional Woven Fabric

The three-dimensional weaving method is an effective method for preparing complex cross-section prefabricated bodies and special-shaped structural parts.The use of woven Tbeams can overcome the seams and structural defects between the reinforcing ribs and the bottom panel of the two-dimensional layered T-beams,and can achieve one-time Forming a continuous multi-rib overall structure.Three-dimensional weaving molding introduces fibers or yarns through the thickness direction of the fabric to improve the mechanical strength and delamination resistance of the T-beam.Therefore,it is very practical to develop a continuous T-shaped three-dimensional integral woven fabric forming technology.It has broad application prospects as a reinforcement to prepare T-beam composite materials.This paper is based on the research on the structural design and forming technology of the three-dimensional T-shaped woven fabric preform,and the impact resistance and bending stiffness of the composite material are analyzed.The main research work in this paper includes:(1)The weaving requirements and performance requirements of the three-dimensional fabric are obtained through the analysis of the warp and weft weaving and weaving principle of the three-dimensional fabric with special-shaped structure,and the let-off mechanism and crimping mechanism of the loom are optimized and improved to effectively control the warp tension and reduce the Yarn wear,improving weaving efficiency and fabric forming quality.(2)Design and weave a three-dimensional woven fabric with a weft T-structure based on polyester fiber as the raw material.With the orthogonal weave as the basic structure,the number of yarns and the number of layers of warp and weft yarns in each area of the T-structure fabric are calculated,and the warp and weft yarns are reasonably allocated.According to the wiring rules,a T-structure integral woven fabric forming technology with continuous multi-rib in the warp direction is developed,and the T-structure preforms of single,double and triple ribs of specific sizes are woven.(3)Optimize the structure of the warp continuous T-shaped integral woven fabric,weave a T-structure fabric with binding warp yarns spanning different weft yarn rows,and measure the dimensions of the reinforcing ribs and the bottom panel.The results show that in a complete weave cycle,when the binding warp yarn spans two weft yarn rows,the surface flatness and formability of the T-structure woven fabric are better,and the size of each area is closer to the design of the theoretical parameters.(4)The woven preform is cured and molded by vacuum-assisted resin transfer molding to obtain a composite product.(5)Through the low-speed impact and bending performance tests of the single-rib T-structure three-dimensional woven fabric composites in the warp and weft directions,the results show that: The properties of the two T-structure composites are significantly different.The number of reinforcing fibers in the meridional T-structure is larger,the fiber volume content is larger,and the impact damage performance is better under impact load;(6)Under the same initial energy,the low-speed impact and bending properties of meridional single reinforcement,double reinforcement and three reinforcement T-structure composites are tested.The results show that the energy absorption effect of single reinforcement plate and three reinforcement plate is more than 95%;The impact load of three reinforcement T structure is the largest,and the bending stiffness and fracture toughness are also strong.Finally,the forming technology of T-structure three-dimensional integral woven fabric and the properties of composite materials are summarized and analyzed,and the future research direction is proposed.