Research On The Forming And Experiment Platform Of 3D Rotary Braided Composites

3D braided composites having a spatial network structure inherits the advantages of the traditional composite material with high specific strength, high specific modulus, so they have good impact resistance, higher damage tolerance and energy absorption rate,has its great potential in aerospace. It has been widely used in foreign countries, although there have appeared part of three-dimensional braided composite applications in our country recently, but there have many shortcomings, such as small range of applications, lack of fabric structure, low automation of equipment and braiding efficiency.Drogue components formed by three-dimensional braided technology is aimed in this thesis. 3D rotary braiding is chosen to be forming method by comparing several current braiding crafts who have been often used. And then, selecting a solution which has large quantities of yarn carriers and varieties of path to design the structure of the 3D braiding machine.The mathematical model of the arrangement of the moving parts on the chassis is built to study the positional relationship of moving parts on the chassis, analysis the determinants of the track of yarn braider, and give its mathematical representation and algorithm. By analyzing the braiding process of the fabric, interwoven conditions of yarn is obtained in the design to establish the contact between yarn path and fabric structures. In addition, applying control volume element method to analyze fabric structure of specific movement on a specific arrangement, give the relationship between the parameters of fabric structure, and establish the relationships between fabric size and process parameters. The structure composition of the fabric is analyzed based on unit cell model, and the factor determining the fabric size and the braiding process of drogue are discussed.For drogue fabric, track algorithms and unit cell model above is applied to analyze spatial location of the yarn axis in the braiding movement, and obtain the feature point axis in the fabric. The points is adopted by cubic B-spline curve to approach the bending status of the yarn. By exporting this points to 3D modeling software, the static solid models of the fabric is established.According to the scheme of three-dimensional braiding machines in this thesis, an experiment platform and the control system accorded is built. The experiment has been carried out to verify the braiding process and machine as this thesis refer to.