Han X.,Xian Aerospace Composite Institute |
Wang X.,Xian Aerospace Composite Institute |
Wang Z.,Xian Aerospace Composite Institute |
Wang H.,Xian Aerospace Composite Institute |
And 2 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2015
Itaconic acid (IA) modified with different amounts of ammonia was copolymerized with acrylonitrile(AN), methyl acrylate(MA) and vinyl sulfonic acid(AS). The polymer solution was wet spined to prepare the precursor, then was carbonized to prepare the polyacrylonitrile(PAN) based carbon fiber(CF). The reaction rate, sectional morphology, orientation, glass transition temperature, thermal shrinkage and mechanical behavior of the precursor or CF were studied by the conversion measure, optical microscope, X- ray photoelectron spectroscopy (XPS), dynamic mechanical analyzer (DMA) and electronic tensile testing machine. For experimental results: IA is ammoniated to prepare the β-ammonium itaconate. The number average molecular, molecular weight distribution and contrast viscosity of the ammoniating PAN dope are about 64100, 2.98 and 1.86 respectively. The sectional morphology of the PAN precursor polymerized with β-ammonium itaconate is bright and perfect. The tensile strength and elastic modulus of the single precursor with 25% β-ammonium itaconate are about 6.8 cN/dtex and 113.0 cN/dtex respectively under the drafting rate of 12. The glass transition temperature of the precursor with 25% ammonification increases by 3.19℃. The tensile strength, elastic modulus and loop tenacity of CF(1K) prepared with the precursor are about 4572MPa, 249 GPa and 62.4 N respectively. ©, 2015, Chengdu University of Science and Technology. All right reserved.
Yan L.,Northwestern Polytechnical University |
Jiang W.,Xian Aerospace Composite Institute |
Shi Y.-Y.,Northwestern Polytechnical University
Yuhang Xuebao/Journal of Astronautics | Year: 2012
Based on the analysis of the working principle of rectification and the key factors affecting rectification control accuracy, the CCD (Charge Coupled Device) linear array image sensor is selected as the detecting element in this paper. Then, the actuator is made up of the stepper motor, the worm-and-wheel gear and the correction roller. Besides, a compound control strategy of FUZZY-PID is introduced in the controller. Finally, the rectification control system for tape winding is established. According to the experimental verification, the rectification accuracy fully meets the requirements of winding process, thus realizing the rectification automation.