scholarly journals Influence of technical parameters on the structure of annular axis braided preforms

2021 ◽  
Vol 28 (1) ◽  
pp. 160-168
Author(s):  
Xi Wang ◽  
Guoli Zhang ◽  
Xiaoping Shi ◽  
Ce Zhang

Abstract A modified vertical braiding machine and closed annular axis mandrels with a special-shaped cross section were used to braid annular axis preforms under four different technical parameters. After measuring the braiding angles and yarn spacing of the braided preform in different areas of the mandrels, it was found that the braiding angle increased by 20.9% and the yarn spacing decreased by 19.8% when the speed of the yarn carrier was doubled. The braiding angle decreased by 31.1% and the yarn spacing increased by 28.6% when the rotation speed of the mandrels was doubled. The results show that the rotation speed of the mandrel has a slightly greater influence on the braiding angle and the yarn spacing. By using the modified braiding machine to braid the annular axis preforms, multi-layer continuous braided preforms can be achieved on compact equipment. And the structure of the annular axis braided preforms can be changed by changing the technical parameters.

2011 ◽  
Vol 335-336 ◽  
pp. 1025-1028 ◽  
Author(s):  
Fan Ming Zeng ◽  
Guang Tian Zou ◽  
Jing He Liu

The Tm,Ho:BaY2F8 single crystal was successfully grown by the Cz method. The optimal technical parameters obtained are as follows: the pulling rate is 0.5—0.6mm/h; the rotation speed is 5—7rpm; the cooling rate is 10°C/h. The result of XRD curve shows that as-grown Tm,Ho:BaY2F8 laser crystal belongs to the monoclynicsystem and space group I41/a, the cell parameters calculated are: a = 0.69829 nm, b = 1.0519 nm, c = 0.42644 nm, β=99.676°, Z=2. Absorption spectra of Tm,Ho:BaY2F8 laser crystal at room temperature were measured and analysed, the absorption cross-section at 781nm calculated are 7.66×10-21cm-2.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Teng Li ◽  
Wenbin Dou

An edge slotted waveguide antenna array based on T-shaped cross-section radiating waveguide is proposed. The T-shaped waveguide is analyzed and designed to operate in dominant mode around the center frequency, which has a lower profile compared with the rectangular one. The radiating slots are etched and rotated alternatively on the broadened top plate without cutting into the adjacent walls. The metal fences are inserted between slots to reduce the mutual coupling and surface wave. Therefore, the sidelobe level in E-plane is well suppressed. A 2 × 8 antenna array working at Ka-band is designed and fabricated. The measured results agree well with simulations which demonstrate this novel waveguide structure.


2018 ◽  
Vol 416 ◽  
pp. 29-54 ◽  
Author(s):  
Andrew J. Hull ◽  
Daniel Perez ◽  
Donald L. Cox

2007 ◽  
Vol 54 ◽  
pp. 771-775
Author(s):  
Osamu KUNITA ◽  
Masatoshi YUHI ◽  
Junichi YAMAZAKI ◽  
Shinya KOTAKI ◽  
Hajime ISHIDA

2018 ◽  
Vol 284 ◽  
pp. 71-76
Author(s):  
P.V. Solovyev ◽  
A.I. Gomzin ◽  
L.A. Ishbulatov ◽  
S.N. Galyshev ◽  
F.F. Musin

In this article the results of stress-strain state investigation for composite airplane wing stringer with different layers stacking structures are presented. As an object of research, a stringer made of composite carbon with V-shaped cross-section is considered. Due to the stress-strain state analysis of various stringer structures, the most effective structure for stringer layers stacking is selected, both in the view of providing the most rigidity and optimal perception by the stringer the field of external loads, which are most typical for the conditions of its operation.


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