Journal of Textile Research ›› 2020, Vol. 41 ›› Issue (11): 150-155.doi: 10.13475/j.fzxb.20200301506

• Machinery & Accessories • Previous Articles     Next Articles

Method for testing natural frequency of weft knitting needles in free state

DAI Ning, PENG Laihu(), HU Xudong, CUI Ying, ZHONG Yaosen, WANG Yuefeng   

  1. Key Laboratory of Modern Textile Machinery & Technology of Zhejiang Province, Zhejiang Sci-Tech University,Hangzhou, Zhejiang 310018, China
  • Received:2020-03-06 Revised:2020-07-29 Online:2020-11-15 Published:2020-11-26
  • Contact: PENG Laihu E-mail:laihup@zstu.edu.cn

Abstract:

The natural frequency characteristics of knitting needles on weft knitting machines are closely related to the property of weft knitting machines. The existing weft knitting machine knitting needles are small, slender, and have variable cross-sectional diameter in their free state, and the characteristics of the knitting needles at various stages are difficult to test. This research made use of a small and low-quality piezoelectric zirconate titanate ceramics (PZT) attached to the surface of the knitting needle to form an adhesive body structure. A high-performance impedance analyzer was used to perform a frequency sweep test on the bonded body. According to the complex impedance and phase angle curves at different frequencies, the modes of each order in the PZT free state were obtained. ANSYS finite element simulation software was used to compare and verify each mode of knitting needles and bonded bodies, and analysis was performed based on the cantilever curvature, deflection theory, and knitting needle vibration theory. The results of theoretical calculation and simulation test show that this experimental test method is able to measure effectively the natural frequency of the needles in the free state.

Key words: weft knitting machine, knitting needle, complex impedance curve, phase angle curve, ANSYS finite element simulation, vibration characteristic

CLC Number: 

  • TS103.7

Fig.1

Simplified diagram of knitting needle movement during loop forming process of weft knitting machine"

Fig.2

Schematic diagram of overall design of the natural frequency of the knitting needle"

Fig.3

Cross-section structure of bonded body"

Fig.4

Diagram of experimental connection"

Fig.5

Principle of measuring natural frequency of bonded body by impedance analyzer"

Fig.6

Graph of complex impedance-frequency and angle-frequency. (a) Group 1; (b) Group 2"

Fig.7

Schematic diagram of surface curvature of knitting needles during bending"

Tab.1

Statistical table of the first three order frequency of sample 1 and 2Hz"

试样编号 一阶频率 二阶频率 三阶频率
1 342.4 734.0 957.8
2 361.1 790.0 976.5

Fig.8

First 3 orders of modal analysis results of knitting needle. (a) Order 1; (b) Order 2; (c) Order 3"

Tab.2

Summary of knitting needle simulation and test results error result"

模态 仿真
频率/
Hz
实验1 实验2
测试
频率/Hz
测试
误差/%
测试
频率/Hz
测试
误差/%
1 383.1 342.4 10.6 361.1 5.7
2 896.7 734.0 18.1 790.0 11.9
3 1 019.0 957.8 6.0 976.5 4.2

Fig.9

First 3 orders of modal analysis results of bonded body. (a) Level 1; (b) Level 2; (c) Level 3"

Tab.3

Summary of bonded body simulation and test results error result"

模态 仿真
频率/
Hz
实验1 实验2
测试
频率/Hz
测试
误差/%
测试
频率/Hz
测试
误差/%
1 382.0 342.4 10.4 361.1 5.5
2 885.5 734.0 17.1 790.0 10.8
3 986.4 957.8 2.9 976.5 1.0
[1] 张华. 纬编针织机编织动力学分析及控制策略研究[D]. 杭州:浙江理工大学, 2013: 30-39.
ZHANG Hua. Dynamic analysis of knitting process and its control strategy study of weft knitting machine[D]. Hangzhou: Zhejiang Sci-Tech University, 2013: 30-39.
[2] 张成俊, 游良风, 左小艳. 电脑横机织针的磁驱动设计与建模[J]. 纺织学报, 2019,40(9):180-185.
ZHANG Chengjun, YOU Liangfeng, ZUO Xiaoyan. Magnetic driving design and modeling for knitting needles of computerized flat knitting machine[J]. Journal of Textile Research, 2019,40(9):180-185.
[3] 刘永春, 赵艳影. 一种悬臂梁模态测试方法[J]. 力学与实践, 2019,41(5):572-577.
LIU Yongchun, ZHAO Yanying. A modal testing method for cantilever beam[J]. Mechanics in Engineering, 2019,41(5):572-577.
[4] 唐冶, 王涛, 丁千. 主动控制压电旋转悬臂梁的参数振动稳定性分析[J]. 力学学报, 2019,51(6):1873-1880.
TANG Ye, WANG Tao, DING Qian. Stability analysis on parametric vibration of piezoelectric rotating cantilever beam with active control[J]. Chinese Journal of Theoretical and Applied Mechanics, 2019,51(6):1873-1880.
[5] 陈春松. 多路数圆型纬编针织机控制系统设计[D]. 杭州:浙江理工大学, 2012: 2-28.
CHEN Chunsong. Design of control system for multi-route circular weft knitting machine[D]. Hangzhou: Zhejiang Sci-Tech University, 2012: 2-28.
[6] 马创军. 圣东尼SM8-TOP1型无缝内衣机多色提花的编织[J]. 针织工业, 2009(7):8-9.
MA Chuangjun. The knitting technology of multi-color jacquard on the Santoni SM8-TOP1-type seamless underwear knitting machine[J].Knitting Industries, 2009(7):8-9.
[7] 龙海如. 针织学[M]. 北京: 中国纺织出版社, 2008: 1-26.
LONG Hairu. Knitting Textiles[M]. Beijing: China Textile & Apparel Press, 2008: 1-26.
[8] DURU S C, CANDAN C, MUGAN A. Effect of yarn, machine and knitting process parameters on the dynamics of the circular knitting needle[J]. Textile Research Journal, 2015,85(6):568-589.
[9] LONG H R. The effect of the shape and parameters of the knitting needle on cam-to-needle impact forces[J]. Journal of The Textile Institute, 2000,91(2):259-267.
[10] 方园, 夏凡甜, 居婷婷, 等. 基于SolidWorks建模技术的双针筒电脑袜机成圈机件有限元仿真分析[J]. 纺织学报, 2012,33(9):135-142.
FANG Yuan, XIA Fantian, JU Tingting, et al. Finite-element simulation and analysis of double-cylinder computerized hosiery machine's knitting element based on Solidworks modeling technology[J]. Journal of Textile Research, 2012,33(9):135-142.
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