Journal of Textile Research ›› 2020, Vol. 41 ›› Issue (12): 144-150.doi: 10.13475/j.fzxb.20200401207

• Machinery & Accessories • Previous Articles     Next Articles

Natural frequency characterization based on Euler-Bernoulli beam theory on knitting seamless underwear

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:2020-04-04 Revised:2020-07-29 Online:2020-12-15 Published:2020-12-23
  • Contact: PENG Laihu E-mail:laihup@zstu.edu.cn

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Abstract:

Aiming at the lack of theoretical models of natural frequencies of knitting needles in knitting seamless underwear and the difficulties in capturing needle vibration characteristics during knitting, Euler-Bernoulli beam theory was used to solve the vibration equation of knitting needles in the tangential direction of the cylinder to obtain the mode curve and natural frequency the knitting needle. ANSYS simulation was used to perform the model analysis on 6 needle exit positions on the second clear cam. The theoretical and numerical results are consistent and the relative error in calculating needle natural frequency is below 2.3%. The DIMAX series high-speed camera from German PCO company was used to obtain the lateral vibration curve of the knitting needles when they were forced to move along the triangular arc surface. The experimental results show that the natural frequency characteristics of the knitting needles can be accurately analyzed using the Euler-Bernoulli beam theory. The method of capturing the lateral vibration of the knitting needles involved in the experiment is of reference significance for the experimental research on the vibration characteristics of the knitting needles in circular weft knitting machines.

Key words: knitting needle, knitting process, natural frequency, vibration mode curve, Euler-Bernoulli beam theory, ANSYS simulation

CLC Number: 

  • TS103.7

Fig.1

Plane sketch of seamless underwear machine cylinder"

Fig.2

Constraint of needle in cylinder (a) and its cantilever (b) model"

Tab.1

Theoretical value of first order natural frequency of 6 needle positions"

出针长度/mm 27 28 29 30 31 32
第1阶频率/Hz 508 472 440 411 385 361

Fig.3

First third-order mode curves of needle"

Fig.4

Diagram of knitting needle simulation constraint. (a) Constraint from needle groove inner wall left side; (b) Constraint from needle groove inner wall right side; (c) Spring coil constraint; (d) Constraint from needle groove inner wall back side"

Fig.5

Diagram of knitting needle simulation mode result. (a) First-order mode; (b) Second-order mode; (c) Third-order mode"

Tab.2

Comparison of calculation results between simulation and numerical analysis"

组别
编号		 伸出长
度/mm		 数值分析
频率/Hz		 仿真计算
频率/Hz		 偏差/
Hz		 相对偏
差/%
1 27 508.1 517.4 9.3 1.8
2 28 472.5 480.6 8.1 1.7
3 29 440.5 450.9 10.4 2.3
4 30 411.6 421.1 9.5 2.3
5 31 385.5 392.2 6.7 1.7
6 32 361.7 367.0 5.3 1.4

Fig.6

Test platform for knitting needle vibration characteristics. (a) Knitting needle marking diagram; (b) Test platform physical map"

Fig.7

Shooting screen of high-speed camera. (a) Movement track of knitting needle; (b) Free attenuation oscillation process of knitting needle"

Fig.8

Vibration characteristics of knitting needles at high and low positions. (a) Time domain plot at high position; (b) Frequency domain plot at high position; (c) Frequency domain plot at low position"

Fig.9

Vibration characteristics of knitting needles moving along cam track surface. (a) Displacement curve; (b) Vibration time domain curve; (c) Vibration frequency domain curve"

[1] 黄肖华. 全自动扎口单面无缝内衣机控制系统[D]. 杭州:浙江理工大学, 2015: 6-20.
HUANG Xiaohua. Automatic control system of single side seamless underwear machine[D]. Hangzhou:Zhejiang Sci-Tech University, 2015: 6-20.
[2] 曹斌. 无缝针织内衣机成圈机构原理与工艺的研究与分析[D]. 杭州:浙江理工大学, 2011: 7-34.
CAO Bin. Research and analysis on the looping principle and technology of the seamless underwear knitting machine[D]. Hangzhou:Zhejiang Sci-Tech University, 2011: 7-34.
[3] 戴宁, 胡旭东, 彭来湖, 等. 无缝内衣机密度电动机的控制技术[J]. 纺织学报, 2020,41(6):161-167.
DAI Ning, HU Xudong, PENG Laihu, et al. Control technology for density motor used in seamless underwear machines[J]. Journal of Textile Research, 2020,41(6):161-167.
[4] 吴晓光, 孔令学, 朱里, 等. 磁悬浮式织针提花驱动方式理论研究与探讨[J]. 纺织学报, 2012,33(10):128-133.
WU Xiaoguang, KONG Lingxue, ZHU Li, et al. Theoretical research on propulsion mode of magnetic suspension needles for jacquard knitting[J]. Journal of Textile Research, 2012,33(10):128-133.
[5] 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.
[6] 向民奇, 毛汉领, 黄悦峰. 考虑安装面特性参数的悬臂梁固有频率分析[J]. 广西大学学报(自然科学版), 2019,44(6):1591-1599.
XIANG Minqi, MAO Hanling, HUANG Yuefeng. Natural frequency of cantilever beam considering the characteristics of installation surface[J]. Journal of Guangxi University(Natural Science Edition), 2019,44(6):1591-1599.
[7] 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):571-578.
LIU Yongchun, ZHAO Yanying. A modal testing method for cantilever beam[J]. Mechanics in Engineering, 2019,41(5):571-578.
[8] 王江萍, 常鹏飞. 基于VMD的振动模态固有频率识别[J]. 西安石油大学学报(自然科学版), 2018,33(3):92-106.
WANG Jiangping, CHANG Pengfei. Identification of natural frequency based on VMD[J]. Journal of Xi'an Shiyou Univer-sity(Natural Science Edition), 2018,33(3):92-106.
[9] 李涛, 白云峰, 朱世根. 基于机器视觉的织针自动化检测系统[J]. 毛纺科技, 2018,46(9):74-78.
LI Tao, BAI Yunfeng, ZHU Shigen. Automatic detection system for knitting needle based on machine vision technology[J]. Wool Textile Journal, 2018,46(9):74-78.
[10] 徐英莲, 齐素梅. SM8-TOP2无缝内衣圆机织针的运动参数分析[J]. 纺织学报, 2011,32(2):58-63.
XU Yinglian, QI Sumei. Analyzing needle track of SM8-TOP2 seamless-wear circular knitting machine[J]. Journal of Textile Research, 2011,32(2):58-63.
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