风电叶片脱层损伤的声振检测技术研究

发布时间：2018-03-21 07:05

本文选题：风机叶片　切入点：脱层　出处：《南京航空航天大学》2014年硕士论文　论文类型：学位论文

【摘要】：对风力发电设备进行无损检测是增加其寿命、降低维护成本的有效手段，在叶片的寿命期内及早的发现叶片存在的损伤，尤其是脱层损伤变得极为重要。本文首先论述了叶片在其寿命周期各个阶段出现脱层损伤的类型，并综述了国内外针对复合材料无损检测所使用的方法；然后对声振法进行了理论建模分析，确定了可以表征脱层缺陷信息的特征参数，并以此作为检测仪器设计的基础。论文论述了基于FPGA的风电叶片脱层损伤检测仪的工作原理。通过敲击锤激振叶片，对锤内力传感器所获取的信号进行特征分析，当叶片出现脱层时，，缺陷处刚度下降，敲击力持续时间增大。仪器的制作包括敲击锤的制作、硬件电路设计和软件设计三个部分。敲击锤的设计在考虑材料属性和质量要求后选择尼龙锤头，钢铁锤身的结构，并将压电薄膜传感器内嵌在锤头内。硬件电路的设计包括阻抗匹配、极性转换电路和滤波放大电路，将所得的信号分别输入数字信号处理模块和模拟信号处理模块。系统的核心器件为Altera的FPGA，对其软件部分的设计包括两个方面，一是数字逻辑模块，用来直接对力信号的持续时间进行检测，整个模块可直接作为后续SOPC系统的外设部件；二是SOPC系统的搭建，主要实现数据的采集、分析、显示和通信等功能。本文最后利用所研制的损伤检测仪对标准试件和实际损伤叶片进行了实验研究。实验数据显示，此仪器对薄层的脱层损伤具有良好的检测效果，并可依据检测结果的变化趋势规划脱层检测路径。
[Abstract]:Non-destructive testing (NDT) of wind power equipment is an effective means to increase its life and reduce maintenance cost. It is very important to find blade damage, especially delamination damage, as early as possible during the lifetime of the blade. In this paper, the types of delamination damage in each stage of the blade life cycle are discussed, and the methods used for nondestructive testing of composite materials at home and abroad are summarized, and then the acoustic vibration method is theoretically modeled and analyzed. The characteristic parameters which can represent the delamination defect information are determined and used as the basis for the design of the detection instrument. In this paper, the working principle of the wind turbine blade delamination damage detector based on FPGA is discussed. The characteristic analysis of the signal obtained from the hammer internal force sensor is carried out by tapping the hammer blade. When the blade is delaminated, the stiffness of the defect decreases. Percussion duration increases. The instrument consists of three parts: hammering, hardware circuit design and software design. The design of hammer is based on the structure of nylon hammer head and steel hammer body after considering material properties and quality requirements. The design of hardware circuit includes impedance matching, polarity conversion circuit and filter amplifier circuit. The core device of the system is the FPGA of Altera. The software design of the system includes two aspects: one is the digital logic module, the other is the digital logic module. It can be used to detect the duration of force signal directly, the whole module can be used as the peripheral component of SOPC system directly; secondly, the SOPC system is built, which mainly realizes the functions of data acquisition, analysis, display and communication. In the end of this paper, the standard specimen and the actual damage blade are studied by using the developed damage detector. The experimental data show that the instrument has a good effect on detecting the delamination damage of the thin layer. The delamination detection path can be planned according to the change trend of the detection results.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315;TG115.28

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