【作者】 李娟；

【导师】 包健；

【作者基本信息】 杭州电子科技大学 ， 计算系统结构， 2010， 硕士

【摘要】 钢丝轮胎因其舒适耐磨、高速缓冲、安全可靠等优点,成为近年来轮胎制造领域发展的主流。钢丝阵列作为轮胎的骨架材料,直接影响后期产品的支撑负荷和运行性能,逐渐成为生产中关键在线必检项目。虽然成品轮胎最终X射线检验能够发现大多数缺陷,但通过早期压延工序后检测钢丝是否按一定间距正确排列、切割拼接时是否有空隙或错位等,便可及时剔除次品,避免批量废品及后续加工的浪费,极大地降低了成本。因此,钢丝阵列的检测成为近几年学术领域及国际大公司的研究热点。传统的激光检测、X射线法因辐射伤害,开发成本高等因素被日渐取代,寻求安全、低成本、高灵敏度的新方法成为致力的目标,但迄今这方面研究的成功报道鲜少。本文基于电磁检测原理,提出一种钢丝阵列间隙及缺陷的检测方法,并利用有限元法对系统关键部件—传感器作了较为深入的研究。本文的工作主要包括以下几个方面:(1)提出钢丝阵列间隙的检测方法及传感器结构。根据检测系统物质状态变化及设备材料物理属性对电磁空间的影响而得到的信息辨识钢丝阵列间隙。所构造的传感器为高导磁、低功耗的软磁芯及缠绕的漆包线组成。理论分析表明了该方法用于工业检测的可行性。(2)建立检测系统的分析模型。首先根据电磁场的基本特性,以麦克斯韦方程为依托建立逼近实际工程问题的连续型数学模型,然后利用有限元法经等价离散化处理建立分析系统的三维模型。采用相应的数值计算法得出场域中任意点处的场强、损耗等电磁参数,使得此类复杂结构的电磁问题得到有效解决。(3)对检测系统进行性能优化。利用融合多场环境的有限元分析软件ANSYS进行系统的在线模拟检测,对传感器各项结构和物理参数进行优化,最大程度地提高传感器的灵敏度和系统的运行性能。(4)实现传感器微弱信号提取。传感器的输出信号较小,而外界及检测装置本身产生的随机噪声却很强,是一个微弱信号。本文利用锁相放大原理实现三维磁场传感器微弱信号处理,将深埋在大量非相关噪声中的微弱有用信号检测出来,同时达到抑制干扰作用。(5)分析钢丝阵列的各种典型缺陷。工业生产中钢丝阵列缺陷主要由缺根、错位、不规则、裂纹、断丝等,可以发生在钢带平面内,也可以发生在与磁芯轴线垂直与钢带平面正交的层面,或者二者的空间合成。本文详细分析缺陷状态下的各种信号,为系统的全面检测提供有效依据。本文提出的检测方法为电磁无损检测原理的应用进行了有益的探索与尝试,具有一定的理论价值和广泛的工业应用前景。更多还原

【Abstract】 In recent years, the rise of steel wire tire has become a trend in the development of tires manufacturing thanks to its excellent performance in terms of comfort, abrasion proof and high-speed buffer, safe and reliable, etc. As a skeletal material, the steel wire array has a direct impact on load supported and performance of the latter product and has become a compulsory on-line testing in production. The X-ray testing on the final tire can find most defects, however, at early stage, the defective products can be removed in time by the detection of arrangement of wire and cutting splicing after rolling process, which greatly avoid the wastes in large quantity and the large costs of the following processing. Therefore, recently, the research on the wire array detection becomes a hot spot of some international companies and academic institute. Traditional laser detection and X-ray method has been gradually replaced because of their shortcomings, says, harmful rays, large investment, so one of our targets is looking for a new method with safety of low-cost and high sensitivity. But the successful research is rarely reported so far. This dissertation presents a detection method of wire array gap and defects based on electromagnetic detection principle and do some in-depth research on the critical component of the system - sensors by finite element method.The main work of this dissertation can be listed as follows:(1) Present the steel wire gap detection method and sensor’s structure. According to the information from the electromagnetic space impacted by the material state change of detection system and physical properties of equipment materials. The sensor is comprised of soft-magnetic core with high permeability and low-power and the winding of the enameled wire. Theoretical analysis shows that the method for industrial inspection is feasible.(2) Establish the analysis model of detection system. First, according to the fundamental characteristics of electromagnetic field, we establish the continuous mathematical model of practical engineering problem based on Maxwell’s equations, and then establish the three-dimensional analysis model of system using the method of the equivalent discrete processing based on the finite element method. The electromagnetic parameters of any point in the domain of the field strength, depletion, etc. can be calculated by the corresponding numerical calculations methods, which can solve such a electromagnetic problem of the complex structure is resolved effectively.(3) Optimize the performance of the detection system. The finite element analysis software ANSYS which blends the multi-field environment was used to perform the on-line simulation, optimize the structure and physical parameters of the sensor, and to maximize the sensitivity of the sensor and system performance.(4) Extract the faint signal of detection system. The sensor output signal is weak while the random testing noise generated by outside world and the device itself is very strong. In this dissertation, the phase-locked amplifier circuit is used to detect the weak signal of the three-dimensional magnetic field buried in a large number of non-correlated noise and suppress interference effect at the same time.(5) Analyze various of typical defects in wire array. In industrial production, the shortcomings of steel wire array caused by the shortage of steel root, dislocation, irregular, crack, broken wires, etc., which can occur in the strip plane, and the core axis orthogonal to the vertical plane with the strip level, or the special synthesis of both. In this dissertation, we analyzed the signals in the defective state carefully to provide an effective basis for a comprehensive inspection of the system.The detection method proposed in this dissertation was a useful exploration and attempt for the application of electromagnetic non-destructive testing principles, which has some theoretical value and the prospects on a wide range of industrial applications.更多还原