塔机臂架结构损伤检测识别技术研究

发布时间：2018-03-14 00:16

本文选题：损伤检测　切入点：平头塔式起重机　出处：《哈尔滨工业大学》2012年硕士论文　论文类型：学位论文

【摘要】：近年来塔机在工程施工中得到了广泛的运用，然而伴随而来的是塔机事故的逐年增加，事故发生的原因有很多种，其中由于材料本身的缺陷或者焊接工艺不合理以及伴随塔机服役时间而出现的损伤，包括疲劳裂纹、腐蚀等原因引发的损伤事故占相当比例，因此针对塔机金属结构损伤的检测识别技术研究迫在眉睫。本文研究了基于应变指标的臂架结构损伤检测识别方法及其具体实施方式，进行了检测点的优化布置分析，，利用有限元数值模拟实例进行了验证。结合实际应用的具体工况，分析了该方法在实际应用中的局限性以及可能采取的弥补措施。运用小波信号奇异性分析理论，研究了移动载荷下梁结构损伤检测识别方法。利用有限元软件进行了移动载荷作用下含裂纹损伤的简支梁和悬臂梁的瞬态分析数值模拟，对梁位移及梁上某点位移时程信号进行小波多分辨率分析。通过小波系数在尺度－空间上的突变，识别出单个裂纹、多个裂纹在梁上的空间分布位置，并以Lipschitz指数进行损伤程度量化描述。利用有限元数值模拟模型，进一步分析了载荷移动速度对损伤识别效果的影响，结果表明移动载荷移动速度慢较快好。以STT753型平头式塔式起重机的臂架标准节为例，研究了移动载荷作用下臂架结构损伤的小波检测识别方法。利用有限元瞬态分析方法获得臂架及上某点的位移时程的动态响应信号，依据小波分析系数在尺度－空间上的突变性质识别裂纹损伤的位置。结合塔机臂架标准节的实际应用工况，进行了单损伤、多损伤下采样点位置及数目的优化布置分析。利用等比例缩尺的塔机臂架模型，进行了移动载荷下臂架损伤小波检测识别方法的实验验证。实验数据分析表明，当臂架模型存在单处损伤和两处损伤时，提取弦杆自由端在移动载荷作用下的加速度、位移时程响应信号，并对其进行小波多分辨率处理分析，能确定损伤位置。实验结果表明基于小波分析的损伤检测识别技术在工程实际中具有一定的应用前景。本文是对塔机臂架结构损伤检测识别技术的一次初步尝试，讨论了损伤位置和程度的有效检测识别问题，得出的一些结论、数据，为塔机及其他设备的结构损伤检测提供了一定的参考，具有一定的应用价值。
[Abstract]:In recent years, tower cranes have been widely used in engineering construction. However, with the increase of tower crane accidents year by year, there are many reasons for the accidents. Among them, due to the defects of the material itself or the unreasonable welding process and the damage caused by the service time of the tower crane, the damage accidents caused by fatigue cracks, corrosion and other reasons account for a considerable proportion. Therefore, it is urgent to study the detection and identification technology of tower crane metal structure damage. In this paper, the damage detection and identification method of boom structure based on strain index and its specific implementation method are studied, and the optimal arrangement of detection points is analyzed. The finite element numerical simulation example is used to verify this method. The limitation of this method in practical application and the possible remedial measures are analyzed. Using the wavelet signal singularity analysis theory, the damage detection and identification method of beam structure under moving load is studied. The transient analysis numerical simulation of simply supported beam and cantilever beam with crack damage under moving load is carried out by using finite element software. The wavelet multi-resolution analysis of the beam displacement and the time-history signal of a point displacement on the beam is carried out. By the mutation of the wavelet coefficients in the scale-space, the spatial distribution of the single crack and the multiple cracks on the beam is identified. Using the finite element numerical simulation model, the influence of load moving velocity on damage identification is further analyzed. The results show that the moving load moves slowly and better. Taking the standard jib joint of STT753 type flat head tower crane as an example, In this paper, the wavelet detection and identification method for the damage of boom structure under moving load is studied. The dynamic response signals of the displacement time history of the boom and the upper point are obtained by using the finite element transient analysis method. The location of crack damage is identified according to the abrupt character of wavelet analysis coefficient in scale space. Combined with the practical application condition of standard section of boom of tower crane, the optimum arrangement of sampling point location and number under single damage and multiple damage is analyzed. In this paper, the experimental verification of wavelet detection and identification method of boom damage under moving load is carried out by using the model of tower crane with equal scale. The experimental data analysis shows that when there are single damage and two damage in the boom model, The acceleration and displacement response signals of the free end of the chord under moving load are extracted and analyzed by wavelet multi-resolution processing. The experimental results show that the damage detection and identification technology based on wavelet analysis has a certain application prospect in engineering practice. This paper is a preliminary attempt to detect and identify the damage of boom structure of tower crane, discusses the problem of effective detection and identification of damage location and degree, and draws some conclusions and data. It provides a certain reference for structural damage detection of tower crane and other equipment, and has certain application value.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3;TH165.3

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