共查询到18条相似文献,搜索用时 296 毫秒
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蜂窝夹芯结构常见缺陷有蒙皮与蜂窝芯脱粘、蜂窝芯变形、蜂窝芯节点开裂和蜂窝积水等,目前单一的无损检测方法还不能有效地解决蜂窝夹芯结构中的各种缺陷检测问题。针对铝蜂窝夹芯结构,首先制作了6种典型人工缺陷,利用射线DR(Digital Radiography)和计算机射线照相(Computed Radiography,CR)技术对夹杂、蜂窝芯变形、蜂窝芯格断裂、富胶等缺陷进行了数字射线成像检测,得到了高质量的缺陷数字检测图像,并进行了对比分析。针对蜂窝积水检测问题,采用射线DR技术进行了数字成像检测研究,表明积水量大小会影响图像灰度。对含有人工脱粘缺陷的铝蜂窝夹芯结构件,采用脉冲反射法对其粘接质量进行了超声C扫描成像检测研究,通过底波幅值成像得到了脱粘缺陷的超声C扫描数字图像。结果表明:数字射线成像和超声C扫描成像结合为蜂窝夹芯结构提供了一种数字化的无损检测方法。 相似文献
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蜂窝结构钎焊接头的声阻法检测成像 总被引:1,自引:0,他引:1
利用声阻法对蜂窝结构钎焊接头质量进行了检测。按照相关标准制作了含人工缺陷的试件,根据声阻检测原理得到检测信号并确定了手动检测工艺。利用手写板提取探头位置信号,通过VC++.NET编写的检测程序与相应的检测信号结合生成声阻C扫描图像,并与超声C扫描检测结果进行对比。试验表明,声阻法工艺简单,检测速度快,可分辨蜂窝结构中约10mm的未焊合缺陷。声阻C扫描图像可显示缺陷位置及大小,且其精度达到检测要求。 相似文献
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针对扩散连接界面缺陷的无损检测问题,开展了人工缺陷试样的水浸超声检测试验研究,提出了扩散连接界面缺陷超声响应模型,开发了一种通过超声检测评估界面缺陷厚向尺寸的检测手段. 首先利用扩散连接的方法制备了带有人工缺陷扩散连接试样,采用30 MHz的入射波频率,对试样进行水浸超声无损检测. 基于超声无损检测原理提出了未焊合缺陷的超声响应模型,引入扩散连接界面劲度系数K作为桥梁建立起超声反射波反射率与界面缺陷尺寸之间的联系. 通过特定检测位置的超声反射波数据和实际微观缺陷尺寸数据拟合确定超声响应模型常数,进而实现基于超声无损检测的界面缺陷厚向尺寸评估. 结果表明,传统超声C扫描一般只是定性地反映缺陷存在与否,而厚向尺寸评估方法的提出在一定程度上为超声C扫描做了补充,有助于缺陷尺寸的定量检测,实现缺陷危害等级的评估. 相似文献
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针对蜂窝钎焊件、钎焊平板和钎焊雷达缝阵天线表层结构三种钎焊结构,设计制作了超声C扫描对比试样,试验了不同的人工缺陷的加工方法。通过对不同试样制作方法和人工缺陷加工方法的对比,确定了不同钎焊结构适用的对比试样制作方法。结果表明,制作平板钎焊结构对比试样时,应尽可能采用在平板状态钻出通孔后入炉焊接的方法。制作蜂窝钎焊结构对比试样时,采用焊后在蜂窝中注入固化剂固化,钻铣出平底孔后通过加热或化学方法去除将固化剂去除的方法效果较好。制作模拟天线表层钎焊结构对比试样时,采用焊后在下层板靠近筋条位置铣出条状缺陷的方法效果较好。 相似文献
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为了有效检测胶接结构缺陷,构建了基于声阻法的成像检测系统. 系统包括声学信号采集、声学探头定位、数据处理及绘图三部分. 利用两轮式编码器,实现了动态扫查过程探头位置信息的采集;利用结合质量检测仪采集缺陷信息;采用C + + 编写了数据处理及图像绘制程序,实现了胶接结构缺陷声阻法实时成像检测. 利用声阻法及常规超声C扫描成像方法对铝合金/环氧树脂/铝合金三明治胶接结构进行了检测,并对检测结果进行了分析对比. 结果表明,声阻法能更有效识别胶接结构中的缺陷,且单面检测即可满足缺陷表征需求. 相似文献
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Inspecting damaged structures repaired with composite patches is one of the most challenging issues of different industries, especially in aeronautical vehicles. Various inspection methods such as ultrasonic (UT) and thermographic methods are commonly applied to the patches and bondings. Although, both ultrasonic and thermographic inspections have their own capabilities, they are also associated with some limitations especially in the inspection of complicated structures such as multilayers. Different data fusion techniques can be used to overcome these limitations, by exploiting the advantages of each inspection technique to achieve the goal to have a more precise and reliable defects assessment. In this paper, different image fusion algorithms are used to fuse the UT C-scan and thermal images obtained from thermographic inspection of carbon/epoxy patches bonded to an aluminum plate. The inspected specimen contained several delaminations of various sizes and locations along with some disbond defects which were artificially embedded in five samples of composite patches. The resulting images of 28 fusion algorithms and the input images have been quantitatively compared using Average Differences (AD) to clarify the efficiency of the fusion algorithm. Comparing results revealed that contrast pyramid was selected as the best image fusion algorithms which can be used for NDE fusion of carbon/epoxy patches bonded to an aluminum plate. 相似文献
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The effect of notching on fiber-reinforced metal laminates (FML) is studied 3-2 lay up carbon fiber aluminum laminates specimens
containing a circular hole were employed in notch tests. The notch effect for a composite laminate was investigated and compared
with carbon/epoxy composites and aluminum sheets. The degradation of notch strength for carbon fiber aluminum laminates was
smaller than for carbon/epoxy composites. The point and average stress criteria were used in the notch strength analysis.
A finite width correction factor was also used. The strength degradation models involve a single parameter that is a function
of the hole size and the characteristic length. These models were compared with experimental data and good agreement was found. 相似文献
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Scott L. Poveromo James C. Earthman 《JOM Journal of the Minerals, Metals and Materials Society》2014,66(6):970-978
One of the leading challenges to designing lightweight, cost-effective bonded structures is to detect low shear strength “kiss” bonds where no other defects such as voids and cracks exist. To develop a nondestructive testing method that is sensitive to kiss bonds, standards need to be fabricated with known strength values. In the current work, we attempt to create kiss bonds in between carbon fiber composite laminates that have been bonded with epoxy film adhesive and epoxy paste adhesive. Based on ultrasonic testing, when creating true kiss bonds using film adhesives, a complete disbond could not be avoided because of thermally induced stresses during the high-temperature cure. However, further work demonstrated that kiss bonds can be formed using room-temperature curable epoxy paste adhesives by creating an amine blush on the epoxy surface or applying a release agent on the bonding surfaces. 相似文献
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铝蜂窝芯因具有特殊的薄壁网格状结构,传统加工方式往往伴随着变形和毛刺,这是限制铝蜂窝材料应用的关键因素。超声振动加工在减少加工缺陷方面具有很大的潜力。建立有限元模型并进行切削模拟,同时进行铝蜂窝芯切削实验,对铝蜂窝芯在不同振幅和不同主轴转速下切割的表面形貌进行探究,并对不同振幅下圆刀片的磨损程度进行对比。结果表明:与普通切削相比,纵扭复合超声振动切削能够获得更好的表面形貌,更有效地降低切削缺陷数目;随着振幅的增大,切削缺陷数目得到减少,刀具磨损程度得到降低,切削表面的均匀一致性也变得更好,但施加的超声振幅过高也会导致胞壁产生分离;主轴转速增大能够很好地改善胞壁变形和胞壁分离现象。同时,在1 350~2 700 r/min之内存在一个最佳转速,使得切削缺陷数目可以达到最少。 相似文献