橡胶/铝合金粘接构件脱粘缺陷非线性超声检测技术研究

为提高橡胶/铝合金粘接构件粘接界面缺陷检测结果的可靠性,解决缺陷定量化表征问题,该文采用非线性超声检测技术对含模拟脱粘缺陷试样进行研究,建立非线性弹簧模型,通过采集模拟脱粘缺陷试样上缺陷处的基波信号和二次谐波信号,获得缺陷非线性系数β值,建立缺陷面积与非线性系数β值关系拟合曲线。对比自然试样中缺陷的非线性超声检测和超声C扫描检测结果,验证非线性超声检测结果可靠,因此非线性超声检测技术是评价橡胶/铝合金粘接构件粘接界面粘接质量的一种可靠方法。

新型陶瓷基复合材料粘接构件的脱粘超声检测信号处理方法

针对一种新型的陶瓷基多孔复合材料粘接结构件,利用超声C扫描系统对构件脱粘缺陷进行检测时,由于材料多孔性和各向异性导致超声数据产生强烈的声学噪声,造成重构图像边缘模糊。针对此问题,提出利用小波包时频域分析及能量谱分析的方法获取超声回波信号的频谱和能量谱特征。为增强回波信号的特征,采用自适应小波包阈值算法进行消噪处理,相较于传统的超声信号消噪方法信噪比提高了近20%,有效减小噪声信号对原始超声信号的干扰。在此基础上,对陶瓷基复合材料的粘接缺陷进行图像重建,对于直径为2 mm的微型脱粘缺陷也能够实现清晰表征。结果表明了所提超声信号处理方法的有效性,通过较大程度改善重构图像的质量,更清晰的反映了微小缺陷的边缘,从而提高了量化表征精度。

航空工业结构粘接质量控制

以金属结构粘接质量控制标准HB5 339— 1995为依据 ,重点介绍航空结构粘接质量控制的意义 ,以及对人员、设备、胶粘剂、文件资料、施工环境、粘接工艺。

建筑结构胶粘剂的应用及发展

建筑用胶粘剂已成为重要的化学建材,被广泛应用于施工、装修、密封和结构粘接等领域。

Adhesive bonding of composite aircraft structures:Challenges and recent developments

In this review paper,the challenges and some recent developments of adhesive bonding technology in composite aircraft structures are discussed.The durability of bonded joints is defined and presented for parameters that may influence bonding quality.Presented is also,a numerical design approach for composite joining profiles used to realize adhesive bonding.It is shown that environmental ageing and pre-bond contamination of bonding surfaces may degrade significantly fracture toughness of bonded joints.Moreover,it is obvious that additional research is needed in order to design joining profiles that will enable load transfer through shearing of the bondline.These findings,together with the limited capabilities of existing non-destructive testing techniques,can partially explain the confined use of adhesive bonding in primary composite aircraft structural parts.