钢结构焊接接头质量检测与评估方法研究

钢结构焊接接头是钢结构中最常见的连接方式之一,其质量对于整个结构的安全性和稳定性至关重要。本研究旨在探索钢结构焊接接头质量检测与评估的方法,为提高钢结构焊接接头的质量提供有效的参考。本文首先介绍了钢结构焊接接头的概念及其在建筑和工程领域的应用。然后,详细阐述了现有的焊接接头质量检测方法,包括可视检查、无损检测和破坏性检测等。对于每种检测方法,分析了其原理、优缺点以及适用范围,以帮助读者选择合适的方法。接着,介绍了钢结构焊接接头质量评估的方法。主要包括基于经验统计的评估方法和基于数值模拟的评估方法。针对每一种方法,详细讨论了其原理、计算步骤和适用范围,并给出了实际案例进行说明。此外,本文还介绍了钢结构焊接接头质量检测与评估方法的发展趋势。

高硅铝合金激光封焊与焊接接头的工艺研究

针对高硅铝合金电子封装管壳激光封焊后,焊接接头附近易出现裂纹,产品密封成品率低的问题,提出了一种具有预热-焊接-后处理的激光脉冲波形。通过研究激光封焊工艺参数与管壳焊接结构的作用关系,以及焊接接头部位的微观结构,确定了符合可靠性要求的管壳焊接接头的结构,避免了裂纹等缺陷的发生,并通过了可靠性验证,将其应用到宇航用混合微电路生产中,产品合格率得到了极大的提升。

钛-钢复合板聚合釜设备的研制

通过对某石化项目聚合釜的主体材料TA1+Q370R复合板的焊接性分析,探讨钛-钢复合板焊接时存在的问题,设计出适宜的焊接接头结构,同时合理进行选材与参数确定,保障正确规范的焊接工艺参数。从而编制出钛-钢复合板焊接工艺规程及检测方法和合格指标,在聚合釜的制造中予以实施且检测合格,成功地完成了设备的制造,为今后此类设备的制造提供了施焊参数和检测方法。

Relationship between interfacial structure and property of steel-mushy Al-28Pb bonding pate

The interfacial properties of steel-mushy Al-28Pb bonding plate with different interfacial structures, and the influence of ratio of Fe-Al compound at the interface on interfacial shear strength were investigated. The results show that there is a nonlinear relationship between the ratio of Fe-Al compound at the interface and the interfacial shear strength. When the ratio of Fe-Al compound at the interface is smaller than 71.4%, with the increase of the ratio of Fe-Al compound at the interface, the interfacial shear strength increases gradually; when the ratio of Fe-Al compound at the interface is larger than 71.4%, with the increase of the ratio of Fe-Al compound at the interface, the interfacial shear strength decreases continuously; when the ratio of Fe-Al compound at the interface is 71.4%, the largest interfacial shear strength 70.2MPa is obtained.

Classification of Ultrasonic Signs Pre-processed by Fourier Transform through Artificial Neural Network Using the Echo Pulse Technique for the Identification of Defects in Welded Joints of Structural Steel

It is due to the need to ensure the security and integrity of equipment, that the non-destructive tests have been increasingly used in the industrial sector. Among these, the ultrasonic pulse echo technique is the most used in industry, mainly for its simplicity and efficiency. With one transducer only, it is possible to emit the ultrasonic and receive the echo pulse. The ANNs （artificial neural networks） are artificial intelligence techniques that, when properly trained, align themselves to inspection tests becoming a powerful tool in the detection and fault identification. In this work, the echo pulse technique was used to detect discontinuities in welds, where ANNs were fed from the information obtained by digital signal processing techniques （Fourier transform）, to identify and classify three distinct classes of defects. Results showed that with the combination of feature extraction by Fourier transformation and classification with neural networks, it is possible to obtain an automatic defect detection system in welded joints with average efficiency.