Ulbrich Dariusz, Kańczurzewska Marta
Faculty of Transport and Civil Engineering, Institute of Machines and Motor Vehicles, Poznan University of Technology, 60-965 Poznan, Poland.
Faculty of Control, Robotics and Electrical Engineering, Poznan University of Technology, 60-965 Poznan, Poland.
Materials (Basel). 2022 Feb 24;15(5):1701. doi: 10.3390/ma15051701.
Resistance spot welding as the basic method of joining car body elements has been used in the automotive industry for many years. For these connections, it is required to obtain the appropriate diameter of the weld nugget, which results in a high strength and durability of the connection during vehicle operation. The article presents the methodology of testing spot-welded joints using both destructive methods: shearing test of the spot weld and the ultrasonic method. The main goals of the performed tests are (1) to determine the correlation between the mechanical strength of a joint, measured in kN, and the selected parameters of the ultrasonic longitudinal wave with a frequency of 20 MHz propagating in the area of the spot weld and (2) to build and verify the predictive models of the weld nugget quality. The correlation of these parameters allows assessing the strength of the connection with the use of a non-destructive test method. On the basis of the performed analyses, it was determined that there is a strongly positive correlation between the number of reverse echoes and the force necessary to destroy the spot weld (0.41) and the diameter of the weld nugget (0.50). A strong negative correlation was also obtained between the number of echoes and the strength (-0.69) and diameter of the weld nugget (-0.72).
电阻点焊作为连接车身部件的基本方法，已在汽车工业中使用多年。对于这些连接，需要获得合适的焊核直径，这会使车辆运行期间连接具有高强度和耐久性。本文介绍了使用两种破坏性方法测试点焊接头的方法：点焊的剪切试验和超声方法。所进行测试的主要目标是：（1）确定以kN为单位测量的接头机械强度与在点焊区域传播的20MHz频率的超声纵波的选定参数之间的相关性；（2）建立并验证焊核质量的预测模型。这些参数的相关性允许使用无损检测方法评估连接强度。基于所进行的分析，确定反向回波数量与破坏点焊所需的力（0.41）和焊核直径（0.50）之间存在强正相关。在回波数量与强度（-0.69）和焊核直径（-0.72）之间也获得了强负相关。
