The torsion test is rarely used for resistance spot-welded joints since they are not subjected to torsion in applications. Normal, shear, and/or peel loads are usually the main stresses. Extensive scientific investigations in the context of Kunsmann’s dissertation date back more than 50 years. These investigations are still the basis of ISO 17653 and the German guideline DVS 2916-1. Recent scientific investigations only use torsion tests, but do not describe the reason for its use. A decisive advantage of the torsion test over the other standardized destructive testing methods lies in the types of fracture modes that occur and the properties of the fracture surfaces. Torsional loading results in either interfacial or button-pulled fracture modes. No material residues occur on the fracture surfaces for ductile and advanced high-strength steels. Hence, the measurement of weld diameter is achievable with minimal constraints, resulting in reduced variability and facilitating objective assessments of spot welds. This article delineates these attributes through a comparative analysis of various destructive testing methods employing statistical approaches. Additionally, the article expounds on the design concept of the developed rig for conducting torsion tests on spot welds.

扭转测试很少用于电阻点焊接头，因为它们在应用中不会受到扭转。法向载荷、剪切载荷和/或剥离载荷通常是主要应力。昆斯曼论文背景下的广泛科学研究可以追溯到 50 多年前。这些调查仍然是 ISO 17653 和德国指南 DVS 2916-1 的基础。最近的科学研究仅使用扭转测试，但没有描述其使用的原因。与其他标准化破坏性测试方法相比，扭转测试的决定性优势在于发生的断裂模式类型和断裂表面的特性。扭转载荷导致界面断裂或纽扣拉断模式。对于延性钢和先进高强度钢，断口上不会出现材料残留。因此，焊缝直径的测量可以在最小的限制下实现，从而减少可变性并促进点焊的客观评估。本文通过使用统计方法对各种破坏性测试方法进行比较分析来描述这些属性。此外，本文还阐述了所开发的点焊扭转试验装置的设计理念。