本文件规定了在室温和最大80%的相对湿度下，对厚度范围为0.5 mm至5 mm的多点焊和多轴试样进行恒定载荷幅值疲劳试验的试样和程序。该文件对较大厚度的适用性可能受到机械性能的限制，例如试样材料的屈服强度和可成形性。高级高强度钢(AHSS)的厚度范围通常低于3.0 mm。例如，更大的厚度适用于铝合金。 根据所使用的试样，可以根据结果评估以下材料的疲劳行为: -经受限定的均匀载荷分布的点焊； -经受限定的非均匀载荷分布的点焊； -经受不同定义的剪切组合的点焊-、剥离和法向拉伸载荷；和 -测试样本。 可以实现不同载荷分布的多点试样如下: a)定义的均匀载荷分布: H-剪切和剥离载荷试样（横向于接头线承受均匀剪切或剥离载荷的焊缝）； 经受四点弯曲的单帽和双帽试样（在焊缝排方向上承受均匀剪切载荷的点焊）； 扭转下的双盘试样（承受均匀剪切载荷的点焊）； 拉伸载荷下的双圆盘试样（承受均匀剥离载荷的点焊）； 扭转和拉伸组合载荷下的双圆盘试样； 使用定义的夹具的扁平多点样本； b)定义的非均匀载荷分布: H-具有改进握把的样本； 带标准夹具的改进H型试样； 具有改进夹具的改进H-试样； 带有改进夹具的扁平多点样品； 带标准夹具的改进多点扁平试样； 用改进的夹具改进的多点扁平试样； c)剪切、剥离和法向拉伸载荷的定义组合: KS-2标本； 双圆盘试样； d)经受未定义的非均匀载荷分布的点焊——在扭转、三点弯曲和/或内部压力下的单帽、双帽和类似的封闭空心截面。 上述c）项下提及的试样和试验在本文件中不再进一步讨论，因为用这些试样获得的结果是特定于被试验部件的，并且可能不被推广或用于导出与载荷相关的数据-焊缝的承载行为。通过这种测试获得的结果适合于将测试部件的机械性能与以相同方式测试的类似部件的机械性能进行比较。然而，这些测试不适合评估或比较焊缝的承载性能。 用构件样试样获得的疲劳试验结果适用于推导承受循环载荷的结构和构件的材料和厚度组合选择标准。这一说法特别适用于具有边界条件的试样获得的结果，即局部刚度与所讨论的结构相似。只有当使用中的载荷条件和接头区域的设计刚度相同时，疲劳试验的结果才适合直接应用于设计。注:修改样本以考虑设计提出的限制或特定要求，例如小于标准重叠、小于或大于标准熔核直径以及特定载荷分布，从而提高测试结果对设计工程师的价值。

This document specifies test specimens and procedures for performing constant load amplitude fatigue tests on multi-spot-welded and multi-axial specimens in the thickness range from 0,5 mm to 5 mm at room temperature and a relative humidity of maximum 80 %. The applicability of this document to larger thicknesses can be limited by mechanical properties such as yield strength and formability of the specimen material. The thickness range for advanced high strength steels (AHSS) is generally below 3,0 mm. Greater thicknesses apply for aluminium alloys, for example. Depending on the specimen used, it is possible from the results to evaluate the fatigue behaviour of: — spot welds subjected to defined uniform load distribution; — spot welds subjected to defined non-uniform load distribution; — spot welds subjected to different defined combinations of shear-, peel- and normal-tension loads; and — the tested specimen. Multi-spot specimens with which the different load distributions can be realized are the following: a) defined uniform load distribution:

1. H-specimens for shear- and peel-loading, (welds subjected to uniform shear or peel loading transverse to the joint line);
2. single- and double-hat specimens subjected to four-point bending (spot welds subjected to uniform shear load in the direction of the row of welds);
3. double-disc specimen under torsion (spot welds subjected to uniform shear load);
4. double-disc specimen under tensile load (spot welds subjected to uniform peel load);
5. double-disc specimen under combined torsion and tensile loading;
6. flat multi-spot specimens using defined grips;

b) defined non-uniform load distribution:

1. H-specimens with modified grips;
2. modified H-specimens with standard grips;
3. modified H-specimens with modified grips;
4. flat multi-spot specimens with modified grips;
5. modified multi-spot flat specimens with standard grips;
6. modified multi-spot flat specimens with modified grips;

c) defined combinations of shear-, peel- and normal-tension loads:

1. the KS-2 specimen;
2. the double disc specimen;

d) spot welds subjected to undefined non-uniform load distribution — single-hat, double-hat and similar closed hollow sections under torsion, 3-point bending and/or internal pressure. The specimens and tests referred to under c) above are not dealt with further in this document, because the results obtained with these specimens are specific to the components as tested and may not be generalized or used for deriving data pertaining to the load-carrying behaviour of the welds. Results obtained with such tests are suitable for comparing the mechanical properties of the tested components with those of similar components tested in the same manner. These tests are, however, not suitable for evaluating or comparing the load-carrying properties of the welds. The test results of the fatigue tests obtained with component like specimens are suitable for deriving criteria for the selection of materials and thickness combinations for structures and components subjected to cyclic loading. This statement is especially relevant for results obtained with specimens with boundary conditions, i.e. a local stiffness similar to that of the structure in question. The results of a fatigue test are suitable for direct application to design only when the loading conditions in service and the stiffness of the design in the joint area are identical. NOTE Specimens are modified to take into consideration constraints or specific demands posed by design, e.g. smaller than standard overlap, smaller or larger than standard nugget diameter, and specific load distribution, thus enhancing the value of the test results for the design engineer.