ISO 18592:2019

ISO 18592:2019 pdf free.Resistance welding – Destructive testing of welds – Method for the
fatigue testing of multi-spot-welded specimens.
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.
The specimens are designed to simulate, for joints in thin-walled structures, three basic types of loadings in their primary forms, i.e. shear load transverse to the joint line, shear load parallel to or in the axis of the joint line, and peel load (see Figure 1).
NOTE 1 For true-to-life thin-walled structures, it can generally be assumed that joints are never subjected to any of these types of stresses either singly or in a pure form. For lap joints, at least one type of shear stress and, due to the local deformation of the sheets caused by it, peel stress are present. Even if the primary stress in a lap joint is pure shear, a peel stress component is generated, whose absolute value depends on the magnitude of the deformation caused by the shear stress in the joint. This deformation is a function of the bending moment, which depends on the sheet thicknesses involved, the magnitudes of the forces acting and the local stiffness. The stiffness itself is a function of the sheet thicknesses, the Young modulus of the material(s), the flange width, the overlap, the location of the joint on the flange, the bending radii, etc. (References [8] to [11]).
NOTE 2 The specimens have been designed to permit the use of different joining technologies and, thus, allow a comparison of the load-carrying properties of joints made with different methods.
NOTE 3 For single- and double-hat specimens subjected to torsion and 3-point bending loads, the joints themselves are subjected to complex loads, whereby the ratios of the load types and the load distribution are non-uniform and undefined. Furthermore, the ratios of the three basic types of loads listed above are a function of the load amplitude, the clamping conditions, and the sheet material- and thickness combinations.
The quality, value and usefulness of the results of fatigue tests depend to a large extent on the degree of care taken in the fabrication of the specimens, their testing, the acquisition and evaluation of test data, and the comprehensiveness of the documentation.ISO 18592 pdf download.

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