PSI - Issue 73

3

Jakub Flodr et al. / Procedia Structural Integrity 73 (2025) 9–13 Jakub Flodr , Petr Lehner, Dominik Gřešica, Martin Krejsa / Structural Integrity Procedia 00 (2025) 000–000

11

point of the neck. The manual assessment is based on the shape of the neck in both cases. From the point of view of rotational symmetry, the analyzed cross-section to be judged can be defined as the area of the intermediate ring formed in the section of the neck and the rotation about the axis of symmetry of the clinch joint (see Fig. 1 and Fig. 2). The shear and tensile stresses are then applied to this intermediate ring for verification. In the case of the calculation of a clinch connection subjected to shear stress, the equivalent area of the intermediate ring is determined from the average of the two measured values. This equivalent area is selected based on the failures observed under shear loading and verified by a numerical model. A cross-section of the clinch joint with the equivalent area highlighted can be found in Fig. 1, where the width of the clinch is indicated by t 1 and t 2 , these values are then averaged to produce the equivalent area of the intermediate ring cross-section. For the manual design of the clinch connection for tensile loading, the situation is simpler. Under tensile loading, there is a net failure at the weakest point of the clinch. Determination of the equivalent cross-section is not necessary. In Fig. 2, a section at the location of the clinch can be found.

Fig. 2. Graphical representation of an equivalent cross-section for manual design of a clinch joint under tensile load.

2.2. Calculation procedure The manual assessment can then be divided into assessments for shear stress combined with bending and for tensile stress. For the elasticity verification in the selected section, the plasticity condition must be satisfied (see equations (1, 2, 3, 4)): � , / � 2 + � , / � 2 −� , / � ∙ � , / � +3 � / � 2 ≤ 1 (1) = , (2) , = (3) , = (4)