WEB Experimental and numerical preliminary investigations of the base material and preformed components regarding fatigue crack growth in joined structuresTuesday (22.09.2020) 14:30 - 14:45 Z: Special Symposia II Part of:
In many areas of product manufacturing constructions consist of individual components and sheets that are joined together to form complex structures. A simple and industrial common method for joining different types and coated materials is Clinching. During the joining process and due to the service load cracks can occur in the area of the joint, propagate due to cyclic loading and consequently lead to structural failure. For the prevention of these damage cases fracture mechanical material parameters and knowledge about the fatigue crack growth behavior in clinched structures are essential. Taking into account the mutability of the process chains numerical as well as experimental investigations regarding the fracture mechanical behavior as well as the influence of local properties of preformed joining parts have to be carried out. Therefore, the scope of the presentation is about preliminary fracture mechanical investigations of the base material and preformed components.
In order to determine the fracture mechanical parameters (e.g. Threshold value ΔKI,th, fracture toughness KIC) of the 1.5 mm thick base material, the development of a new specimen geometry is necessary due to the low sheet thickness. Following the experimental validation of numerical determined functions (geometry factor function and calibration function), crack propagation curves are determined for the stress ratio R = 0.1. Furthermore, the different rolling directions (along and across) and further R-ratios (R = 0.3 and R = 0.5) are also considered in the experimental investigations to examine the influence of the anisotropy arising during rolling and the mean stress sensitivity.