Advanced Notch Strain Approach for Fatigue Calculation of Welded Components

The calculation methods for assessing the fatigue life of welded structures are gaining increasing importance in many technical applications, since they contribute in the decrease of the development costs and time. In various engineering applications, especially in the commercial vehicle sector with thick and thin components and welds of complex geometry and loading configurations, there is still a lack of experimentally verified guidelines for the calculation of fatigue life. The present paper shows an advanced procedure for FE modeling and fatigue life calculation of welds based on the Notch Strain Approach. It uses elastic-plastic cyclic material properties and can be applied in early stages of development when prototypes are not available. It can be applied to continuous and non-continuous welds, e.g. ones with pronounced terminations. Due to its local character, it covers both weld toe and root failures. To verify its accuracy, the proposed calculation procedure is applied to serial motor truck's rear axles providing complex 3D weld geometries subjected to cyclic loading. Calculated lifetime results are compared to experimental ones determined on a test rig. The agreement is satisfactory. (C) 2014 Elsevier Ltd.