After post weld treatment with high frequency mechanical impact (HFMI) treatment of welds, a significant increase of fatigue life (up to a factor of 10) can be achieved. During the last years numerous experimental tests of welded joints with simple geometry under constant amplitude loading have been performed to quantify the positive effect of high frequency mechanical impact treatment. Due to the lack of methods for the prediction of the high frequency mechanical impact benefits, a widespread use of this process is not the case yet. Furthermore, it is still not clear if the results of these fatigue tests can be transferred to complex geometries and complex loading conditions such as in industrial applications. Therefore, an approach to assess the fatigue life of complex welded structures under variable amplitude loading was developed. For this purpose, high frequency mechanical impact treatment and fatigue load of simple welded specimen made of S690QL steel were simulated with finite element analysis (FEA) firstly. Then, the needed damage parameters for the fatigue life correlation were evaluated from the finite element postprocessing. The calculated life time to crack initiation was in good agreement with the experimental fatigue test results. In the next step, this procedure was implemented on a welded arm of an evacuator of type EW180B of the company Volvo Construction Equipment made of S700MC. The variable amplitude load measured under real service condition was transferred to single constant amplitude load cycles using a rainflow-counting algorithm. By simulation and damage mechanics evaluation of each load cycle the total damage sum could be calculated and compared with the experimental results from Volvo Construction Equipment.Keywords: Fatigue / welding / residual stresses / high frequency mechanical impact (HFMI) / finite element analysis (FEA) Nach einer Schweißnahtnachbehandlung mittels Hochfrequenzhämmern (engl. high frequency mechanical impact treatment (HFMI)) kann eine signifikante Lebensdauerverlängerung des Bauteils (bis zu einem 10-fachen) festgestellt werden. Während der letzten Jahre wurde dieser positive Effekt vielfach experimentell mit einfachen Proben-

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This study is concerned with a design process for a foldable container structure using a finite element analysis. A foldable container structure consists of frames, panels and hinge systems. The main structure of a foldable container carries all the loads while a hinge system is designed to provide its foldability. In this work, finite element structural analyses for the main foldable container structure are carried out based on the ISO standard regulation, whose results are then taken for the design of a hinge system. The finite element analysis with two types of hinge systems are also performed. It is found out that the main structure of a standard 20ft container could be used for the foldable container with the same capacity if the corner edge in the side assembly is strengthened. It is also concluded that the hinge systems proposed in this work could be successfully used in a foldable 20ft container.