Structural life analysis method applied to hydraulic press welded frame construction

Total structural life analysis methodology, applicable to actual engineering structures, is presented in this paper. It is demonstrated on the case of special purpose hydraulic press, specifically its C-shaped welded frame. The frame is subjected to high loads due to the operation of integrated hydraulic cylinders. In order to withstand such demanding working conditions, welded frame is made of high-strength steel. Two different designs of load-bearing welded joints, partially and fully penetrated, are considered and their lifetime is compared. Series of analyses are performed to determine the total structural life. A numerical analysis of the welded frame structure is performed considering the elasto-plastic range of material behavior. Fatigue analysis is performed based on the results obtained by EP analysis, in order to determine initial crack location and life cycles to crack initiation. Crack growth analysis is performed in order to determine the critical crack dimensions and total structural life. This approach allows to predict the welded joints behavior and timely prevent structural failure. It can be concluded that fully penetrated welded joint exhibits a significant structural life advantage in comparison to partially penetrated joint.