Analysis of damage-dependent performance in deep-drawn metal components

The presence of damage in the form of voids and lattice defects in sheet metal components is a critical factor that significantly affects their mechanical performance, especially in high stress scenarios such as fatigue loading or crash events. These voids and lattice defects disrupt the structural integrity of the material by introducing weak points that can act as stress concentrators, increasing the likelihood of crack initiation and propagation. Effective control of damage during the forming process is therefore of paramount importance. By closely monitoring and controlling the accumulation and distribution of voids and lattice defects, the microstructural properties of the metal can be influenced, resulting in improved strength, durability and overall performance of the final component. This paper focuses on the damage accumulation in sheet metal during deep drawing and its impact on the component performance. For this purpose, U-profiles made of dual phase steel DP800 were deep drawn with different process parameters. The components were then analyzed considering the induced damage in areas critical to performance by means of scanning electron microscopy. Void area fractions and the ratio of damage mechanisms to void area fraction were determined. Afterwards, the components were cut into notched tensile tests, subjected to tensile tests and the performance in terms of stress-strain-curves was analyzed.