Surface roughness influences on localization and damage during forming of DP1000 sheet steel

Sebastian Münstermann, Peerapon Wechsuwanmanee, Wenqi Liu, Junhe Lian
2019 Procedia Manufacturing  
Under the concept of "Industry 4.0", production processes will be pushed to be increasingly interconnected, information based on a real time basis and, necessarily, much more efficient. In this context, capacity optimization goes beyond the traditional aim of capacity maximization, contributing also for organization's profitability and value. Indeed, lean management and continuous improvement approaches suggest capacity optimization instead of maximization. The study of capacity optimization
more » ... costing models is an important research topic that deserves contributions from both the practical and theoretical perspectives. This paper presents and discusses a mathematical model for capacity management based on different costing models (ABC and TDABC). A generic model has been developed and it was used to analyze idle capacity and to design strategies towards the maximization of organization's value. The trade-off capacity maximization vs operational efficiency is highlighted and it is shown that capacity optimization might hide operational inefficiency. Abstract Surface roughness strongly influences the occurrence of edge cracks in metal forming processes. Recently, a submodelling approach has therefore been presented that is capable of predicting whether an edge forming process could be performed without failure events, but the macroscopic load-deformation behavior could not be predicted. This approach is extended to consider roughness induced micro damage even on the macroscopic scale. The concept is based on the idea to define an individual set of material parameters for those elements that are located at the sample´s surface. In order to calibrate the required set of parameters for these surface elements, sub-models are created which geometrically represent the roughness profiles that were determined experimentally before the bending tests were conducted. The procedure is demonstrated for the example of bending tests performed on samples made of steel DP1000 that have undergone two different surface treatments to adjust roughness conditions -fine grinding and polishing in the one extreme case and grinding with 80-grit sand paper in the other one. Experimental results reveal significant differences between the two sample configurations: while the samples with smooth surfaces remain free from cracks during the entire duration of the experiment, the samples with rough surfaces show fracture events. For both cases, the new simulation framework allows to reproduce both the macroscopic load-deflection curves and the individual damage and fracture behaviours. Abstract Surface roughness strongly influences the occurrence of edge cracks in metal forming processes. Recently, a submodelling approach has therefore been presented that is capable of predicting whether an edge forming process could be performed without failure events, but the macroscopic load-deformation behavior could not be predicted. This approach is extended to consider roughness induced micro damage even on the macroscopic scale. The concept is based on the idea to define an individual set of material parameters for those elements that are located at the sample´s surface. In order to calibrate the required set of parameters for these surface elements, sub-models are created which geometrically represent the roughness profiles that were determined experimentally before the bending tests were conducted. The procedure is demonstrated for the example of bending tests performed on samples made of steel DP1000 that have undergone two different surface treatments to adjust roughness conditions -fine grinding and polishing in the one extreme case and grinding with 80-grit sand paper in the other one. Experimental results reveal significant differences between the two sample configurations: while the samples with smooth surfaces remain free from cracks during the entire duration of the experiment, the samples with rough surfaces show fracture events. For both cases, the new simulation framework allows to reproduce both the macroscopic load-deflection curves and the individual damage and fracture behaviours.
doi:10.1016/j.promfg.2019.02.168 fatcat:petj4fyg6vazjmvooprtky6qqu