Digital Integration for Lightweight-Optimized Cast Components.
CASTING, LOCAL MATERIAL BEHAVIOR, MATERIAL UTILIZATION
Assessing the lifetime of cast components depends increasingly on incorporating not just the load capacity of the material itself, but also within the scope of integration, information from the casting simulation as well as non-destructive component testing. This is generating more and more possibilities for assessing the situation of potential material defects in advance using casting simulation and transferring this to numerical simulation. This can help avoid defects and create lightweight geometries and optimize component lifetime.
The lifetimeassessment of the widest-ranging cast components often faces challenges in the evaluation of defects, if characteristic parameters of non-destructive component inspection exist but they are not available as digital data for the numerical simulation. New digital, non-destructive test methods, like those honed in the Lunkerfest, unverDROSSen and GrenzQualifizierung projects funded by the Federal Ministry for Economic Affairs and Energy, enable the determination of local characteristic values as well as their digital transfer to numerical simulation in order to digitally assess the influence of the defects on lifetime.
Harnessing the extensive knowledge of different disciplines
The aim of the aforementioned research projects, funded by the Federal Ministry for Economic Affairs and Energy, was and is to create a cast component which is optimized in terms of its lifetime and lightweight through a high degree of integration while incorporating the impact of local material defects at the same time. This should be done by integrating the disciplines involved in the component lifetime process such as structural durability, design, simulation and non-destructive testing (Figure 1). In the long term, the project aims to assess potential defects at the start of the design process by involving a solidification simulation with a numerical stress simulation and to make castability-related adjustments to the design directly. If local material strengths can also be taken into account depending on the simulated microstructural condition, this enables the quick definition of cast lightweight components in the optimal material.
Figure 1: Integration of disciplines for fast and reproducible product development as well as quality assurance. (© Fraunhofer LBF)
Figure 2: Design of the virtual limit sample for cast components.
(© Fraunhofer LBF)
Quality assurance also benefits from this approach to finding solutions. For instance, working with foundries, companies and research facilities with competencies for both the destructive and non-destructive component inspection and the simulation, a design for virtual limit samples is also set out in the “GrenzQualifizierung” project. With the aid of information from the solidification and stress simulation, the virtual limit sample depicts all conceivable potential material defects of the serial process, which are not yet critical for the component’s lifetime. Quality assurance additionally uses later on the virtual limit sample to facilitate a decision, both quickly and without recalculations, as to whether a component has to be rejected due to defects detected or can indeed be used (Figure 2). This is because the limit sample not only contains the local component properties, but also reflects critical stress thresholds based on defined operating loads in combination with possible defects.
A side effect of such an integration is that various critical component areas may be inspected quickly and using digital means to determine their behavior in relation to various load-time histories. If a cast component is critical for a particular use case due to defects detected, it can still be used in systems applied with lower loads. In this case, the component does not have to be rejected.
Funded by the Federal Ministry for Economic Affairs and Energy.
“The specialist dialog between all disciplines is essential for the optimization of cast components.” Dr.-Ing. Christoph Bleicher
The new InCeightCasting C8 congress invites all disciplines to join the discussion : www.inceightcasting.com
- Dr.-Ing. Christoph Bleicher
- Phone: +49 6151 705-8359