Fraunhofer-Publica

The Fraunhofer-Publica has been successfully documenting the research results of the Fraunhofer-Gesellschaft for over 30 years. The platform enables the collaborative linking of research-relevant objects and disseminates within the international scientific community.

The Fraunhofer-Publica thus fulfils its responsibility to promote the transfer of knowledge and know-how to industry and society.

Research outputs

As an application-oriented research organisation, Fraunhofer aims to conduct highly innovative and solution-oriented research - for the benefit of society and to strengthen the German and European economy.

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Projects

Fraunhofer is tackling the current challenges facing industry head on. By pooling their expertise and involving industrial partners at an early stage, the Fraunhofer Institutes involved in the projects aim to turn original scientific ideas into marketable products as quickly as possible.

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Researchers

Scientific achievement and practical relevance are not opposites - at Fraunhofer they are mutually dependent. Thanks to the close organisational links between Fraunhofer Institutes and universities, science at Fraunhofer is conducted at an internationally first-class level.

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Institutes

The Fraunhofer-Gesellschaft is the leading organisation for applied research in Europe. Institutes and research facilities work under its umbrella at various locations throughout Germany.

Recent Additions

Cylindrical steel tanks subjected to long-duration and high-pressure triangular blast load: Current practice and a numerical case study

( 2024)
Rosin, Julia
;
Stocchi, Alessandro
;
Bruckhaus, Norman
;
Heyner, Johanna
;
Weidner, Philipp
;
Waas, Till

This paper presents an investigation into the design of ammonia tanks for long-duration and high-pressure blast loads. The focus is on cylindrical steel tanks that apply as outer pressure-tight containers for double-walled tanks storing refrigerated liquefied gases. Based on limited empirical data, it is known in the tank industry that these tanks can withstand an explosion pressure up to a peak overpressure of approximately 10 kPa and 100 ms positive load duration. However, there is a growing need to design tanks for higher peak overpressures in order to establish a higher safety standard and accommodate unforeseen future requirements. This paper explores the concept of adapting established steel tank designs to handle high-pressure and long-duration overpressure due to blast events. Numerical analysis is conducted on a representative steel tank geometry subjected to a triangular blast load of 30 kPa with a 300 ms positive load duration. Various load application and calculation options are analyzed numerically. Considering the challenging nature of analyzing tank structures under blast load, the paper addresses controversial aspects discussed in the literature and presents a suitable analysis concept for a deflagration blast scenario for cylindrical tanks. The results provide insights into the expected structural behavior of the tank under high-pressure and long-duration overpressure. The main finding is that the calculation method developed in this study demonstrates the feasibility of utilizing steel tanks in scenarios involving long-duration and high-pressure blast loads. Furthermore, the paper provides recommendations to guide future studies in this area. The findings have implications for the design and construction of tanks in critical infrastructure and offer valuable insights for engineers and researchers in this field, improving safety standards and ensuring adaptability to future utilization concepts.
Tensile load-bearing behaviour of concrete components reinforced with flax fibre textiles

( 2024)
Ricker, Marcus
;
Kuhn, Sebastian
;
Feiri, Tânia
;
Zecherle, Katrin
;
Binde, Jan
;
Winkelmann, Jana

In recent years, the use of natural flax fibres as a reinforcement in composite building structures has witnessed a growing interest amongst research communities due to their green, economical, and capable mechanical properties. Most of the previous investigations on the load-bearing behaviour of concrete components reinforced with natural flax fibres include inorganic impregnations (or even no impregnation) and exclude the use of textile fabrics. Also, the mechanical behaviour of textiles made of natural flax fibres produced as leno fabrics remains to be investigated. In this paper, the results of tensile tests on concrete components reinforced with bio-based impregnated leno fabrics are presented. For comparison, multilayer non-impregnated and impregnated textiles were considered. The results demonstrated that reinforced textiles yielded an increase in the failure loads compared to the concrete cross-sections without reinforcement. The stress-strain diagrams showed that the curves can be divided into three sections, which are typical for reinforced tensile test specimens. For the impregnated textiles, a narrowly distributed crack pattern was observed. The results showed that impregnated textiles tend to support higher failure stresses with less strains than non-impregnated textiles. Moreover, an increase in the reinforcement ratio alongside larger opening widths of the warp yarns enables higher failure loads.
Monolithically Integrated GaN Power Stage for More Sustainable 48 V DC-DC Converters

( 2024)
Basler, Michael
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Mönch, Stefan
;
Reiner, Richard
;
Benkhelifa, Fouad
;
Quay, Rüdiger

In this article, a fully monolithically integrated GaN power stage with a half-bridge, driver, level shifter, dead time and voltage mode control for 48 V DC-DC converters is proposed and analyzed. The design of the GaN IC is presented in detail, and measurements of the single function blocks and the DC-DC converter up to 48 V are shown. Finally, considerations are given on a life cycle assessment with regard to the GaN power integration. This GaN power IC or stage demonstrates a higher level of integration, resulting in a reduced bill of materials and therefore lower climate impact.
Flexible PLA Copolymers with Low Melt Flow Index for Blown Film Applications

( 2024-04-01)
Rodriguez Hernandez, Benjamin
;
Lieske, Antje

A series of strategies are investigated, which allow internally plasticized polylactide (PLA)-polyether block copolymers to be effectively melt-processed through blown film extrusion in the semi-technical scale. Among the strategies presented are the use of tris(nonylphenyl) phosphite (TNPP) as a chain extender during the ring opening polymerization (ROP) of lactide and the application of ε-caprolactone (CL) as a plasticizing comonomer. The produced films have a significantly higher flexibility than pure PLA films and are in a comparable range to the flexibility of fossil-based, film-grade low-density polyethylene (LDPE) films.

Most viewed

Laser pulse energy conversion on sequence-specifically bound metal nanoparticles and its application for DNA manipulation

( 2005)
Garwe, F.
;
Czaki, A.
;
Maubach, G.
;
Steinbrück, A.
;
Weise, A.
;
König, K.
International Solid-State Circuits Conference 1994
Measurement of Local Recombination Activity in High Diffusion Length Semiconductors

( 2023)
Heinz, Friedemann
;
Oezkent, Maximilian
;
Rittmann, Clara
;
Schindler, Florian
;
Schubert, Martin
;
Kwapil, Wolfram
;
Glunz, Stefan

We present a conceptual approach for the localisation and characterisation of local sites of recombination in high diffusion length semiconductors under photovoltaic field conditions. While established imaging techniques operate in this very regime of uniform "1 sun" illumination, inevitable lateral diffusion of charge carriers veils the origin and severity of localised recombination sites. To reduce this limitation due to lateral diffusion the natural choice is using focussed charge carrier excitation and detection in combination with scanning the specimen. The resulting photoluminescence intensity maps are of high spatial resolution and may be composed of a superposition of a multitude of recombination active defects influencing each other due to the high bulk diffusion length. We demonstrate the feasibility of a self-consistent calibration of the setup quantum efficiency in such experimental condition which delivers a charge carrier density map in absolute units. A solution is presented to disentangle the superposition of local sites of recombination to isolate the actual recombination activity of every site. We demonstrate the feasibility of the approach experimentally on the high diffusion length semiconductor silicon.
27th International Symposium on Ballistics 2013. Proceedings. Vol.1: Interior Ballistics, Exterior Ballistics, Launch Dynamics, Vulnerability & Survivability, Explosion Mechanics

(DEStech Publications, 2013)