Ralf Sturm

• aerospace engineering
• German Aerospace Center (DLR)

Due to the high computational burden and the high non-linearity of the responses, crashworthiness optimizations are notoriously hard-to-solve challenges. Among various approaches, methods like the Successive Response Surface Method (SRSM) have stood out for their efficiency in enhancing baseline designs within a few iterations. However, these metho...

Due to the high computational burden and the high nonlinearity of the responses, crashworthiness optimizations are notoriously hard-to-solve challenges. Among various approaches, methods like the Successive Response Surface Method (SRSM) have stood out for their efficiency in enhancing baseline designs within a few iterations. However, these method...

Transport systems are experiencing dramatic changes worldwide. The challenges to the development of environmentally sound solutions that are economically and technically feasible on the way to the mobility of the future require intensive efforts both in basic and application-oriented research. The global trends of urbanization, modularization, elec...

Developing sustainable products using high persistent and durable materials is challenging. Associated processes to mature innovations in industrial development are often inflexible due to safety reasons and economic requirements. A possible approach to solve these challenges can be found in digitalized development processes. By using optimization...

in the field of crashworthiness design, exploiting the full potential of weight reduction techniques while preserving the high safety standards of a vehicle still remains one of the major challenges. The computational cost of FEM simulations required to analyze the various crash load cases represents a real limitation to the optimization of vehicle...

in the field of crashworthiness design, exploiting the full potential of weight reduction techniques while preserving the high safety standards of a vehicle still remains one of the major challenges. The computational cost of FEM simulations required to analyze the various crash load cases represents a real limitation to the optimization of vehicle...

Studying complex phenomena in detail by performing real experiments is often an unfeasible task. Virtual experiments using simulations are usually used to support the development process. However, numerical simulations are limited by their computational cost. Metamodeling techniques are commonly used to mimic the behavior of unknown solver function...

Studying complex phenomena in detail by performing real experiments is often an unfeasible task. Virtual experiments using simulations are usually used to support the development process. However, numerical simulations are limited by their computational cost. Metamodeling techniques are commonly used to mimic the behavior of unknown solver function...

New optimization strategies are developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project. The computational costs required for the various crash load cases are challenging for optimization of vehicle structures are. Besides the simulation of the vehicle structures, the simulation of deformable crash barriers ar...

Exploiting the full potential of lightweight materials and weight reduction techniques while preserving the high safety standards of a vehicle still remains one of the major challenges in the field of crashworthiness design. Such a problem, already challenging from a qualitative point of view, is also hard to be solved numerically due to the comput...

New simplification strategies for crash simulations are developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project. The computational costs required for the various crash load cases are challenging for optimization of vehicle structures. In this paper an automated model generation for simplified vehicle crash mod...

Composite materials in automotive structures have the potential to reduce CO2 emissions by simultaneously saving weight and improving fatigue performance. Further weight reduction potential can be obtained by integrating additional functions into composite structures. Regarding a suspension system, the control arms and coil springs in a McPherson f...

In the world of vehicle structure optimization the goal is to find car components that are, for example, as light or cheap as possible while still being able to fulfill all legal bindings of crash safety. Therefore, bounded constrained optimization problems with one objective and several constraints must be solved. Like with most engineering optimi...

Highly automated vehicles (AVs) (the SAE levels 4 - 5 [1]) rely on perception sensor information, including LiDARs, radars, and cameras. One of the most important factors to consider when equipping these sensors on AVs is the safety integrity level these sensors can provide for operation. The required level of safety in the area of safety-critical...

Zur Erreichung der Pariser Klimaziele müssen Nutzfahrzeuge effizienter werden – Konventionelle müssen weniger Kraftstoff verbrauchen und Elektrische müssen mehr Ware weiter transportieren. Leichtbau, besonders mit Carbonfaser-verstärktem Kunststoff (CFK), ist dabei eine Schlüsseltechnologie. CarbonTT entwickelt CFK Chassis für 3,5t-Nutzfahrzeuge, d...

Elektrifizierte Fahrzeuge werden derzeit intensiv entwickelt und nehmen einen wachsenden Marktanteil ein. Mit diesen Fahrzeugen müssen auch neue Leichtbaukonzepte insbesondere für den Schutz der Batterie ent-wickelt werden. Diese können sich jedoch nur dann am Markt etablieren, wenn eine hochautomatisierte und flexible Herstellung sowie eine lastge...

Im Beitrag zur Auto[nom]Mobil im Rahmen der SafetyWeek 2020 geht es um die Forschungsthemen Fahrzeugkonzepte von autonomen Fahrzeugen und damit Verbunden Themen an Sicherheit mit Schwerpunkt Crash. Es wird das Fahrzeugkonzept des Next Generation Car Urban Modular Vehichle vorgestellt. Eine Fahrzeugfamilie von Fahrzeugen die selber gefahren werden b...

Seit mehreren Jahren erweitern die Fahrzeughersteller ihre Modellpalette mit einer Vielzahl verschiedenster Fahrzeuge. Die Spanne reicht von kleinen, leichten und sparsamen Fahrzeugen für den urbanen Bereich bis hin zu großen, komfortablen aber schweren und hochmotorisierten Fahrzeugen. Bedingt durch die geltenden Zulassungsnormen legen Fahrzeugher...

New optimization strategies for lighter and safer vehicle structures are developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project. Within this project innovative vehicle concepts are being investigated, which are used as technology platforms. A high grade of modularity is the main design specification of the Ur...

A challenge in the design and optimization of vehicle structures is the high computational costs required for crash analysis. In this paper an automated model generation for simplified vehicle crash models is presented. The considered crash load cases are the US NCAP (100%, 56 km/h), the Euro NCAP (40%, 64 km/h) and the IIHS Small Overlap (25%, 64...

Die Vielfalt an Fahrzeugmodellen nimmt bezüglich Geometrie und Masse seit einigen Jahren deutlich zu. Von kleinen, leichten Stadtfahrzeugen, bis hin zu großen SUVs mit einem Leergewicht von über 2 Tonnen, nehmen die unterschiedlichsten Fahrzeuge am Verkehr teil. Diese Vielfalt bringt jedoch Problemstellungen bezüglich der Fahrzeugkompatibilität bei...

Based on the requirements on the overall vehicle like driving dynamics, comfort, safety, ergonomics, costs, environmental safety and image the specific requirements on body-in-white components can be derivate. An important task of the material pre-selection is the mechanical properties and the structural requirements for each specific component. In...

New optimization strategies are developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project. Within this project novel vehicle concepts are being investigated as the Urban Modular Vehicle (UMV). A high grade of modularity is the main design specification of the UMV concept. This significantly influences the design...

A challenge in the design and optimisation of the vehicle front structures is the high computational costs required for crash analysis. A methodological approach to simplifying finite element vehicle models and crash barriers is presented in this paper. The methodology uses global deformation characteristics of structures which are obtained from th...

Three new vehicle concepts are being developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project: Urban Modular Vehicle (UMV), Safe Light Regional Vehicle and Interurban Vehicle. A high grade of modularity is the main design specification of the UMV concept. This significantly influences the design of the main str...

With the German Aerospace Center (DLR) Next Generation Car (NGC) Metaproject, the concepts and technologies, tools and methods for selected vehicles are developed in a networked research infrastructure. In the various disciplines of vehicle concepts, vehicle structure, drive train, energy and thermal management, vehicle intelligence and mechatronic...

A methodological approach to the development of an optimised side crash concept for the battery-electric vehicle concept Urban Modular Vehicle was presented in order to meet the requirements of a fully functional concept. In addition to the load path analyses shown, and the subsequent energy absorption process, validation tests at a coupon and comp...

This paper discusses manufacturing process, experimental testing and numerical simulation of braided Ω-frame segments bonded to a multiaxial fabric skin which represent the typical airframe structure. The Ω-frame preforms were manufactured using the circular braiding process and impregnated with resin by Vacuum Asissted Process (VAP) technique. The...

In the research project Next Generation Car (NGC) at the German Aerospace Center (DLR), three different novel vehicle concepts are being developed: Urban Modular Vehicle (UMV), Safe Light Regional Vehicle (SLRV) and Interurban Vehicle (IUV). The NGC project is the consolidation of tools, methods and technologies for the different vehicle concepts i...

Sandwich structures consisting of thin stiff facesheets and a thick, low density core exhibit excellent stiffness-to-weight ratio and are investigated for novel light weight fuselage concepts. Currently the application of sandwich structures in transport aircraft is limited to secondary structures, since further understanding is required in the fie...

Three new vehicle concepts in the field of transport are being developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project: Urban Modular Vehicle, Safe Light Regional Vehicle and Interurban Vehicle. In the submitted contribution, the focus lies on the development and application of a method for determining the veh...

Three new vehicle concepts in the field of transport are being developed at the German Aerospace Center (DLR) as part of the Next Generation Car META-project: Urban Modular Vehicle, Safe Light Regional Vehicle and Interurban Vehicle. In the submitted contribution, the focus lies on the development and application of a method for determining the veh...

In the presented thesis the damage initiation and failure of twin-walled fuselage panels is described under crash-relevant bending-compression-loads. Experiments under this loading condition showed that the failure of a twin-walled fuselage panel can be controlled by a local modification of the core through-thickness compression strength. As long a...

Over the last few decades, the fuel efficiency of aircrafts was mainly improved by the application of refined aerodynamics, new materials, structural optimization and enhanced engine performance. A further potential for a greener aircraft is seen in the unconventional blended-wing-body (BWB) design configuration due to its advanced aerodynamic desi...

Braided structures consisting of carbon/epoxy composite are regarded as one promising concept for producing low cost, high quality components with improved damage resistance. Whilst composite structures can exhibit excellent energy absorption capability under compression, brittle fracture modes limit their energy absorption capacity during bending...

Braided structures consisting of carbon/epoxy composite are regarded as one promising concept for producing low cost, high quality components with improved damage resistance. Whilst composite structures can exhibit excellent energy absorption capability under compression, brittle fracture modes limit their energy absorption capacity during bending...

The paper presents an homogenised core model suitable for use in the analysis of fuselage sandwich panels with folded composite cores under combined loading conditions. Within a multiscale numerical design process a failure criterion was derived for describing the macroscopic behaviour of folded cores under combined loading using a detailed foldcor...

The paper presents an homogenised core model suitable for use in the analysis of fuselage sandwich panels with folded composite cores under combined loading conditions. Within a multiscale numerical design process a failure criterion was derived for describing the macroscopic behaviour of folded cores under combined loading using a detailed foldcor...

For certification, novel fuselage concepts have to prove equivalent crashworthiness standards compared to the existing metal reference design. Due to the brittle failure behaviour of CFRP this requirement can only be fulfilled by a controlled progressive crash kinematics. Experiments showed that the failure of a twin-walled fuselage panel can be co...

New aircraft fuselage concepts have to prove equivalent crashworthiness standards compared to conventional metallic fuselages for certification. Brittle failure mechanisms of CFRP structures make the verification of equivalent crashworthiness for novel CFRP fuselage concepts challenging since conventional metal fuselages absorb a significant part o...

Zur Verbesserung der Crashsicherheit einer doppelschaligen Rumpfbauweise wurden am Institut für Bauweisen- und Konstruktionsforschung des Deutschen Zentrums für Luft- und Raumfahrt experimentelle Studien an Sandwichpaneelen unter Druck-Biegebelastung durchgeführt. In experimentellen Studien konnte nachgewiesen werden, dass bei einer doppelschaligen...

Die wissenschaftlichen und/oder technischen Arbeitsziele dieses Teilprojekts umfassen die Konzeptentwicklung und -bewertung einer Kabine in der Umgebung eines zukünftigen Ver-kehrsflugzeugs mit CFK-Rumpf. Hierbei sollen die Unterschiede, bzw. Vergleiche zu einer konventionellen Kabine in einer Metallrumpfumgebung herausgestellt werden. Anhand von n...