Fraunhofer Ernst Machinery Institute

Ernst, Germany

Fraunhofer Ernst Machinery Institute

Ernst, Germany
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Siebold U.,Fraunhofer Ernst Machinery Institute | Hasenstein S.,Fraunhofer Ernst Machinery Institute | Finger J.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015

The article presents a case study of a web based application for urban security and safety enhancement. The application guides the user through a risk management process consistent with the international standard ISO 31000 and was originally developed in the EU project BESECURE for the management of improvement processes of urban quarters. The table-top assessment case study of the application to major football events is based on regulations and an existing and operational risk management documentation of a major German town. First, it is shown how external and internal contexts are defined, i.e. who stakeholders are and which objectives they peruse. Step by step, the risk management process is conducted for the iterative identification, evaluation and treatment of risks on the objectives in the context of football events. For each step, the main contents identified are discussed as well as the pros and cons of main features of the approach, including interactive and incremental completion, scalability to available analysis time and effort, compliance with a minimum and sufficient set of logic relations, e.g. relating stakeholders to objectives, etc., enabling the user to benefit from former case studies and the provision of a documentation and communication framework. Finally, the overall software-supported risk management process is critically evaluated with respect to efficiency and new insights obtained. In particular, it is shown that the tool support facilitates to conduct risk management as well as going systematically beyond minimum legal risk reduction requirements. © 2015 Taylor & Francis Group, London.

Schoppe C.,Fraunhofer Ernst Machinery Institute | Zehetner J.,Fraunhofer Ernst Machinery Institute | Finger J.,Fraunhofer Ernst Machinery Institute | Baumann D.,Fraunhofer Ernst Machinery Institute | And 2 more authors.
Safety and Reliability: Methodology and Applications - Proceedings of the European Safety and Reliability Conference, ESREL 2014 | Year: 2015

Risk management schemes have been applied to very diverse domains including logistics, health care, aviation, construction, defense, finance and security. Within common risk management processes the selection of dedicated risk assessment methods is crucial to fulfill the general requirements of such processes and some of the most critical risk management steps. There is a generic set of methods recommended by standards. These methods normally originate from a certain purpose but can be applied to systems and processes in general. The main goal of this article is to facilitate the selection of appropriate methods for risk assessment of issues occurring in the context of urban security and safety. Therefore we review and classify most of the risk assessment methods recommended by the generic standard ISO 31010 with respect to criteria relevant for their application in the urban security context, including estimated effort, needed data, expertise and technical support, specificity, and relevance. © 2015 Taylor & Francis Group.

Renger P.,Fraunhofer Ernst Machinery Institute | Siebold U.,Fraunhofer Ernst Machinery Institute | Kaufmann R.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
Safety and Reliability: Methodology and Applications - Proceedings of the European Safety and Reliability Conference, ESREL 2014 | Year: 2015

Airport check points are vital infrastructure for secure and safe air transport. They consist of an ever increasing number of components. Also the interactions between the checkpoint components as well as the checkpoint itself and external systems are expected to further increase in the future, e.g. if profiling and more risk based methods are applied. As a basis of analyzing airport checkpoints with respect to security and safety a sufficient system understanding is a prerequisite. The Systems Modeling Language (SysML) is used to accomplish that, which is a system engineering adaption of the Unified Modeling Language (UML). We show how static and dynamic properties of airport checkpoints are modeled using SysML. Aiming at an overall modeling of different airport checkpoint designs, we model a generic airport checkpoint design using SysML. The model comprises standard airports as in operation at many airports today. Throughout the paper, we give a broad outlook how these semi-formal models are applied to new ACP concepts as for example proposed by the famous "airport of the future" project as well as distributed checkpoints, where parts of the screening happens "on the fly" by stand-off screening equipment without intrusion for the passenger. © 2015 Taylor & Francis Group.

Kisters T.,Fraunhofer Ernst Machinery Institute | Kuder J.,Fraunhofer Ernst Machinery Institute | Nau S.,Fraunhofer Ernst Machinery Institute
Shock Waves | Year: 2015

This paper reports on a new gauge for blast impulse determination close to explosive charges. The gauge is based on the autonomous data recorder g-rec developed at the Ernst-Mach-Institute for data acquisition in harsh environments. Combined with an acceleration sensor these data recorders allow for the direct determination of the momentum transferred to an object by a blast wave even in the immediate vicinity of the explosive charge. From this the blast impulse can be determined. Using autonomous electronics distinct advantages are gained compared to classical passive momentum traps. The paper summarizes the properties of the g-rec recorder and describes the setup of the autonomous momentum trap in detail. Numerical simulations are presented which illustrate the gauge performance and its limitations. Tests with 1 kg charges demonstrate the feasibility of the approach. Good agreement was found between simulations and tests. The application range of the gauges is determined by the measurement range of the built-in acceleration sensor and its overall dimensions and weight. The present configuration is designed for distances between (Formula presented.)0.3 and 1 m from charges between several 100 g and several kilograms. Data were successfully collected down to reduced distances of 0.25 m/kg(Formula presented.). Minor changes in gauge dimensions, weight, or measurement range enable the gauges to be deployed at even closer distances. © 2015 Springer-Verlag Berlin Heidelberg

Ebenhoch S.,Fraunhofer Ernst Machinery Institute | Nau S.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
Journal of Defense Modeling and Simulation | Year: 2015

Exploding foil initiators (EFIs) are highly suitable for use in inline fuze trains containing only secondary high explosives, mainly due to their insensitivity with respect to electromagnetic disturbances or mechanical stress, their precisely controllable fire characteristics and compact size. During EFI operation various multi-physical phenomena occur, such as high-volt switching, foil explosion, generation and acceleration of the flyer plate, as well as shock wave initiation of the explosive by flyer plate impact. In this work all the physical processes, including their coupling, are modelled using multi-physical models that neither employ complex finite elements computations nor experimentally determined fitting parameters. Implemented in a simulation tool, the complete EFI behaviour is covered, from firing (switching) to explosive initiation. Complementary experiments with test structures are conducted, analysing the electrical behaviour and the resulting flyer velocities of different EFI designs. Comparison with these experiments demonstrates the consistency of the simulations and sufficient accuracy. The validated simulation tool is used to determine all-fire/no-fire criteria, to improve geometries and materials and to analyse parasitic influences in the firing circuit. The paper shows that this model-based approach can be used to assess high reliability and safety either for existing or when developing new EFIs. © 2014, 2014 The Society for Modeling and Simulation International.

Kaufman J.E.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
Advances in Safety, Reliability and Risk Management - Proceedings of the European Safety and Reliability Conference, ESREL 2011 | Year: 2012

Active protection systems protect vehicles against impact threat, e.g., from high-speed armor-piercing kinetic energy projectiles, shaped charges or improvised devices. Using an on-board computer system and sensors, approaching threats are detected, tracked, classified and then mitigated if found to be a critical threat. In particular, interception of close-in threats in an urban setting, the question arises which safety requirements have to be fulfilled to avoid unintended functioning, possibly resulting in casualties in the vicinity of the vehicle. This paper presents a general approach that applies to any hard-kill active protection system that has to react in a very short time without assuming specific technical system details. The overall functional safety requirements are determined by evaluating individual and collective risk criteria. We discuss alternative derivations of these requirements and their implicit assumptions. We show which requirements have to be fulfilled in typical scenarios. Ranges for critical risk values are also proposed. © 2012 Taylor & Francis Group.

Siebold U.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012, PSAM11 ESREL 2012 | Year: 2012

For safety relevant and critical systems a crucial part of the development is a concise and complete safety requirement definition. We show how requirements can be modeled with graphical, semiformal means using the systems modeling language SysML. However, aiming at an unambiguous and formal requirement definition and verification, we do not focus on diagrams that are typically used for requirement definitions, e.g. the SysML requirement, parametric and use case diagrams. We rather use the state machine diagram to define safe and unsafe states as well as sequences of states that are expected within the overall system and within subsystems. We show how generic types of safety requirements are represented using extended versions of state machine diagrams. To this end we model expressions that are similar in semantics to linear temporal logic expressions using the SysML state machine diagrams. In particular, we can distinguish, whether a strict sequence of states is required or some kind of intermediate states are allowed within the sequence, e.g. from an unintended initial unsafe state to a final safe state in case of an active safety function. Finally, we will indicate how this approach can be used in future to verify that overall state machine diagrams of systems or subsystems fulfill these formalized requirements.

Kaufmann R.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute
Safety, Reliability and Risk Analysis: Beyond the Horizon - Proceedings of the European Safety and Reliability Conference, ESREL 2013 | Year: 2014

Geo Information Technology (GIT) and Geo Information Systems (GIS) for visualizing qualitative and quantitative risk analyses are of interest in the areas of large-scale events from disaster scenarios like forest fires and river flooding, to urban scenarios concerning urban security assessment and planning of future cities and quarters as well as military settings like overflight scenarios of moving hazard sources. The paper gives an overview of the range of applications of such 2D, 2.5D GIS and 3D visualizations as well as software tools employed within quantitative risk analyses. The main aim of the paper is to find key criteria for the selection of a suitable visualization for computer-supported risk analyses. We consider different scenario sizes, e.g. from airports to large-scale over flight scenarios with rockets. We distinguish static and dynamic scenarios, e.g. hazard propagation or changes in person distribution. A further criterion for the assessment of the suitability of visualization techniques and tools for quantitative risk analyses is whether GIS and visualization data can be used for risk modeling within one software tool, or more generally, how good the data exchange between the visualization and the modeling can be organized. In summary, we propose for computer-supported quantitative risk analyses applications suitable 3D and GIS visualizations. As basis for the investigation we use a subset of existing, emerging and future risk analysis application tools that are currently developed and take also our software technical framework and development conditions into account. © 2014 Taylor & Francis Group, London.

Cunrath R.J.M.,Fraunhofer Ernst Machinery Institute | Wickert M.,Fraunhofer Ernst Machinery Institute
IEEE Transactions on Plasma Science | Year: 2016

Impact and shock wave events represent typical extreme dynamic loads of interest for accessing the response of materials and structures. Here, we focus on an intense electric current pulse as an extreme dynamic load. Experimentally, metallic samples were electromechanically loaded with currents up to 400 kA. For this purpose, a test rig containing a high-voltage pulsed power supply and high-performance switches was built. In this paper, we present an approach for modeling the response of thick metallic wire samples, with diameters on the order of millimeters, to extreme electromechanical loads sufficient for deformation and fragmentation, but not for material disintegration by wire explosion. The essential electrodynamic, thermodynamic, and mechanical aspects are considered, and a way to couple those physical regimes is suggested, which allows the use of numerical simulation based on the finite-element method to determine the material response. Simulations are employed to describe the time-dependent process of the structural and material behavior of thick wires. The focus here is on the structural mechanical behavior including bending or buckling before the onset of the wire explosion. The new approach for a simulation model is able to capture the basic experimental observations. © 2015 IEEE.

Schoppe C.A.,Fraunhofer Ernst Machinery Institute | Haring I.,Fraunhofer Ernst Machinery Institute | Siebold U.,Fraunhofer Ernst Machinery Institute
Safety, Reliability and Risk Analysis: Beyond the Horizon - Proceedings of the European Safety and Reliability Conference, ESREL 2013 | Year: 2014

The five-step risk management scheme of ISO 31000 or similar schemes have been applied to very diverse domains including logistics, health care, aviation, construction, defense, finance and security. We show that the risk management process of ISO 31000 can be modeled with the semi-formal Systems Modeling Language (SysML). We model requirements and process described in ISO 31000. We present how selected SysML diagrams are employed, namely the use case diagram, activity diagram and requirement diagram. We select a minimum set of well-known methods for fulfilling the requirements of the risk management process for hazard risks as well as for opportunity risks. We use examples mainly in the urban security domain for illustration of the risk/opportunity management process. In addition, we indicate how to use the risk management scheme for modeling the monitoring of the evolution of risks and chances as well as for modeling an early warning system, e.g. during the application of recommended counter actions and actions, respectively. © 2014 Taylor & Francis Group, London..

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