TY - CONF A1 - Seeber, Henrik T1 - Low level blast exposition – Hintergründe und aktuelle Entwicklungen N2 - Darstellung der Low Level Blast Thematik mit kurzer Einleitung, den internationalen Aktivitäten (hier SP) und einer Darstellung unseres Messsystems StEk. T2 - 25. Tagung Schutz gegen IED und ballistische Bedrohungen CY - Meppen, Germany DA - 09.04.2024 KW - Low Level Blast KW - Blast injury KW - Primäre Explosionswirkung KW - Druckwelle PY - 2024 AN - OPUS4-59868 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Experimenteller Ansatz zur Untersuchung der primären Explosionswirkung N2 - Schwerpunkt die Darstellung des Versuchsaufbaus zur Erzeugung von Verdichtungsstößen zur Simulation der Primären Explosionswirkung auf Simulanzien T2 - Angewandte Forschung für Verteidigung und Sicherheit in Deutschland CY - Bonn, Germany DA - 19.03.2024 KW - Stoßwellengenerator KW - Blast injury KW - Primäre Explosionswirkung KW - Druckwelle KW - Versuchsaufbau PY - 2024 AN - OPUS4-59869 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Experimenteller Ansatz zur Untersuchung der primären Explosionswirkung N2 - Explosionsverletzungen gehören zu den häufigsten Verletzungen bei militärischen Einsätzen. Während die Auswirkungen von Splittern, die als sekundäre Explosionsverletzungen eingestuft werden, durch die modernen ballistischen Körperschutzsysteme der Polizei und des Militärs minimiert werden konnten, stellen die Auswirkungen der Stoßwellenausbreitung im Körper als Teil des primären Explosionstraumas nach wie vor eine ernsthafte Bedrohung dar. Zusätzlich zu einzelnen einsatzbedingten Lastfällen liegt ein wissenschaftlicher Fokus auf besonders exponiertem Personal, z.B. aus den Einsatzbereichen „Taktische Zugangstechnik“, „Präzisionsschützenwesen“ oder Steilfeuerwaffen (Mörser). Repetitive mild traumatic brain injury (mTBI) können gesundheitliche Langzeitschädigungen wie und chronic traumatic encephalopathy (CTE) erzeugen. Um einen Beitrag zur Erforschung der primären Explosionswirkungen zu leisten, hat die Bundeswehr in Zusammenarbeit mit dem Bundeswehrkrankenhaus Berlin und der Bundesanstalt für Materialforschung und -prüfung (BAM) ein interdisziplinäres wehrmedizinisches Sonderforschungsvorhaben eingerichtet. Ziel der geplanten Untersuchung ist die Entwicklung einer multidisziplinären Methode zur Analyse des Stoßwellenverhaltens in verschiedenen generischen Gewebesimulanzien, sowie Schutzmaterialien unter möglichst realitätsnahen und reproduzierbaren Bedingungen. Für die Erzeugung reproduzierbarer Stoßwellen wurde ein Autoklav (Druckbehälter) entwickelt, mit dem durch die detonative Umsetzung eines Acetylen-Sauerstoff-Gemisches gut reproduzierbare Druckwellen unter Freifeldbedingungen erzeugt werden können. Vorteile dieser Methode sind unter anderem die kurzen Rüstzeiten zwischen Versuchsdurchgängen, die Minimierung störender Einflüsse im Vergleich zu Stoßwellenrohren und die geringeren Sicherheitsanforderungen im Vergleich zur Anwendung von konventionellen Sprengstoffen. Das generische Torso-Modell besteht in seiner einfachsten Form aus einem mit Druck- und Beschleunigungssensoren instrumentierten Gelatineblock, welcher eine Simulanz für organisches Gewebe darstellt. Zur Untersuchung des Stoßwellenverhaltens wurden verschiedene Medien, wie Hohlkörper, Festkörper und Gewebesimulanzien differenter Dichte in das generische Torso-Modell eingebracht. Einen besonderer Untersuchungsschwerpunkt bildeten die Grenzbereiche zwischen den unterschiedlichen Medien. Des Weiteren wurde analysiert, wie sich verschiedene Schutzmaterialien auf das Stoßwellenverhalten auswirken und mit welchen veränderten Eigenschaften die Stoßwelle anschließend in die Gewebesimulanz einkoppelt. T2 - Angewandte Forschung für Verteidigung und Sicherheit in Deutschland CY - Bonn, Germany DA - 19.03.2024 KW - Primäre Explosionswirkug KW - Blast injury KW - Pressure wave KW - Druckwelle PY - 2024 AN - OPUS4-59474 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Experimental Setup for the Reproducible Generation of Pressure Waves in Free Field Conditions N2 - The injuries caused by the primary blast are still poorly understood, especially in the torso region. To generate sufficiently large data sets, shock tubes are often used. However, these have some limitations, such as blockage, use of the exit jet, widening cross-sections, and scaling problems with respect to compressive strength and test objects. Therefore, it is appropriate to conduct experiments under free-field conditions, but tests with real explosives are often associated with long preparation and setup times as well as high safety requirements. Therefore, this paper presents an experimental setup for the reproducible generation of blast waves under free-field conditions. This experimental setup aims to provide a test environment for a sufficiently large specimen to investigate the behaviour of the shock wave within the specimen, especially at the media interfaces. As an example of application, the influence of the primary explosive effect on protective equipment or on tissue simulants for the investigation of blast injuries can be mentioned. An autoclave is used as a shock wave generator. It has a volume of 0.065 m3 and is filled with a stoichiometric acetylene-oxygen gas mixture. The setup and turnaround time is approximately 30 minutes. The following factors have been selected as target variables for the optimization of the shock wave generator: reproducibility of the pressure wave, use-case-relevant positive phase duration and peak overpressure, a pressure curve characteristic corresponding to that of a military explosive under undisturbed free field conditions, and short setup times of the experimental setup. For this purpose, the experimental setup is presented in this paper. Several series of measurements are presented, showing the characteristics of the generated pressure wave. For the generated pressure wave, the classical pressure curve characteristics can be clearly recognized. A peak pressure of 92 kPa is reached at a distance of 1 m from the opening, and the first positive pressure phase lasts 1.17 ms. Furthermore, the pressure wave propagates in a hemispherical shape. The typical characteristics of the blast wave generated by the SWG have been demonstrated using the military explosive PETN. It is shown that the actual load case corresponds to about 70 g of PETN. T2 - 26th International Symposium on Military Aspects of Blast and Shock CY - Wollongong, Australia DA - 03.12.2023 KW - Shock wave generator KW - Blast injury KW - Pressure wave KW - Experimental setup PY - 2023 AN - OPUS4-59356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik ED - Krentel, Daniel ED - Grasse, Dennis ED - Gerbeit, Marco ED - Grobert, Steffen ED - Hauer, Thorsten T1 - Experimental Setup for the Reproducible Generation of Pressure Waves in Free Field Conditions N2 - The injuries caused by the primary blast are still poorly understood, especially in the torso region. To generate sufficiently large data sets, shock tubes are often used. However, these have some limitations, such as blockage, use of the exit jet, widening cross-sections, and scaling problems with respect to compressive strength and test objects. Therefore, it is appropriate to conduct experiments under free-field conditions, but tests with real explosives are often associated with long preparation and setup times as well as high safety requirements. Therefore, this paper presents an experimental setup for the reproducible generation of blast waves under free-field conditions. This experimental setup aims to provide a test environment for a sufficiently large specimen to investigate the behaviour of the shock wave within the specimen, especially at the media interfaces. As an example of application, the influence of the primary explosive effect on protective equipment or on tissue simulants for the investigation of blast injuries can be mentioned. An autoclave is used as a shock wave generator. It has a volume of 0.065 m3 and is filled with a stoichiometric acetylene-oxygen gas mixture. The setup and turnaround time is approximately 30 minutes. The following factors have been selected as target variables for the optimization of the shock wave generator: reproducibility of the pressure wave, use-case-relevant positive phase duration and peak overpressure, a pressure curve characteristic corresponding to that of a military explosive under undisturbed free field conditions, and short setup times of the experimental setup. For this purpose, the experimental setup is presented in this paper. Several series of measurements are presented, showing the characteristics of the generated pressure wave. For the generated pressure wave, the classical pressure curve characteristics can be clearly recognized. A peak pressure of 92 kPa is reached at a distance of 1 m from the opening, and the first positive pressure phase lasts 1.17 ms. Furthermore, the pressure wave propagates in a hemispherical shape. The typical characteristics of the blast wave generated by the SWG have been demonstrated using the military explosive PETN. It is shown that the actual load case corresponds to about 70 g of PETN. T2 - 26th International Symposium on Military Aspects of Blast and Shock CY - Wolongong, Australia DA - 03.12.2023 KW - Shock wave generator KW - Blast injury KW - Pressure wave KW - Experimental setup PY - 2023 SP - 1 EP - 13 AN - OPUS4-59357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Influence of Torso Protective Equipment on Intracorporeal Shock Wave Behavior N2 - In the field of explosive reactions, there is a type of explosive effect that lacks a sufficient database and reproducible experiments regarding biomechanics. It concerns the primary explosive effect. It is defined as pure shock wave of the explosion. The physical behavior of the shock wave when interacting with different types of tissue and, in particular, the subsequent transitions of the shock wave, have barely been investigated. The transition of the shock wave into other materials is the focus of the research Therefore, the aim of the investigations is the development of a multidisciplinary method to investigate shock wave behavior in various generic tissue simulants under the most reproducible conditions possible with realistic loads in an experimental test series with short set-up times. An autoclave is used to generate the pressure waves. A simplified torso model consisting of ballistic gelatin is used as a simulant. In this paper, the influence of protective equipment on the pressure load in the tissue simulant is investigated. For this purpose, consecutive test setups are used. First, the behavior of ballistic gelatin as a tissue simulant is investigated. Then, the simplified torso model is covered with typical combat clothing consisting of four layers. Afterwards a currently used UHMWPE ballistic protective plate is placed in front of the simplified torso model. Finally, the combat clothing and the protective plate are examined in combination. Three cast-in pressure sensors are used as measuring devices, as well as an acceleration sensor attached to the protective plate. The experiments show that the maximum overpressure in a model protected by combat clothing and the protective plate can be reduced by 95%. However, the propagation speed of the shock wave within the simplified torso model increases from 1535.5 m/s to 2204.5 m/s. This shows that even protective equipment, which is not primarily intended to protect against blast, offers a significant reduction in the pressure load in the protected area. On the one hand it is caused by the media transition from air to PE and the resulting higher reflection of the acceleration of the transmitted wave within the simulant. On the other hand, it is also reduced due to the damping and dispersion caused by the clothing layers. T2 - 16th International Personal Armour Systems Symposium CY - Dresden, Germany DA - 11.09.2023 KW - Shock wave generator KW - Blast injury KW - Pressure wave KW - Experimental setup PY - 2023 AN - OPUS4-58639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik A1 - Grobert, Steffen A1 - Krentel, Daniel A1 - Hauer, Thorsten T1 - Influence of torso protective equipment on intracorporeal shock wave behavior N2 - In the field of explosive reactions, there is a type of explosive effect that lacks a sufficient database and reproducible experiments regarding biomechanics. It concerns the primary explosive effect. It is defined as pure shock wave of the explosion. The physical behavior of the shock wave when interacting with different types of tissue and, in particular, the subsequent transitions of the shock wave, have barely been investigated. The transition of the shock wave into other materials is the focus of the research Therefore, the aim of the investigations is the development of a multidisciplinary method to investigate shock wave behavior in various generic tissue simulants under the most reproducible conditions possible with realistic loads in an experimental test series with short set-up times. An autoclave is used to generate the pressure waves. A simplified torso model consisting of ballistic gelatin is used as a simulant. In this paper, the influence of protective equipment on the pressure load in the tissue simulant is investigated. For this purpose, consecutive test setups are used. First, the behavior of ballistic gelatin as a tissue simulant is investigated. Then, the simplified torso model is covered with typical combat clothing consisting of four layers. Afterwards a currently used UHMWPE ballistic protective plate is placed in front of the simplified torso model. Finally, the combat clothing and the protective plate are examined in combination. Three cast-in pressure sensors are used as measuring devices, as well as an acceleration sensor attached to the protective plate. The experiments show that the maximum overpressure in a model rotected by combat clothing and the protective plate can be reduced by 95%. However, the propagation speed of the shock wave within the simplified torso model increases from 1535.5 m/s to 2204.5 m/s. This shows that even protective equipment, which is not primarily intended to protect against blast, offers a significant reduction in the pressure load in the protected area. On the one hand it is caused by the media transition from air to PE and the resulting higher reflection of the acceleration of the transmitted wave within the simulant. On the other hand, it is also reduced due to the damping and dispersion caused by the clothing layers. T2 - 16th International Personal Armour Systems Symposium CY - Dresden, Germany DA - 11.09.2023 KW - Shock wave generator KW - Blast injury KW - Pressure wave KW - Experimental setup PY - 2023 SN - 978-9-0829-2732-0 SP - 178 EP - 187 CY - Brüssel AN - OPUS4-58640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Explosivstoffkunde - Physikalische Grundlagen und Explosionswirkung N2 - Der Vortrag „Explosivstoffkunde - Physikalische Grundlagen und Explosionswirkung“ ist ein Lehrvortrag, welcher die folgenden Unterkapitel enthält: Einteilung und Definition, Sprengstoffe und Kenngrößen, Physikalische Grundlagen, Explosionswirkung und Low Level Blast Belastung. Die thematische Tiefe stellt lediglich einen Überblick dar. Der Schwerpunkt liegt insgesamt auf der Auswirkungsbetrachtung von Explosivstoffen insbesondere auf der primären Explosionswirkung, also dem Überdruck oder auch Blast genannt. T2 - 25. Neurotraumakurs BwK Ulm CY - Ulm, Germany DA - 15.10.2024 KW - Primäre Explosionswirkug KW - Blast injury KW - Pressure wave KW - Druckwelle PY - 2024 AN - OPUS4-61446 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Investigation of intracorporeal shock wave propagation using a simplified torso model and a shock wave generator –a progress report N2 - Following directly from the information presented at IFBIC 2023 on the research project 'Investigation of intracorporeal shock wave propagation using a simplified torso model and a shock wave generator', the latest results are presented below [1]. In order to contribute to the research efforts on the primary explosion effects, the aim of the investigation is the development of a multidisciplinary method to investigate shock wave behavior in various generic tissue simulants under the most reproducible conditions possible with realistic loads in an experimental series with short set-up times. To achieve this, an autoclave with a volume of 0.065 m3 is used to generate reproducible pressure waves (Fig. 1). The autoclave will be referred to as Shockwave Generator (SWG). The pressure wave is produced by the detonation of a stoichiometric mixture of acetylene and oxygen under atmospheric conditions. The SWG-outlet is sealed by a rupture disc, which can be adjusted in thickness to vary the initial pressure. Additionally, modifying the composition of the acetylene-oxygen mixture can result in different load cases. The SWG requires approximately 30 minutes of set-up time between trials. The SWG was adjusted to match the characteristics of a real and typical explosive through free-field measurements. The experiments demonstrated that the pressure wave propagates in a hemispherical shape and has sufficient reproducibility. To represent soft tissue, a basic model made of homogeneous ballistic gelatin is used in a geometrically simplified torso model (STM) (Fig. 2). The STM was enlarged to outer dimensions of 400 x 250 x 240 mm. Viscoelastic behavior of the ballistic gelatin can be assumed due to the collagen structure [2]. The density of the ballistic gelatin, and therefore the sound velocity, can be adjusted by changing the mixing ratio. Simplified simulants, such as hollow and solid material (bone simulant), were embedded in the STM. Additionally, the STM has been tested as a carrier material for biological substances, such as indicator species. The next step is to test the STM as a carrier material for larger organic tissue structures such as lungs or kidneys. The organic tissue samples will undergo histological examination to analyze their structural changes afterwards. The STM is equipped with embedded piezoelectric pressure sensors, an accelerometer and a temperature sensor. Visual documentation is captured using a high-speed camera. This measurement setup allows for the tracking of the coupled pressure wave and its behavior within the model and at the media transitions. Pressure values can be recorded after certain media changes, such as from soft tissue to a solid material (Figure 3). The following is a review of the optimizations made to the entire experimental setup. The reproducibility of the SWG was increased. This was achieved by extending the evacuation process to the entire feed system of the SWG. Nitrogen residues in the SWG system can thus be avoided. As a result, the double peaks that occur at the first maximum can be avoided, as combustion runs more evenly without the nitrogen residues. In addition, partially varying peak overpressures can be avoided, as the acytelene-oxygen mixture is not too lean due to the elimination of the nitrogen residues. The workflow has been streamlined, resulting in an average set-up time of 25 minutes for the SWG. In the case of the STM, the manufacturing process in particular was optimized by examining and defining the manufacturing process based on scientific publications, which increases the reproducibility of the STM base bodies. As already mentioned in the previous paragraph, the STM was equipped with various additives in order to investigate the transition behavior of the pressure wave. The following trail serves as an example: A comparison is made between the STM in the basic structure (Fig. 2 l.s.) and with an embedded solid material (bone plate) (Fig. 3 l.s.). An external overpressure of 100 kPa is generated by the SWG at a distance of 1 m, where the STM is placed. For the basic STM structure, the sensor distance is consistently 100 mm. The internal overpressure is visible in Fig. 2 r.s.. A typical ideal pressure curve can be seen. The characteristic points are easily distinguishable from the reflection peaks. In the STM with an embedded solid material, the sensor distance remains consistently at 66.6 mm T2 - 8th International Forum on Blast Injury Countermeasures CY - Washington D.C., USA DA - 01.05.2024 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Experimental setup PY - 2024 AN - OPUS4-60044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Grobert, Steffen A1 - Seeber, Henrik A1 - Krentel, Daniel A1 - Hauer, Thorsten T1 - Entwicklung eines Körpermodells und eines Stoßwellengenerators zur Simulation der intrakorporalen Stoßwellenausbreitung nach Explosionen N2 - Im Rahmen des wehrmedizinischen Sonderforschungsvorhabens 29K4 wird der Effekt der primären Explosionswirkung auf Soldaten untersucht. Dazu wird ein Stoßwellengenerator entwickelt, der relevante Überdrucklastfälle mit geringer Rüstzeit und hoher Reproduzierbarkeit erzeugt. Zudem wird ein vereinfachtes Torso-Modell erstellt, um das Verhalten des eingeleiteten Druckstoßes in das Körpermodell zu untersuchen. KW - Ballistik KW - Blast KW - Explosion KW - Explosionstrauma KW - Verdichtungsstoß PY - 2024 VL - 2023 SP - 126 EP - 127 CY - Bonn AN - OPUS4-62382 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krentel, Daniel A1 - Seeber, Henrik T1 - Sensorträger Einsatzkraft – System zur Erfassung der kurzzeitdynamischen Belastung von Einsatzkräften N2 - Einsatzkräfte von Feuerwehr, Polizei, THW, etc., aber auch Passanten, sind im Training und auch der realen Gefahrenlage einer Vielzahl von Belastungen ausgesetzt. Neben u.a. Gefahrstoffen, elektromagnetischer Strahlung gibt es besondere Gefährdungen wie z. B. Explosionen, die durch eine kurzzeitdynamische Einwirkung charakterisiert sind. Dabei stellt die Überdruckbelastung eine unzureichend erfasste Gefährdung dar [1]. Zur Beurteilung dieser Gefährdung und potenzieller Schutzmöglichkeiten, ist die Erfassung und Charakterisierung der auftretenden Lastfälle in realistischen Einsatz- und Trainingsszenarien mit hochauflösender Messtechnik nötig [2, 3]. Bei der Erfassung sollen der Trainings- oder Einsatzablauf und die körperliche Belastung so gering wie möglich beeinflusst werden. Dies kann mit aktuell verfügbaren Messsystemen nicht gewährleistet werden. Die BAM stellt daher ein System, den „Sensorträger Einsatzkraft“ (StEk), als Prototyp vor. Dieser Prototyp besteht aus einem autarken, kurzzeitdynamischen Messsystem zur Erfassung der Überdruckbelastung von exponierten Personen. Das in einem Rucksack untergebrachte Messsystem zeichnet sich durch geringes Gewicht und Autarkie aus und ermöglicht damit erstmals den dynamischen Einsatz hochauflösender Messtechnik in Trainings- oder Einsatzszenarien mit wissenschaftlichem Anspruch. In Situationen, in denen der Einsatz eines Menschen nicht möglich ist, kann der StEk auch mit einem teilweise biofidelen Dummy mit ergänzender, verbauter Sensorik, eingesetzt werden. Darüber hinaus können mit diesem Ansatz kommerziell erhältliche Druckmonitoring-Tools auf ihre Eignung evaluiert und validiert werden. Derzeit wird ein weiteres autarkes Messsystem aufgebaut, das hinsichtlich der Leistungsfähigkeit der verbauten Messtechnik eine Weiterentwicklung des Prototyps darstellt. Neben der Erfassung kurzzeitiger dynamischer Belastungen sollen auch Belastungen des Trägers wie Lärm, körpernahe Temperatur und Wärmestrahlung erfasst werden können. T2 - Fachkongress „Forschung für den Bevölkerungsschutz“ CY - Bonn, Germany DA - 05.02.2025 KW - Blast KW - Low-level blast KW - Explosionswirkung KW - Einsatzkraft KW - Messtechnik PY - 2025 AN - OPUS4-62550 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gerbeit, Marco A1 - Seeber, Henrik A1 - Grasse, Dennis A1 - Donner, Marcel A1 - Grobert, Steffen A1 - Krentel, Daniel T1 - Test set-up for reproducible shock wave generation N2 - A test setup was developed at the BAM test site to generate and record reproducible, adjustable shock waves resulting from gas detonations. The setup is used to study the impact of blasts on humans and structures with short setup times. To further develop this innovative test bench and improve reproducibility, the ignition source and gas composition is analysed in more detail. The experimental setup consists of a cylindrical pressure vessel (autoclave) that is operated with acetylene and oxygen at ambient pressure. The elevated pressure resulting from the combustion process is released through an orifice by the instantaneous rupture of a diaphragm. The shock propagates symmetrically into the free field, where it interacts with the models and sensors to be analysed. With this design, shock waves with a typical ideal Friedlander waveform characteristic, except for a reflection and a muzzle blast-like behavior that deviates from the ideal characteristics, can be generated. This setup enables an average peak overpressure of 88 kPa. By using exploding wires as an ignition source in comparison to a fusehead, the reproducibility was significantly increased during the test to σ=2.8 kPa from σ=9.5 kPa previously. The presented data confirms the quality and reliability of this setup in generating realistic, reproducible shocks. KW - Overpressure KW - Shock wave KW - Blast KW - Ignition source KW - Autoclave PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637859 DO - https://doi.org/10.1016/j.jlp.2025.105736 SN - 0950-4230 VL - 98 SP - 1 EP - 6 PB - Elsevier Ltd. AN - OPUS4-63785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Investigation of Shock Wave Propagation in Soft Tissue Simulants: An Analysis of Organic Gelatin and Synthetic Gel N2 - This study investigates the effects of shock waves on soft tissue simulants, focusing on organic gelatin and a synthetic gel. Although extensive research has focused on the mechanical properties of soft tissue simulants, their behavior under shock wave conditions, such as those caused by blasts, is less understood. As explosives are increasingly used in modern combat scenarios, it is essential to study how shock waves interact with soft tissue. This knowledge is crucial for improving protective equipment and evaluating blast effects on the human body. A two-phase methodology was applied: First, organic gelatin production and synthetic gel composition were analyzed, identifying uncertainties and measuring sound speeds at varying temperatures to align with human tissue properties. Second, simulants were subjected to free-field shock waves, and embedded pressure sensors captured wave propagation, peak overpressures, and propagation velocity. Findings provide comparative insights into shock wave responses of simulants, offering a foundation for future experimental setups. KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Druckwelle PY - 2025 SN - 9781605956978 VL - 34 SP - 63 EP - 79 PB - DEStech Publications Inc. CY - USA AN - OPUS4-63320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik A1 - Grobert, Steffen A1 - Krentel, Daniel T1 - Description of a measurement setup for the combined measurement of LLB exposures in dynamic situations using high-resolution measurement technology N2 - In order to gain an understanding of the Low Level Blast (LLB) exposure of soldiers when using weapon systems, it is necessary to characterize these weapon systems with regard to their overpressure effect [1]. Carrying out static measurements of weapon systems in the rough terrain of firing ranges and training areas poses a challenge for sensitive measurement technology. Furthermore, soldiers are often exposed to LLB in dynamic situations [2]. Therefore, commercially available blast gauges are often used, which, however, are not sufficient for high-resolution measurement of overpressure exposures with academic requirements due to their intended use [3]. Static measurement setups, such as with penile probes, must be used to characterize weapon systems, but they cannot make valid statements about the real load on dynamically behaving soldiers. However, this real load on the soldier is essential in order to be able to adequately assess the potential resulting medical effects. As part of this challenging measurement task, a prototype of a self-sufficient, high-resolution measurement system is presented, which can be used by an operator in dynamic situations without interference. The complete measuring chain was realized as a self-sufficient unit. The system is based on a 20-liter backpack system, which contains the power supply, the measuring amplifier and the measuring card. The measuring computer is attached to the front of the backpack to allow quick access. The measuring system is capable of recording four channels with a sampling rate of up to 2 MHz. Piezoelectric integrated charge pressure sensors are used as a high-resolution pressure sensor (type: PCB138B32). The pressure sensor is placed on a XX- carrier plates with the dimensions XY × YY. The pressure sensors are attached at the typical positions for Blast-Gauges measurements, like on the left shoulder, on the upper chest and on the back of the head. At the same time, commercial blast gauges are placed at the positions of the pressure sensors to qualify the blast gauges (type: B3 Blast Gauges Gen 6). The measuring system is referred to as a “Sensor Carrier Operator (StEk)”. As part of the functional testing of the measurement system, tests are carried out with hand weapons. For this purpose, a soldier is equipped with the StEk and blast gauges. The handguns used are the pistole P8 (caliber 9 mm) and the long rifle G36 (caliber 5.56 mm). The firing position is standing freehand. In addition, the soldier carried out an examination of the carrying comfort of the StEk as part of the training. Furthermore, it was evaluated whether the measuring chain was adequately integrated into the measuring system. The quality of the pressure measurement was also examined, whereby a direct comparison was made with the blast gauges. The measurement system presented here enables the combined (static and dynamic) scientific characterization of weapon systems, particularly with regard to overpressure loading. T2 - Research Specialist Meeting HFM 371 (NATO STO) CY - Toronto, Canada DA - 09.04.2025 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Low Level Blast PY - 2025 SP - 1 EP - 8 AN - OPUS4-63322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Use of the shockwave generator for research on low-level blast effects - Monitoring vs. measurement tools N2 - In order to contribute to the research efforts on primary explosion effects, an experimental setup was created to generate realistic overpressure load cases under the most reproducible conditions and with short setup times. One focus of the project is now the applicability of this test setup for Low Level Blast (LLB) testing [1-3]. The basis of our experimental setup is the Shockwave Generator (SWG), which has already been presented in detail [4]. In addition, a stand-alone measurement system has been developed that can be worn by the operators who are exposed to LLB. The measuring system is referred to as the ´Sensor Carrier for Operator´ (StEk; German abbr.: Sensortraeger Einsatzkraft). With the StEk, it is possible to record LLB exposures in training scenarios with a measuring accuracy satisfying scientific requirements and thus to classify the corresponding LLB load case of the respective weapon system or training scenario. In the test series presented here, the StEk was attached to an operator dummy and exposed to an overpressure load case. The results of the StEk were compared with a pencil probe (PP), which was positioned symmetrically to the StEk in the undisturbed blast propagation area of the SWG. The aim of the test series was to compare the accuracy of the self-sufficient measurement setup StEk with the conventional pressure measurement method (PP). Conventional, market-available blast exposure monitoring device (BEMD) (type: B3 Blast Gauges Gen.6) were used in parallel to check their accuracy. Setup & Method The experimental setup is shown in Figure 1 (left). The StEk system was attached to a dummy placed at a 45° angle to the SWG pressure outlet at a distance of 1 m. A PP was placed axially mirrored. The sensors of the StEk were placed in the typical positions for BEMD. With reference to the incident shockwave, one sensor was placed on the chest (face-on) and one on the shoulder (side-on). The BEMDs were also placed in the same positions. The standalone StEk measurement system is described in the following. The complete measuring chain was realized as one stand-alone, self-sufficient unit. The system is based on a 20-liter backpack system, which contains the power supply, the measuring amplifier and the data acquisition system (DAQ) (Figure 1 (right)). The amplifier has four channels, an integrated 50 kHz low pass filter and is suitable for use with integrated charge piezoelectric (ICP) pressure sensors. A sampling rate of up to 2 MHz can be used Data is stored in a buffer of 64 MS. The computer, a Tablet PC, is attached to the front of the backpack to allow quick access. The pressure sensors are connected to the BNC interfaces on the outside of the housing using coiled BNC cables. The coiled BNC cables allow maximum freedom of movement and reduce mechanical stress on the couplings. In the current configuration, up to four ICP pressure sensors can be mounted on the operator (type: PCB132B38). The pressure sensors are flush-mounted in a 30 mm × 30 mm carrier plate. Results & Discussion Figure 2 (a) shows the overpressure generated by the SWG measured with the PP. The idealized pressure curve can be seen. The second peak is a reflection that occurs within the SWG. Figure 2 (b) shows the pressure measured by the BEMDs. It can be seen that both pressure curves correspond approximately to the idealized pressure curve. This is remarkable because the chest sensor was facing forward and should have a dynamic pressure component caused by the movement of the gas [5]. However, the pressure curves in Figure 2 (b) show the idealized pressure curve that should occur with a side-on overpressure measurement in the undisturbed free field. Therefore, it can be assumed that software modeling is used to generate an idealized pressure curve from the blended pressure curve that is intended to represent the overpressure that will occur. Figure 2 (c) shows the pressure curves of the ICP pressure sensors of the StEk system. It can be seen that the characteristics of the pressure curves were affected by the dynamic pressure component. The shoulder sensor, which, due to the nature of the dummy posture and position, was not exposed perfectly side-on, also showed a dynamic component. Calculations based on the peak overpressures of the PP confirm, that the reflected pressure was visible on the face-on chest sensor [5]. A limiting factor is that the sensor mounts and the dummy itself are subject to mechanical excitation, which probably explains the interference frequency seen in the pressure signal. The test results show the limitations of BEMDs for scientific investigations of weapon systems, as it is assumed that a high degree of modeling of the pressure curves takes place during post-processing. However, as the comparison of the BEMDs with the PP pressure curves shows, the pressure curve fit matches the PP pressure curve sufficiently well. This shows that a scientific measurement system such as StEk should be used initially to investigate and assess the load case from weapon systems or training scenarios in order to capture the real and complete characteristics of the load case. T2 - 8th International Forum on Blast Injury Countermeasures CY - Tokio, Japan DA - 07.05.2025 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Low Level Blast PY - 2025 AN - OPUS4-63318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Description of a measurement setup for LLB exposures in dynamic situations using high-resolution measurement technology N2 - In order to gain an understanding of the Low Level Blast (LLB) exposure of soldiers when using weapon systems, it is necessary to characterize these weapon systems with regard to their overpressure effect [1]. Carrying out static measurements of weapon systems in the rough terrain of firing ranges and training areas poses a challenge for sensitive measurement technology. Furthermore, soldiers are often exposed to LLB in dynamic situations [2]. Therefore, commercially available blast gauges are often used, which, however, are not sufficient for high-resolution measurement of overpressure exposures with academic requirements due to their intended use [3]. Static measurement setups, such as with penile probes, must be used to characterize weapon systems, but they cannot make valid statements about the real load on dynamically behaving soldiers. However, this real load on the soldier is essential in order to be able to adequately assess the potential resulting medical effects. As part of this challenging measurement task, a prototype of a self-sufficient, high-resolution measurement system is presented, which can be used by an operator in dynamic situations without interference. The complete measuring chain was realized as a self-sufficient unit. The system is based on a 20-liter backpack system, which contains the power supply, the measuring amplifier and the measuring card (see Fig. 1, left). The measuring computer is attached to the front of the backpack to allow quick access. The measuring system is capable of recording four channels with a sampling rate of up to 2 MHz. Piezoelectric integrated charge pressure sensors are used as a high-resolution pressure sensor (type: PCB138B32). The pressure sensor is placed on a XX- carrier plates with the dimensions XY × YY. The pressure sensors are attached at the typical positions for Blast-Gauges measurements, like on the left shoulder, on the upper chest and on the back of the head. At the same time, commercial blast gauges are placed at the positions of the pressure sensors to qualify the blast gauges (type: B3 Blast Gauges Gen 6). The measuring system is referred to as a “Sensor Carrier Operator (StEk)”. As part of the functional testing of the measurement system, tests are carried out with hand weapons. For this purpose, a soldier is equipped with the StEk and blast gauges. The handguns used are the pistole P8 (caliber 9 mm) and the long rifle G36 (caliber 5.56 mm). The firing position is standing freehand. In addition, the soldier carried out an examination of the carrying comfort of the StEk as part of the training. Furthermore, it was evaluated whether the measuring chain was adequately integrated into the measuring system. The quality of the pressure measurement was also examined, whereby a direct comparison was made with the blast gauges (see Fig. 1 right). The measurement system presented here enables the combined (static and dynamic) scientific characterization of weapon systems, particularly with regard to overpressure loading. T2 - Research Specialist Meeting HFM 371 (NATO STO) CY - Toronto, Canada DA - 09.04.2025 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Low Level Blast PY - 2025 AN - OPUS4-63323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik T1 - Investigation of Shock Wave Propagation in Soft Tissue Simulants: An Analysis of Organic Gelatin and Synthetic Gel N2 - This study investigates the effects of shock waves on soft tissue simulants, focusing on organic gelatin and a synthetic gel. Although extensive research has focused on the mechanical properties of soft tissue simulants, their behavior under shock wave conditions, such as those caused by blasts, is less understood. As explosives are increasingly used in modern combat scenarios, it is essential to study how shock waves interact with soft tissue. This knowledge is crucial for improving protective equipment and evaluating blast effects on the human body. A two-phase methodology was applied: First, organic gelatin production and synthetic gel composition were analyzed, identifying uncertainties and measuring sound speeds at varying temperatures to align with human tissue properties. Second, simulants were subjected to free-field shock waves, and embedded pressure sensors captured wave propagation, peak overpressures, and propagation velocity. Findings provide comparative insights into shock wave responses of simulants, offering a foundation for future experimental setups. T2 - 34th International Symposium on Ballistics CY - Jacksonville, FL, USA DA - 19.05.2025 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Druckwelle PY - 2025 AN - OPUS4-63321 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeber, Henrik A1 - Grobert, Steffen T1 - Investigation of intracorporeal shock wave propagation using a simplified torso model and a shock wave generator N2 - Blast injuries are among the most common injuries in military operations. Also, in civilian environments, more explosive threats are expected in the future due to emerging conflicts and threats. While the effect of fragments, which is classified as secondary blast injury, could be minimized by police and military personnel’s modern ballistic body protection systems, the effects of shock wave propagation in the body as part of the primary explosion trauma still remain a serious threat needing further research. The detonation-physical processes of highly dynamic pressure changes within the human body, the reflection-related amplification of shock waves at organ-dermis interfaces, and the consequences of injury mechanisms have become more prominent in international research. Various approaches have been used to investigate these aspects. Animal experiments on free field test sites or shock tube setups combined with a subsequent biological evaluation and numerical simulations provided promising results and allowed the discussion of different biomechanical aspects. However, due to poor reproducibility and a lack of short-term dynamic material properties, most research approaches have significant limitations. Laboratory test setups do not represent real-scale high explosive detonation parameters with regards to pressure characteristics, impulse duration and blockage problems. Measured values are interpreted with partly outdated, selective and not validated limit values for overpressures from field tests with animals. This is due to the lack of a validated and comprehensive data set covering a variation of the crucial parameter. Injury mechanisms and their effects have not yet been sufficiently elucidated for the torso and extremities. In order to contribute to the research efforts on the primary explosion effects, the German Federal Armed Forces established an interdisciplinary military medical research project in cooperation of the Bundeswehr Hospital Berlin and the German Federal Institute for Materials Research and Testing (BAM). The aim of the planned investigation is the development of a multidisciplinary method to investigate shock wave behavior in various generic tissue simulants under the most reproducible conditions possible with realistic loads in an experimental test series with short set-up times. T2 - 7th International Forum on Blast Injury Countermeasures CY - Tokio, Japan DA - 17.05.2023 KW - Shock wave generator KW - Blast injury KW - Primäre Explosionswirkung KW - Experimental setup PY - 2023 AN - OPUS4-60045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -