TY - CONF A1 - Zur, Malte A1 - Klippel, Alexander A1 - Otremba, Frank A1 - Leder, A. T1 - Numerical simulation and experimental study of cabin-airflow and transport of gas-mixtures in aircraft cargo compartments: model validation N2 - Dangerous goods are transported as air freight in commercial aircrafts. Using plastic jerrycans or plastic containers, liquids or gases can escape by leakage or permeation effects. Prior research by the German Federal Institute for Materials Research and Testing (BAM) showed that the lower explosion limit can be reached when transporting dangerous goods in sea-freight containers under normal transportation situations. This motivated the presented study of the transportation situation of dangerous goods in cargo compartments of commercial airplanes. The scope of this paper is to present the experimental method used for validating a numerical model for CFD (Computational Fluid Dynamics) simulations. The CFD model will be used in a future study to evaluate the potential risk from transporting dangerous goods. The objective of this paper is to present the model mock-up of an aircraft cargo compartment and some examples of three dimensional velocity profiles of the air flow in the mock-up. The velocity profiles are calculated using numerical simulations and measured by Laser-Doppler-Anemometry (LDA) experiments. The mock-up is a generic model of a wide-body aircraft lower deck cargo compartment in a 1:10 scale. Geometry, air exchange rates and inlet as well as outlet flow conditions in the cargo compartment are modeled using realistic boundary conditions. The commercial CFD (Computational Fluid Dynamics) code ANSYS CFX 14 is used for numerical flow simulations applying RANS (Reynolds-Averaged-Navier-Stokes) equations and turbulence models. The turbulence models studied are the renormalization group k-ε-model (RNG), the Reynolds-Stress model by Launder, Reece and Rodi (LRR) and the SST-k-ω-model by Menter (SST). The flow measurement with LDA in the mock-up of a cargo compartment proves to be a feasible method for producing data to validate CFD simulations. Qualitative evaluation of the results shows a good overall agreement between numerical and experimental results. The experimental validation indicates that the implemented CFD model is capable of reproducing the flow situation in the model mock-up. T2 - ASME 2013 Fluids engineering summer meeting - 7th International symposium on flow applications in aerospace CY - Incline Village, Nevada, USA DA - 07.07.2013 KW - Computational fluid dynamics KW - Aircraft cabin air flow KW - Gas mixtures KW - Model validation PY - 2013 SN - 978-0-7918-5555-3 IS - Paper FEDSM2013-16622 SP - 1 EP - 9 AN - OPUS4-30076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birk, A. M. A1 - Otremba, Frank A1 - Gonzales, F. A1 - Prabhakaran, A. A1 - Borch, Jörg-Peter A1 - Bradley, I. A1 - Bisby, L. ED - de Rademaeker, E. ED - Schmelzer, P. T1 - Fire testing of total containment pressure vessels N2 - Full engulfment fire tests have been conducted on total containment pressure vessels filled to 50% and 98 % capacity with water. The tests included an unprotected tank and tanks with two different levels of thermal protection. Total containment in this context means there was no pressure relief device. The tests were conducted with 1/3rd linear scale rail tank cars similar to the DOT 111 tank cars used in North America. The 2.4 m3 model tanks were subjected to 100 % engulfing fires fuelled by liquid propane. The fire heat flux was approximately 80 % by radiation and 20 % by convection with a total heat flux to a cool surface of approximately 100 kW/m2. T2 - 15th International Symposium on loss prevention and safety promotion (loss 2016) CY - Freiburg, Germany DA - 05.06.2016 KW - fire testing KW - hazmat tanks KW - integrity PY - 2016 SN - 978-88-95608-39-6 DO - https://doi.org/10.3303/CET1648047 VL - 48 SP - 277 EP - 282 PB - AIDIC CY - Milano, Italy AN - OPUS4-36361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero Navarrete, José-Antonio A1 - Otremba, Frank T1 - Experimental and theoretical modeling of cargo sloshing during braking N2 - The outputs from a simplified mathematical designed to simulate the liquid cargo-vehicle interaction during an emergency braking maneuver, have been compared with full scale data regarding the sloshing pressure on one of the vehicle chambers. While the specific dimensions and fill level of the fluid within the chamber in the full scale testing, have been considered for the simulation model, the vehicle has been simplified to a straight truck instead of an articulated truck. Nevertheless, the pressure within the chamber is realistically modelled, concerning the maximum and minimum pressures attained, with differences lower than 10% between the simulation and the experimental data. Consequently, these results suggest that the articulation pertaining to the articulated vehicle, does not affect in a significant manner the maximum and minimum values of the pressure within the chamber. A nonlinear model for the suspension, however, could improve the model performance. On the other hand, simulation results suggest that the effect of sloshing could cause a loss of braking efficiency on the order of 7%, when such performance is measured in terms of the stopping time. T2 - ASME 2016 International Mechanical Engineering Congress and Exposition (IMECE2016) CY - Phoenix, Arizona, USA DA - 11.11.2016 KW - Braking event KW - Dynamic pressures KW - Vehicle containers PY - 2016 SN - 978-0-7918-5055-8 VL - 4B SP - Article V04BT05A002, IMECE2016-65698, 1 EP - 6 AN - OPUS4-38400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pötzsch, Sina A1 - Timme, Sebastian A1 - Sklorz, Christian A1 - Skoczowsky, Danilo A1 - Otremba, Frank A1 - Krüger, Simone T1 - Fire protection systems for tanks made of GFRP N2 - The application of lightweight materials for tanks for transportation appears promising. Besides saving weight and therefore transportation costs, new complex geometries that depart from common cylindrical shapes of steel tanks can be manufactured. For transportation of dangerous goods, fire and explosion safety must be maintained to prevent accidents with serious consequences. In this work the fire behavior of lightweight tanks made from glass fiber reinforced plastics (GFRP) with complex geometries is investigated. Pretests on intermediate scale GFRP plates are conducted to identify suitable fire protection systems and surface treatments for composite tanks. The fire resistance is shown to be improved by addition of fire protective coatings and integrated layers. Finally, a complex rectangular GFRP tank with a holding capacity of 1100 liters is fire protected with an intumescent fire coating. The tank is filled up to 80 % with water and burned under an engulfing fully developed fire. It was shown that the intumescent layer could expand before the decomposition of the resin occurred. Furthermore, the adhesion between tank surface and coating was maintained. The structure could withstand a fire for more than 20 min. T2 - ASME International Mechanical Engineering Congress and Exposition (IMECE) 2017 CY - Tampa, Florida, USA DA - 03.11.2017 KW - Lightweight tank KW - Composites in fire KW - GFRP KW - Fire retardants KW - Intumescent layer PY - 2017 SN - 978-0-7918-5849-3 VL - 14 SP - Article UNSP V014T14A017, 1 EP - 6 PB - ASME Press AN - OPUS4-42991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Romero-Navarrete, José A. T1 - Modelling a partly filled road tanker during an emergency braking N2 - A simplified model, based upon physical principles, is proposed the simulate the effect of sloshing on the pressure developed in the tanker chambers. The model has been validated in good extent, with experimental data from full scale testing. The characteristic that mostly affects the pressure developed with the chambers of the tanker is the length of the chamber. While a reduction in this property could decrease the pressure developed within a given chamber, the analysis should take into account an overall approach, as a shortening of the individual chambers would influence the number of chambers necessary to carry a certain amount of product. Consequently, the resulting model could be used to study different effects of the sloshing cargo on the carrying vehicles, including the length and position of the chambers along the tanker body. T2 - WCECS 2017 CY - San Francisco, CA, USA DA - 25.10.2017 KW - Braking KW - Emergency KW - Tanker PY - 2017 UR - http://www.iaeng.org/publication/WCECS2017/ SN - 978-988-14048-4-8 SN - 2078-0958 VL - II SP - 610 EP - 614 AN - OPUS4-42957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Romero-Navarrete, José A. T1 - Analysis of the capsizing of a tanker in the Rhine river N2 - A dynamic simulation model for a tanker ship along the Rhine River has been proposed, based on a simplified computational scheme, involving a two-degree-of-freedom roll plane multibody system, subjected to lateral accelerations estimated on the basis of measured data. The resulting equations of motion are solved through the transition matrix approach. The results suggest that many contributing factors were involved in the capsizing of the ship, including the relatively high speed of the river water and the meandering path of the infrastructure, further affected by dynamic effects derived from the behavior of the payload and from the steering maneuvers performed. T2 - ASME 2017 IMECE CY - Tampa, FL, USA DA - 03.11.2017 KW - Capsizing KW - Tanker KW - Rhine river PY - 2017 SN - 978-0-7918-5837-0 VL - 4A SP - Article UNSP V04AT05A063, 70488 EP - 70495 PB - ASME Press AN - OPUS4-42928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kutz, Philipp A1 - Otremba, Frank A1 - Werner, Jan A1 - Sklorz, Christian T1 - Development of a Single Walled Tank under Cryogenic Conditions made of Composite N2 - The use of glass-fiber reinforced plastic (GRP) can reduce the weight of tanks significantly. By replacing steel with GRP in tanks for gases (propane, etc.) a weight reduction of up to 50 % was reached. In this project not only the material should be optimized, but also the design. Previous tanks consist of a double-walled structure with an insulation layer between the two shells (e.g. vacuum). Goal of this project is to realize a single-walled construction of GRP with an insulation layer on the outside. To determine the temperature dependent material values, two different experiments are performed: In the first experiment, temperature dependent material properties of liquid nitrogen found in literature research are validated in a simple setup. The level of liquid nitrogen in a small jar is measured over the experiment time. Numerical simulation shows the change of nitrogen level with sufficient precision. In the second experiment, a liquid nitrogen is applied on one side of a GRP plate. Temperature is measured with thermocouples on top and bottom of the GRP plate, as well as in the middle of the plate. By use of numerical simulation, temperature dependent thermal conductivity is determined. In the third experiment, a test stand is designed to examine different insulation materials. In this test stand, the insulation material can easily be changed. A numerical simulation, in which the determined material data is used, is performed as well for this test stand. The experiments show, that GRP can be used in cryogenic environments. Multiphase simulations are a suitable tool to describe the energy absorption of thermal energy due to thermal phase change. Results on different insulation materials will follow. T2 - IMECE 2018 CY - Pittsburgh, PA, USA DA - 09.11.2018 KW - Lightweight design KW - Thermal properties of GRP KW - Liquid nitrogen KW - LNG PY - 2018 UR - http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=2722335 SN - 978-0-7918-5214-9 DO - https://doi.org/10.1115/IMECE2018-86365 VL - 9 SP - V009T12A019 PB - ASME AN - OPUS4-47321 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Bradley, I. A1 - Romero-Navarrete, José A. T1 - Boiling Thermohydraulics within Pressurized Vessels N2 - Transport safety depends in great extent of what happens to the cargo once the carrying vehicle derails or rollovers. The exposure of tanks to direct fire is a condition that potentially involves catastrophic consequences. Studying the behavior of the contained fluid under these drastic circumstances, is critical to develop methods and techniques to mitigate the serious consequences of many mishaps. In this paper, the experimental potentials of a Particle Image Velocimetry data acquisition system are described, for providing experimental data that could be used to calibrate mathematical models. As an example of the situations that need to be modelled, an experiment is described concerning the effect of the boundary conditions and protecting devices, on the rate of variation of pressure and temperature of the fluid in a tank exposed to a direct fire. In this regard, the results emphasize the importance of equipping the vessels with both thermal insulation and safety valves. T2 - WCECS 2018 CY - San Francisco, CA, USA DA - 23.10.2018 KW - Thermohydraulic KW - Vessels PY - 2018 SN - 978-988-14049-0-9 SN - 2078-0958 SN - 2078-0966 SP - 538 EP - 542 AN - OPUS4-46419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Romero-Navarrete, José A. A1 - Lozano Guzmán, A. A. T1 - Cargo securement standards and braking maneuvers N2 - There was a need to validate the longitudinal performance required for the cargo securement, as current standards exhibit differences. A model has been proposed in this paper, to simulate the effect of a shifting cargo on the braking efficiency of the vehicle. Results suggest that the braking efficiency can be greater in the case of a shifting cargo, as a result of the uncoupling of the cargo-vehicle systems, implying that similar braking forces are exerted on a reduced mass. The shifting of the cargo can occur as a result of the vibration of the vehicle, that leads to having a diminished friction force to prevent the shifting of the cargo. T2 - International Research Conference CY - Paris, France DA - 29.10.2018 KW - Cargo KW - Securement KW - Maneuvers PY - 2018 SP - 2105 EP - 2108 AN - OPUS4-46423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank A1 - Lozano Guzmán, A. A. T1 - Energy saving potentials of railways instead of roadways: Mexico case N2 - For the last 100 years, Mexico has not invested in new freight railway infrastructure. Consequently, the values of indicators about the use of such Transport mode are poorly compared with those of developed countries such as Germany. T2 - Railways 2018 CY - Sitges, Barcelona, Spain DA - 03.09.2018 KW - Energy saving KW - Potentials KW - Railways KW - Roadways PY - 2018 UR - http://www.railwaysconference.com/ SP - Paper E5.05, 1 EP - 4 PB - Civil-Comp Limited CY - Dun Eaglais, UK AN - OPUS4-45909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank A1 - Lozano -Guzmán, A. A. T1 - Commidities and rail damage N2 - A roll-plane simplified model, representing the suspended body-cargo of a railway car, was developed to simulate thedynamic response of a railway car while subjectedto lateral acceleration derived from its traveling along curved tracks. The model provides the means to calculate the suspension forces, which are supposed to be transmitted to the bogie´s wheelset. For the analysis of the potential effect of such forces on the railway fatigue life, different performance measures were considered, under different concepts. A family of curves were produced to analyze the effect of the height of the center of gravity of the body-cargo system, on the different performance measures. The resultingdiagramswereused to assess the rail damage potentials offour different railway cars. Results suggest that the height of the center of gravity, associated to the different types of railway cars, nonlinearly and strongly affects the fatigue lifeof the rail, with the double stack car being the moreinfrastructure-aggressive. In this respect, experimental evidence should be provided about such remarkable effects, so as to supportsome operational recommendationsthat shouldbe taken to mitigate these effects, including, for example, the regulation of the traveling speed of some vehicles. T2 - IMECE 2018 International Mechanical Engineering Congress and Exposition CY - Pittsburgh, PA, USA DA - 09.11.2018 KW - Commidities KW - Rail KW - Damage PY - 2018 SP - 86008-1 EP - 86008-6 PB - ASME AN - OPUS4-46650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Romero-Navarrete, José A. T1 - A testing rig to study vehicle-track interaction during turning N2 - A testing rig for the measurement of the dynamic loads on the rails due to cargo sloshing,has been proposedin this paper. The system represents a scale-down approach that simulates astraightening maneuver of the railway car after negotiating a turn. As part of the experimental effort, a mathematical model was developed that, oncevalidated, will provide more insights about the potential effect of many other cardesign factors, on the level of stress developed in the raildue to the sloshing cargo.A fundamental output from the testing, will be the objective comparison between the railloads due toa sloshing and a non-sloshing cargo, together with a validated model that wouldallow parametric studies in relation withthe potential effect,of several track and carproperties,on the magnitude of the sloshing forces on the rail. T2 - IEEE/ASME Joint Rail Conference CY - Pittsburgh, PA, USA DA - 18.04.2018 KW - Testing KW - Rig KW - Vehicle-Track KW - Interaction PY - 2018 SP - 1 EP - 6 PB - ASME AN - OPUS4-44816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Lozano Guzmán, A. A. A1 - Otremba, Frank T1 - An active acceleration system to mitigate/avoid underride rear-end crashes N2 - Rear-end crashes involving heavy trucks as the leading vehicle, and cars as the impact vehicle, cause many deaths and permanent injuries to car´s occupants. Measures have been thus taken in the trucks to prevent underride crashes, including the mounting of stiffer underride guards, set at car´s bumper height. In this respect, an active acceleration system(AAS), installed in the truck, could also contribute to mitigate the effects of These crashes, through the decrease of the relative Speed of the vehicles at the instant of the crash. In this paper, an AAS system is proposed, under the principles of ultrasonic sensors and an actuator for the truck´s accelerator mechanism. Simulation results of the operation of this AAS system, suggest that such a system could decrease the relative impact speed around 8% for an initial relative speed of 10 m/s. T2 - 2017 International Conference on Advanced Mechatronic Systems CY - Xiamen, China DA - 06.12.2017 KW - Mitigate KW - Avoid KW - Rear-end crashes PY - 2017 SN - 978-1-5386-2601-6 SP - 329 EP - 334 AN - OPUS4-43400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank A1 - Lozano Guzmán, A. A. T1 - Simulation of liquid cargo – vehicle interaction under lateral and longitudinal accelerations N2 - Amongst the vehicle parameters influencing road safety, the carried cargo plays a critical role in the case of a liquid cargo, posing rollover risk and affecting the available friction forces for braking. While the lateral sloshing of the cargo within the vehicle´s compartments, can be excited when the vehicle negotiates a turn, the longitudinal motion of the cargo derives from changes of speed. The combination of both types of perturbations occurs when the vehicle brakes while negotiating a turn. In this paper, a two-pendulum formulation is used to simulate the lateral and longitudinal behavior of a vehicle when negotiating a braking in a turn maneuver. The suspension forces are thus calculated as the linear superposition of both models. Results suggest that the vehicle roll stability is affected by the cargo sloshing, with increments on the order of 100% in the lateral load transfer, for a 50% filled tank. On the other hand, the dispersion of the travelling speed also affects the lateral stability of such type of vehicles, as a function of the dispersion of the vehicle´s travelling speed. T2 - The 9th International Conference on Computational Methods (ICCM2018) CY - Rome, Italy DA - 06.08.2018 KW - Sloshing cargo KW - Road tankers KW - Pendulum analogy KW - Braking in a turn KW - Lateral load transfer ratio PY - 2018 SP - 88 EP - 102 PB - Scientech Publisher LLC AN - OPUS4-45821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank A1 - Betanzo Quezada, E. A1 - Obregón Biosca, S. A. T1 - The railway transport sustainability in Mexico. Europe and Mexico perspective N2 - The use of railway transportation for satisfying the transport needs of goods in Mexico is less intense than in developed countries, such as Germany. Mexican performance measures based upon the railway length per capita (intensity), or the railway length per square km of the country surface (density), are well behind from corresponding indicators for Germany, in such a way that the length of the railway infrastructure of Mexico should be, at least, doubled in order to reach a comparable intensity rate as that of Germany. In this paper, the benefits from transferring the whole transportation of goods from road to railway, is discussed. The benefits include a remarkable reduction in energy consumption and CO2 emissions. The feasibility for the electrical infrastructure to provide the necessary energy is further shown, while the economic feasibility of such situation is analyzed on the basis of the federal budget of Mexico. According to these estimations, the investment in railway infrastructure is feasible, while the electrical installed capacity is enough to satisfy an all-electric system. T2 - XIV Congreso Internacional de Ingenieria (XIV International Engineering Congress) CY - Querétaro, Mexico DA - 14.05.2018 KW - Railways KW - Trucking KW - Transport externalities KW - Comparative assessment KW - Energy saving potentials PY - 2018 SN - 978-1-5386-7018-7 SP - 1 EP - 4 PB - IEEE AN - OPUS4-45823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gonzalez III, F. A1 - Prabhakaran, A. A1 - Robitaille, A. A1 - Booth, G. A1 - Birk, A.M. A1 - Otremba, Frank T1 - Rail tank car total containment fire testing: planning & test development N2 - Given the frequent incidences of Non-Accident Releases (NARs) of hazardous materials from tank cars, there in an increasing interest in transporting hazardous materials in total containment conditions (i.e., no pressure relief devices). However, the ability of tank cars to meet thermal protection requirements provided in the Code of Federal Regulations under conditions of total containment has not been established. Also, the modeling tool commonly used by industry to evaluate thermal protection, AFFTAC, has not been validated under these conditions. The intent of this effort was to evaluate through a series of third-scale fire tests, the ability of tank cars to meet the thermal protection requirements under total containment conditions, and also, to validate AFFTAC for such conditions. This paper describes the test design and planning effort associated with this research, including the design and evaluation of a fire test setup to simulate a credible, fully engulfing, pool fire that is consistent and repeatable, and the design and hydro-static testing of a third-scale tank specimen. The fire design includes controls on the spatial distribution and temperature variation of the flame temperature, the heat flux, and the radiative balance, to best reflect large liquid hydrocarbon pool fire conditions that may be experienced during derailment scenarios. T2 - JRC2015 - Joint rail conference CY - San Jose, CA, USA DA - 23.03.2015 PY - 2015 SP - 5764, 1 EP - 6 AN - OPUS4-32985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zur, Malte A1 - Otremba, Frank T1 - Numerical simulation and experimental study of cabin-airflow and mass transport of dangerous goods in aircraft cargo compartments N2 - Using plastic jerrycans or plastic containers, dangerous goods are transported as air freight in commercial aircrafts. Liquids or gases can escape by leakage or permeation effects from these plastic containers. The German Federal Institute for Materials Research and Testing (BAM) conducted prior research which showed that the lower explosion limit can be reached when transporting dangerous goods in sea-freight containers under normal transportation situations. The presented study is motivated based on these findings. The research objective of this study is to analyze the transportation situation of dangerous goods in cargo compartments of commercial airplanes. The scope of this paper is to present the experimental method used for validating a numerical model for CFD (Computational Fluid Dynamics) simulations and to present some simulation results of the mass transport of dangerous goods in the cargo compartment. The velocity profiles and the mass transport is calculated using numerical simulations and measured by Laser-Doppler-Anemometry (LDA) experiments. The mock-up is a generic model of a wide-body aircraft lower deck cargo compartment in a 1: 10 scale. Geometry, air exchange rates and inlet as well as outlet flow conditions in the cargo compartment are modeled using realistic boundary conditions. The commercial CFD (Computational Fluid Dynamics) code ANSYS CFX 14 is used for numerical flow simulations applying RANS (Reynolds-Averaged-Navier-Stokes) equations and turbulence models. The turbulence models studied are the renormalization group k-e-model (RNG), the BSL-Reynolds-Stress model (BSL) and the SST-k-co-model by Menter (SST). The flow measurement with LDA in the mock-up of a cargo compartment proves to be a feasible method for producing data to validate CFD simulations. Qualitative evaluation of the results shows a good overall agreement between numerical and experimental results. The experimental validation indicates that the implemented CFD model is capable of reproducing the flow situation in the model mock-up T2 - ICCEE 2015 - International conference on civil engineering and environmental engineering CY - Tokyo, Japan DA - 03.02.2015 PY - 2015 SP - 1 EP - 8 AN - OPUS4-32585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sklorz, Christian A1 - Otremba, Frank A1 - Reich, Franziska T1 - Limit load analysis of pressurized containers N2 - Limit load analysis is a well known method to calculate the allowable design pressure of container components. A limit load of a pressurized container is achieved, when the stress of a wall and the flow stress are equal. In the following paper the transferability of limit load analysis from small scale tank containers up to large scale containers (railway tank) are investigated. Finite element calculations are carried out and compared with experimental results. It can be concluded that the limit load analysis works very well. Furthermore, the yield strength of the material should be used as flow stress. T2 - IMECE 2014 - ASME International mechanical engineering congress and exposition CY - Montreal, Quebec, Canada DA - 14.11.2014 PY - 2014 SN - 978-0-7918-4958-3 SP - Paper 36334, 1 EP - 5 AN - OPUS4-32316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Iancu, O.T. A1 - Otremba, Frank A1 - Sklorz, Christian T1 - Comparison between analytical and finite element calculation for pressurized container N2 - The prediction of the plastic collapse load of cylindrical pressure vessels is very often made by using expensive Finite Element Computations. The calculation of the collapse load requires an elastic-plastic material model and the consideration of non-linear geometry effects. The plastic collapse load causes overalls structural instability and cannot be determined directly from a finite element analysis. The ASME (2007) code recommends that the collapse load should be the load for which the numerical solution does not converge. This load can be only determined approximately if a expensive nonlinear analysis consisting of a very large number of sub steps is done. The last load sub step leading to a convergent solution will be taken as the critical load for the structure. In the instability regime no standard finite element solution can be found because of the lack of convergence of the numerical procedure. Other methods for the calculation of the allowable pressure proposed by the ASME code are the elastic stress analysis and the limit load analysis. In the present paper the plastic collapse load for a cylindrical pressure vessel is determined by an analytical method based on a linear elastic perfectly plastic material model. When plasticity occurs the material is considered as incompressible and the tensor of plastic strains is parallel to the stress deviator tensor. In that case the finite stress-strain relationships of Henkel can be used for calculating the pressure for which plastic flow occurs at the inside of the vessel wall or in the case of full plasticity in the wall. The analytical results are fully confirmed by finite element predictions both for axisymmetric and high costs three dimensional models. The analytical model can be used for fast predictions of the allowable load for the design of a large variety of pressure vessels under safety considerations. The accuracy of the predicted collapse load largely depends on the quality of the temperature dependent wall material data used both in the analytical and numerical calculations. T2 - IMECE 2014 - ASME International mechanical engineering congress and exposition CY - Montreal, Quebec, Canada DA - 14.11.2014 PY - 2014 SN - 978-0-7918-4958-3 SP - Paper 36106, 1 EP - 5 PB - Amer soc mechanical engineers CY - New York, NY, USA AN - OPUS4-32317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erhard, Anton A1 - Otremba, Frank T1 - Nondestructive testing and fracture mechanics N2 - Nondestructive Testing (NDT) and fracture mechanics are two different disciplines in applied engineering science. Both areas are very important for the evaluation of the component integrity. Unfortunately the technical understanding in both disciplines is not identically, what lead to misunderstandings. In the present paper, the basic ideas about fracture mechanics and the input parameters coming from the NDT side are explained, concerning the integrity evaluation of the components. The widely used NDT methods are magnetic particle, dye penetrant, electrical eddy currents, radiography and ultrasonics. But not all of these common NDT methods can deliver parameters satisfy the fracture mechanics requirements. The first two can detect only surface-breaking or immediately sub-surface defects. Eddy current can also find defects in deeper sub-surface layers, while radiography and ultrasonics can also find embedded, remote defects. These three methods have furthermore a high potential for defect sizing and are therefore predestined to provide fracture mechanics input parameters. At the example of steam generator tube inspection the interplay of eddy current and fracture mechanics as related to tube integrity will be explained. T2 - 5th International CANDU In-Service inspection workshop and NDT in Canada 2014 conference CY - Toronto, Ontario, Canada DA - 16.06.2014 KW - Eddy current KW - Steam generator tube inspection KW - Component integrity KW - Fracture mechanics PY - 2014 SP - 1 EP - 12 AN - OPUS4-30907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -