TY - THES A1 - Lengas, Nikolaos T1 - Parameter study of impact targets in the drop test of packaging for dangerous goods N2 - Within the transportation chain, impact loading of dangerous goods packagings can happen. Thus, a package’s resistance against mechanical damage needs to be assessed. In the context of dangerous goods transport, drop tests are used for damage assessment as a part of packaging approval. Hence, a horizontal, flat unyielding surface must be provided to ensure maximum damage on impact and univocal test results. Leading adopted regulations like ADR/RID reference ISO 2248 to specify the requirements for the impact surface. The main requirement states that the impact surface must belong to an impact target with a mass at least 50 times higher than that of the heaviest package to be tested. However, many manufacturers in Germany, especially manufacturers of fibreboard boxes, do not have their own testing device with the required mass ratio for the drop test. Furthermore, the necessity of requirement revision has been addressed at UN level. It is unclear if mass ratio is the decisive criterion or if alternative design parameters can be defined to guarantee rigidity of the impact surface. The focus of the research reported in this thesis lays in the development and implementation of an analysis and testing concept for a comprehensive investigation of impact targets in drop testing. To this end, an experimental setup consisting of regulation compliant model impact targets is used in drop tests with two packaging types of significantly different mechanical properties. The variation of drop test parameters, such as the mass ratio, provides new insights into their respective significance in the drop test outcome. In addition, experimental findings are enhanced with numerical Finite-Element (FE) analyses to propose new improved criteria which incorporate all relevant influencing factors. In this way, firstly, critical impact target designs can be identified, and secondly, the kinetic energy of a real impact target in a drop test can be reliably approximated and compared to the respective theoretical threshold derived from a worst-case assumption. Thus, the rigid mass ratio currently specified in ISO 2248 can be regarded obsolete. The results of this work are highly beneficial for industrial application since they form the basis for introducing a standardized method for evaluating impact targets, replacing the 50 times mass ratio requirement. This would enable manufacturing and testing facilities to ensure a uniform level of safety assessment and to avoid the considerably high construction costs of impact targets with mass ratio of 1:50 in relation to packaging gross masses of several hundred kilograms. Hence, to make the results attained under laboratory conditions usable in practical application, preliminary investigations of the mechanical response of installed impact targets are conducted. For this purpose, important factors such as the interaction between impact target and ground in dynamic impact testing conditions are examined using validated FE models to establish an evaluation method. The investigations aim to create the basis for the revision of ISO 2248 and to define a standardized reference method for impact target characterization. KW - Drop test KW - Structural dynamics KW - Dangerous goods packaging KW - Mass ratio KW - Finite-element-method PY - 2025 DO - https://doi.org/10.14279/depositonce-24333 SP - 1 EP - 189 CY - Berlin AN - OPUS4-64090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick‐Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, Manfred W. T1 - Drop Test Simulation of Packaging for Dangerous Goods: An Investigation of Appropriate Drop Height Adjustment in Case of Deviating Packaging Gross Mass N2 - In the approval process of dangerous goods packagings, drop tests onto a flat, essentially unyielding surface are used to assess resistance against mechanical damage. International adopted regulations like ADR and RID define filling good dependent drop heights and filling degrees whilst the user needs to define the maximum gross mass to be tested and approved. Maximum packaging gross mass is defined conservatively and not reached in practice. To meet the defined gross mass in testing, using additives is permitted. However, in some cases, additives are not desirable due to packaging design or filling substance properties. This leads to deviations from the initial gross mass definition. Hence, a certain drop height adjustment is necessary to achieve the required impact loading. Laboratories frequently adjust drop height assuming a perfectly elastic collision that is inaccurate. Appropriate adjustment is not trivial due to energy conversion processes, for example, plastic deformation. In this work, a test stand KW - Corrugated fibreboard box KW - Dangerous goods packagings KW - Drop test KW - Impact target KW - Mechanical response KW - Structural dynamics PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614138 DO - https://doi.org/10.1002/pts.2858 SP - 1 EP - 18 PB - Wiley AN - OPUS4-61413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Mair, Georg W. A1 - Müller, Karsten A1 - Sklorz, Christian A1 - Wang, Bin A1 - Natasya, Riska T1 - Overview of experimental testing at BAM: Hydraulic pressure, drop and fire tests N2 - Safe onboard storage is clearly one of the greatest challenges for the hydrogen economy. Even if hydrogen vehicles offer better efficiency, technological barriers remain for short-term implementation. Hydrogen storage difficulties stem from its low density, necessitating very high pressure for storage. In addition, the weight, volume, efficiency, safety of storage as well as the cost of the hydrogen must be considered. Safety is of paramount importance for deployment of hydrogen technologies as it is flammable in a wide range of concentrations with air, more sensitive to ignition due to its low minimum ignition energy, deflagrates faster due to higher burning velocity, and is prone to deflagration-to-detonation transition. Various safety measures must be implemented in order to prevent accidental leakage and ensure inherent safety. Today, the strategy of the OEM’s prioritises the development of a single electrical drivetrain platform where the battery pack is mounted in the underbody of the vehicle. The automotive industry aims to use this same space for hydrogen storage systems, with the expectation that such conformable hydrogen storage systems will be available in the next 3-5 years. The main innovations of BAM’s specialist divisions 3.5 and 8.6 in this project are, firstly, the integration of optical fibres in the filament winding of complete pressure to gain a deeper understanding of the structural behaviour under the different hydraulic and pneumatic loading conditions, and secondly, the development of a fire test platform to test the assembly of 9 tubular vessels under the fire test requirements of GTR13. Therefore, a wind damping and splinter-protecting cage was built from protection modules specifically developed for this project. Extensive safety-related tests are to be carried out at BAM during the project period. T2 - Stakeholders’ Meeting CY - Brussels, Belgium DA - 26.09.2024 KW - Composite pressure vessel KW - Drop test KW - Hydraulic pressure test KW - Fire test PY - 2024 AN - OPUS4-61167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos T1 - Drop test simulation of packaging for dangerous goods: Investigation of appropriate drop height adjustment N2 - In the approval process of dangerous goods packagings, drop tests onto a flat, essentially unyielding surface are used to assess resistance against mechanical damage. International adopted regulations like ADR and RID define filling good dependent drop heights and filling degrees whilst the user needs to define the maximum gross mass to be tested and approved. Maximum packaging gross mass is defined conservatively and not reached in practice. To meet the defined gross mass in testing, using additives is permitted. However, in some cases, additives are not desirable due to packaging design or filling substance properties. This leads to deviations from the initial gross mass definition. Hence, a certain drop height adjustment is necessary to achieve the required impact loading. Laboratories frequently adjust drop height assuming a perfectly elastic collision which is inaccurate. Appropriate adjustment is not trivial due to energy conversion processes, e.g., plastic deformation. In this work, a test stand is developed for measuring the change in kinetic energy of different packaging designs and filling substances in regulative drop tests. The experimental results are used to validate finite-element (FE) models so that packaging properties can be varied in simulated drop test scenarios. The findings intend to describe the appropriate drop height adjustment of the respective packaging with same design but deviating gross mass to produce comparable mechanical response. The results are highly beneficial for testing laboratories, approval issuing authorities and packaging institutes confronted with the problem of testing packages with gross masses other than those to be approved. T2 - 24th IAPRI World Conference CY - Valencia, Spain DA - 17.06.2024 KW - Dangerous goods packagings KW - FEM KW - Drop test KW - Mechanical response PY - 2024 AN - OPUS4-60607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - FEA of the mechanical response of installed impact target foundations in drop tests of dangerous goods packagings N2 - Packagings for the transport of dangerous goods need to meet special requirements to get an approval. This includes free fall drop testing onto an essentially unyielding surface as a means to assess a package’s resistance to mechanical damage. A main requirement for drop tests is that the impact target’s mass shall be at least 50 times that of the heaviest package to be tested. Nevertheless, many manufacturers do not possess foundation structures with the required mass ratio. Previous evidence highlights that the mass ratio is not a decisive criterion on its own. Parameters such as the impact target foundation’s connection and the impulse experienced by the impacting object are essential as well. However, these factors are not easily verifiable since experimental measurements are not possible at most facilities. The objective of this work is to provide a detailed analysis on the interaction between impact target foundation and subgrade in dynamic impact testing using validated finite-element (FE) models. This research is highly beneficial for industrial application since it allows manufacturers to make informed predictions about the mechanical response of installed impact target foundations. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2012 KW - Dangerous goods packagings KW - Drop test KW - Foundation KW - Structural dynamics PY - 2023 AN - OPUS4-58213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Improved criteria for evaluating impact targets in regulative drop tests of dangerous goods packagings N2 - For dangerous goods packagings, drop testing onto an essential unyielding target can be used to assess the mechanical resistance to impact loads. Adopted regulations like ADR/RID require that the impact surface provided shall be integral with a mass at least 50 times than that of the heaviest package to be tested. The problem is that many manufacturers do not possess impact targets that satisfy the required 50 times mass ratio for regulative drop tests during series production. The objective of this work is to verify existing and define improved criteria for impact target structures based on systematic investigations. Previous evidence highlights the relevance of other parameters in addition to the mass ratio. Therefore, in this research, a variation of drop test parameters was carried out experimentally. Furthermore, numerical vibration analysis was applied to investigate the deformability of the impact surface. The results conclude that the mass ratio of 1:50 cannot be defined as a decisive criterion. In order to determine the influence of further drop test parameters, the research findings were used to validate a parametric model which assesses impact target deflection. An approximation quality of over 90 % was achieved. As a result, new evaluation criteria are proposed. Firstly, a method for identifying critical impact target designs is provided. Secondly, a new comprehensive formula compares the approximated maximum deflection of a real impact target to the respective theoretical threshold derived from a worst-case assumption. In practice, this leads to great advantages in the evaluation of already installed impact targets for dangerous goods packagings. T2 - 31st IAPRI Members’ conference CY - Mumbai, India DA - 22.05.2023 KW - Drop test KW - Structural dynamics KW - Dangerous goods packagings KW - Impact target KW - Vibration analysis PY - 2023 AN - OPUS4-57715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Improved criteria for evaluating impact targets in regulative drop tests of dangerous goods packagings N2 - For dangerous goods packagings, drop testing onto an essential unyielding target can be used to assess the mechanical resistance to impact loads. Adopted regulations like ADR/RID require that the impact surface provided shall be integral with a mass at least 50 times than that of the heaviest package to be tested. The problem is that many manufacturers do not possess impact targets that satisfy the required 50 times mass ratio for regulative drop tests during series production. The objective of this work is to verify existing and define improved criteria for impact target structures based on systematic investigations. Previous evidence highlights the relevance of other parameters in addition to the mass ratio. Therefore, in this research, a variation of drop test parameters was carried out experimentally. Furthermore, numerical vibration analysis was applied to investigate the deformability of the impact surface. The results conclude that the mass ratio of 1:50 cannot be defined as a decisive criterion. In order to determine the influence of further drop test parameters, the research findings were used to validate a parametric model which assesses impact target deflection. An approximation quality of over 90 % was achieved. As a result, new evaluation criteria are proposed. Firstly, a method for identifying critical impact target designs is provided. Secondly, a new comprehensive formula compares the approximated maximum deflection of a real impact target to the respective theoretical threshold derived from a worst-case assumption. In practice, this leads to great advantages in the evaluation of already installed impact targets for dangerous goods packagings. KW - Corrugated fibreboard box KW - Dangerous goods packagings KW - Drop test KW - Impact target KW - Mechanical response KW - Steel drum KW - Structural dynamics PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576985 DO - https://doi.org/10.1002/pts.2759 SN - 0894-3214 SP - 1 EP - 14 PB - John Wiley & Sons Ltd AN - OPUS4-57698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lengas, Nikolaos A1 - Johann, Sergej A1 - Kadoke, Daniel A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Zehn, Manfred W. T1 - Damage assessment of complete, filled fibreboard boxes in regulative vertical impact tests by dropping N2 - Due to the high damping mechanical properties of fiberboard materials, corrugated fiberboard boxes are widely used as transport packagings of dangerous goods. Since there is risk of vertical impact within the distribution system, drop tests are performed as design type tests to assess a package’s ability to withstand damage. In this context, however, little is known regarding the transient mechanical response of a filled fiberboard box. The reason is that the nature of the packaging material presents challenges in identifying the deformation mechanisms experimentally. The aim of this work is to provide a framework for predicting the damage resistance of complete, filled corrugated fiberboard boxes which are ready for transportation. Therein, drop test finite-element simulations are used and validated by experimental results. These numerical calculation models are a valuable tool for virtual product development and contribute to the optimization of the design cycle. KW - Finite-element-method KW - Digital image correlation KW - Dangerous goods packagings KW - Corrugated fiberboard box KW - Drop test PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575050 DO - https://doi.org/10.1016/j.matpr.2023.04.679 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-57505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos T1 - Damage assessment of complete, filled fibreboard boxes in regulative vertical impact tests by dropping N2 - Due to the high damping mechanical properties of fibreboard materials, corrugated fibreboard boxes are widely used as transport packages of dangerous goods. Since there is a hazard of vertical impact within the distribution system, drop tests are performed as design type tests to assess the package’s ability to withstand damage. However, there is little information in this context regarding the mechanical response of a filled fibreboard box. This work aims to propose a concept utilizing experimental drop test results by means of finite-element (FE) analyses in order to predict the damage resistance of complete, filled corrugated fibreboard boxes which are ready for transportation. T2 - 38th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Poros Island, Greece DA - 20.09.2022 KW - Drop test KW - Dangerous goods packagings KW - Corrugated fibreboard box KW - Finite-element-analysis KW - Explicit transient simulation KW - Crash simulation PY - 2022 AN - OPUS4-55845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos T1 - Bewertung von Fallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen N2 - Bericht über die Vorgehensweise der systematischen Untersuchungen zur Entwicklung angepasster Kriterien für die Bewertung von Aufprallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen T2 - ERFA Verpackungen CY - Berlin, Germany DA - 22.09.2022 KW - Fallprüfung KW - Aufprallfundament KW - Gefahrgutverpackung KW - Fallfundament KW - Mchanische Sicherheitsprüfung PY - 2022 AN - OPUS4-55843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -