TY - JOUR A1 - Camplese, Davide A1 - Scarponi, Giordano Emrys A1 - Chianese, Carmela A1 - Hajhariri, Aliasghar A1 - Eberwein, Robert A1 - Otremba, Frank A1 - Cozzani, Valerio T1 - Modeling the performance of multilayer insulation in cryogenic tanks undergoing external fire scenarios N2 - Multilayer Insulation (MLI) is frequently used in vacuum conditions for the thermal insulation of cryogenic storage tanks. The severe consequences of the degradation of such materials in engulfing fire scenarios were recently evidenced by several large-scale experimental tests. In the present study, an innovative modelling approach was developed to assess the performance of heat transfer in polyester-based MLI materials for cryogenic applications under fire conditions. A specific layer-by-layer approach was integrated with an apparent kinetic thermal degradation model based on thermogravimetric analysis results. The modeling results provided a realistic simulation of the experimental data obtained by High-Temperature Thermal Vacuum Chamber tests reproducing fire exposure conditions. The model was then applied to assess the behavior of MLI systems for liquid hydrogen tanks in realistic fire scenarios. The results show that in intense fire scenarios degradation occurs rapidly, compromising the thermal insulation performances of the system within a few minutes. KW - Multilayer Insulation KW - Cryogenic Vessels KW - Liquefied Hydrogen KW - Liquefied Natural Gas KW - Safety KW - Fire PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599418 DO - https://doi.org/10.1016/j.psep.2024.04.061 SN - 0957-5820 VL - 186 SP - 1169 EP - 1182 PB - Elsevier B.V. AN - OPUS4-59941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Giannakopoulos, Antonios E. A1 - Zisis, Athanasios A1 - Zervaki, Anna D. A1 - Dimopoulos, Christos D. A1 - Platypodis, Efstathios A1 - Eberwein, Robert T1 - Effective elastic moduli and failure mechanisms of a random assembly of thin walled glass microbubbles N2 - In this work a methodology is presented to estimate the elastic properties and failure mechanisms of an assembly of random, brittle microbubbles. The approach is based on the mechanics of frictionless micro-contact between hollow spherical shells by employing relations from classical shell theory and verified by two dimensional axisymmetric Finite Elements. The estimated values are in agreement with available experimental values. Moreover, a granular type analytical homogenization model provides an isotropic elastic constitutive law to be used for the macroscopic deformation of an assembly of glass micro-bubbles when it is compressed by external loads. In addition, approximate estimates are also proposed for two important micro-failure mechanisms of such assemblies that relate either to the splitting or to the buckling of a brittle spherical shell, prior its complete crushing. The results are novel and are expected to enhance the application of glass microbubbles directly in acute thermal insulation problems such as liquid hydrogen storage. KW - LH2 KW - Cryogenic Vessels KW - Insulation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634354 DO - https://doi.org/10.1016/j.ijsolstr.2025.113528 SN - 0020-7683 VL - 320 SP - 1 EP - 11 PB - Elsevier BV CY - Amsterdam AN - OPUS4-63435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -