Open Access

This study investigates the validation and calibration of the MAT_MM_CONCRETE material model for simulating the blast response of reinforced concrete slabs. A comprehensive experimental campaign, including blast loading measurements, structural response monitoring, and damage assessment, was used to benchmark numerical simulations performed with IMPETUS. The results show that the response of the model is governed primarily by the transition strain limits, while some commonly adjusted fracture-energy parameters may have only limited influence under specific conditions. It is also shown that vibrations, deformations, and crack patterns are key parameters for validation. The work highlights the importance of selecting physically relevant calibration parameters and validating simulations against multiple experimental observables to achieve reliable blast assessments.

The German federal authorities responsible for human and environmental safety, and metrology – the German Environment Agency (UBA), the Federal Institute for Occupational Safety and Health (BAuA), the German Federal Institute for Risk Assessment (BfR), the Federal Institute for Materials Research and Testing (BAM), and the National Metrology Institute (Physikalisch-Technische Bundesanstalt, PTB) - are accompanying the rapid pace of innovation of advanced materials with a long term research strategy focusing on safety research needs from a regulatory perspective. The strategy builds on former joint research strategies on nanomaterials and advanced materials and highlights current research priorities to enable regulatory preparedness for material innovations and better connect safety research with innovation research.

Due to the properties of shock tubes, their classification as dangerous goods is under discussion. Often, these products cannot be excluded from Class 1 according to UNMR criteria. Therefore, in addition to a definition of these items, it is proposed that a specific entry for this product group be included in the regulations.

This presentation uses a specific example to examine a product group that contains reactive pyrotechnic compositions with the aim of achieving an explosive effect. Special classification aspects for such products will be discussed (closed session of the meeting).

Blast testing finds its implementation in several applications, e.g. for the purpose of investigation into accidental or intentional explosions, or for an assessment of the level of protection provided by a certain structural configuration. Analytical and/or semi-empirical methods are generally limited to preliminary assessments prior to blast testing. Applications of numerical simulations with hydrocodes coupled with finite element methods (FEM) can only reduce the amount of blast testing required, as these necessitate fulfillment of the fundamental prerequisites of model verification and that of model validation. Field tests are implemented for contact detonations as well as near-field blast scenarios and shock tube tests for far-field blast scenarios. However, these can be extremely resource intensive. Reliable small-scale experiments are a promising alternative. The concepts of dimensional analysis and similarity based on Buckingham’s Π-theorem (1914) have been applied in different fields. For applications to the phenomenon of shock wave propagation, Hopkinson-Cranz or cube-root scaling is a well-established concept. When it comes to scaling the structural response, research has predominantly focused on structures made of metallic materials. Scaled investigations with concrete or reinforced concrete (RC) structures remain limited. The lack of even the most basic guidelines (far from any ‘standardized scaling methods’ for blast tests) show that scaling as a method is not yet established in blast effects analysis. In this preliminary study, we present a systematic approach and evaluation of scaling of blast effects analysis for RC slabs in order to develop guidelines for resource efficient testing methods. We study the blast scenario at two different scales. The focus of these investigations has been on evaluation of scaling of dynamics using pressure sensors, acceleration sensors and fiber optic sensing cables for distributed acoustic sensing (DAS). Further, the resulting plastic behavior upon blast is characterized by distributed strain sensing (DSS) along the same cables.