Some approaches to modeling blast wave impact on structures in LIRA-FEM

The article is devoted to the methodology of modeling the calculation of structures for the action of dynamic loads caused by the impact of a blast wave and considers in detail the process of applying these dynamic loads to building structures in the LIRA-FEM software. This article describes the main stages of the calculations, starting from the calculation of the main parameters of the blast wave to the collection and application of dynamic loads to structural elements to perform the calculation by the direct dynamic method. One of the key aspects of the article is to determine the main parameters of the blast wave that affect the magnitude and nature of the effects of the explosion loads. These parameters include pressure peak, blast wave duration, blast wave impulse, and wave front shape. The article discusses the typical values of these parameters depending on the explosion conditions, such as the type of explosive and the distance to the explosion epicenter. The preference is given to modeling the effect of explosive loads on a structure as a dynamic impact. Such an impact can lead to significant deformations of structures and reveal additional features of the structure. The article also describes the sequence of analysis of structures for explosive loads, which includes several stages. The first step is to determine the type of explosive device and its parameters, as well as the distance from the epicenter of the explosion to the structure. Next, the static load (pressure) from the blast wave is calculated and applied to the structural elements. The next step is to set the dynamic parameters of the blast wave, which are determined using special methods or regulatory documents. At the final stage, calculations are performed using the Time Dynamics module of the LIRA-FEM software package, which allows taking into account dynamic effects and assessing the behavior of the structure during the blast wave action.