Manish Kumar

IITB Logo Manish Kumar
Assistant Professor

Department of Civil Engineering
Indian Institute of Technology Bombay, Mumbai




Analysis of structures subject to blast loading is like any other dynamic analysis (e.g, seismic analysis), except that higher modes (high frequency) of the structure contributes substantially to the total response. Blast loads can be thought as an impulse loading. The implicit methods of analysis that are most commonly used in earthquake engineering problems are not usually suitable for blast load analysis, because of its inability to capture high frequency response and stability and convergence issues. Explicit methods are used for the blast analysis of structures using softwar programs such as LSDYNA and ABAQUS-Explicit. LSDYNA has a rich library of explicit solvers, and is also famously used to analyze structures and components subject to high strain loadings (e.g, crash test of vehicles, contact problems).
Analysis of structures subject to blast loading involves two steps:

        1. Determination of blast loading (overpressure history) to be applied on a structure
        2. Response estimation of structures subject to blast loads

The first step in a blast analysis is to determine the reflected pressure histories at different locations in the structure. The blast analysis of structures using commercial finite element software programs, like LSDYNA, simulates the blast loading as time-dependent pressure (point or distributed loads) applied directly to the structure. These time-dependent loads can be determined using two methods: 1) Through the charts developed by Biggs and DoD, and 2) Through the computational fluid dynamics analysis. Surface blast loading on the column can be obtained using the software program Air3D, which uses the computational fluid dynamics (CFD) approach. The time and space discretization used in Air3D provides a more realistic approach to simulate blast loading on structures.

Air3D Video Tutorials: Tutorial 1
                                 Tutorial 2

Air3D and ProSAir: ProSAir is successor of Air3D with graphical user interface and provides more capability on modeling relatively irregular structures.

Software homepage:

ConWep: Available to only US Citizens or government contractors

Software homepage:

LSDYNA: Software for finite element analysis. Popular for blast and impact loads in which high strain rates are observed. It provides a range of implicit solvers, that are otherwise not avaiable with other software packages. Pre-post is the pre-processing (model development) tool that comes with LSDyna but its capability is limited and people often use MSC Patran or Oasys for preprocessing which can be used with LSDYNA solver. Learning Materials: Online tutorials
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