Blast is ail interesting dynamic phenomenon as it causes modes of failure that are not seen in typical dynamic loading scenarios. Menkes et al1 had experimentally shown that for beams the failure mode shifts from a moment dominant to shear dominant with increase in blast intensity.A numerical model based on Finite Element Methods was developed to analyze the response of beams subjected to.blast loading. Three beam theories namely Euler-Bernoulli, Timoshenko and Reddy-Bickford were used for this purpose and explicit scheme was used for time integration. Numerical model was reasonable in depicting the expected shift in failure modes.