Most structures are complex in behavior even under static loads, and their response to dynamic loads might include additional complications from combinations of elastic and inelastic vibration modes.

A common approach to determine the dynamic response of a structure to some specific loading is to model the structure as a system of finite structural elements and masses connected together at a discrete number of nodal points. If the force-displacement relationships are known for the individual elements, structural analysis can be used to study the behavior of the assembled structure.

It is prudent for practical design purposes to adopt approximate methods that permit rapid analysis of complex structures with reasonable accuracy. These methods usually require that both the structure and the loading be idealized to some degree.

During the 1950s and 1960s, much work was done to develop simple methods for the design of structures subjected to blast loads produced by blast from nuclear weapons. The book by J. M. Biggs which is a revision of an earlier book written by several authors including J. M. Biggs contains an excellent introductory presentation of such methods.

[1] Norris, C. H., Hansen, R. J., Holley, M. J., Biggs, J. M., Namyet, S., Minami, J. K. Structural Design for Dynamic Loads. McGraw-Hill Book Company, Inc. 1959

[2] Biggs, J. M. Introduction to Structural Dynamics. McGraw-Hill Book Company, 1964