The estimation of impact forces based on first principles

Design provision for resistance against impact forces generated by vehicular, or train, collision in codes of practices are typically prescriptive in nature. The basis of the prescriptive clauses is often difficult to trace whereas commonly used analytical models employing energy principles can be overly simplified. Consequently, engineers often find it challenging to make estimates that are outside the scope of coverage of the relevant code clauses. For example, the impact of a boulder rolling downslope is not covered by any loading code not is the accidental dropping of a heavy object. Amid lack of confidence in predicting impact forces with a reasonable degree of accuracies full scale field trials are typically conducted to verify the performance of a built component when subject to certain impact hazard. Full scale experimentations serve the purpose of verifying the adequacy of the design of the component in withstanding a specific impact action, but it would be too costly to have such tests applied repetitively on different components and to cover for different projected impact scenarios. This paper introduces closed form solutions for the prediction of impact forces in the context of civil engineering and construction. The presented solutions were derived from first principles and have been validated by laboratory experimentations thereby giving engineers and product designers, confidence in adapting them to a diversity of engineering applications.