Drop Testing of Packages Using Scale Models·

International and U.S regulations require that a package used for transporting radioactive materials maintain containment, shielding and subcriticality of its contents. Regulations require that the package undergo a number of tests under a set of normal and accident conditions (including a number of drop or impact conditions) to demonstrate the package's ability to meet these requirements. The impact conditions involve either (I) the package dropping freely from a height onto a target or (2) a target dropping freely from a height onto a package. Testing large packages is expensive and is often limited by the availability of test facilities. One popular alternative is to test reduced-scale models. This paper examines the feasibility and difficulties of using scale models for the required drop tests. By analyzing the factors governing the impact responses and failure modes, the paper systematically establishes five general requirements for scale-models used for drop testing. They are the geometric, kinematic, dynamic, gravitational, and material similarities between the scale model and the prototype. For each of the requirements, the paper identifies the mathematical scaling laws. The impossibility of obtaining a general solution for all the scaling laws is demonstrated. However, by ignoring various effects, the paper produces several practical scale models for various applications. Impact analysis results are used to demonstrate the expected performance of the models. Past applications of the models are identified by citing existing publications.