Aluminum-reinforced epoxy models

This paper discusses test applications, fabrication methods, and stress-analysis techniques which have been developed on aluminum-filled epoxy models. The use of aluminum-reinforced epoxy models as a preliminary design tool has found extensive application in the development and modification of aircraft structures and related components. The range of uses has varied from the effects of adding or removing material in order to optimize a design, to a full experimental stress analysis of a complete part under multiple-loading conditions. This technique when used in conjunction with photoelastic coatings and/or strain gages, provides complete kinematic and design information before production, tooling, manufacturing and engineering expenses are incurred. The paper discusses machined and molded models, material properties including time-modulus criteria and viscoelastic-creep phenomena, model rework, photoelastic-coating reinforcement and strain-gage effects.