Structural similitude for flat laminated surfaces

Due to special characteristics of advanced reinforced composite materials, they require extensive experimental evaluation. Thus, it is extremely useful to use available experimental data of specific structural systems or of small-scale models to predict the behavior of all similar systems, especially large. This study investigates problems associated primarily with the design of scaled-down models. Similitude theory is employed to develop the necessary similarity conditions. Scaling laws provide the relationship between a full-scale structure and its scale models and can be used to extrapolate the experimental data of a small, inexpensive, and easily tested model into design information for the large prototype. Both complete and partial similarity is discussed. The developed method is demonstrated through analysis of the cylindrical bending of orthotropic laminated beamplates subjected to transverse loads, buckling of symmetric laminated cross-ply rectangular plates subjected to uniaxial compression and analysis for the vibration response of cross-ply symmetric configurations. For the case of beamplates, experimental data are available for a number of configurations and are used to test the validity of the methodology. In the buckling and vibration studies, the demonstration is totally analytical. In these cases, a small-scale model is theoretically analyzed, the theoretical predictions are treated as if they were experimental results, the scaling laws are then used to predict the behavior of the large prototype and finally these predictions are compared to the theoretical values of the prototype in order to test the validity of the method. All was accomplished with considerable success.