Determining the Progression of Damage in Materials Subjected to Sustained Random Loads Using an Adaptive Finite Impulse Response Approach

It is often important to establish the ability of materials to withstand dynamic loads. This ability is best determined by subjecting the elements to sustained random loads under controlled conditions. It is during these fatigue endurance tests that the loss of structural integrity of a material or an element needs to be quantified. The research presented herein uses a recently developed continuous structural integrity assessment technique to evaluate variations in the mechanical properties (namely stiffness) of materials. The effectiveness of the technique was evaluated by undertaking controlled experiments, during which damage was simulated by varying the stiffness (in this case the length of a cantilever beam) of a physical single degree‐of‐freedom vibratory system subjected to random base excitation. Additional experiments where materials were allowed to naturally decay (structurally) under sustained random loads were also performed. Overall, the results presented in this study indicate that the technique can be a practical and effective tool for detecting small variations in the structural integrity of materials subjected to sustained random loads.