Multiple-Input Multiple-Output (MIMO) Acceleration Test Specification Optimization for Improved Strain Replication

The goal of dynamic testing is to replicate the loads and stresses a system experiences in the field within a laboratory setting. It is standard practice to match acceleration specifications during vibration testing, assuming this ensures the component’s suitability for real-world application. Multi-Input Multi-Output testing was developed to better represent field loading patterns by controlling multiple acceleration locations on a system. However, discrepancies between field and laboratory boundary conditions make impedance matching more complex and hinder accurate reproduction of strain and stress responses in laboratory environments. Consequently, inaccuracies in stress field replication may persist, even when accelerations are matched at multiple locations. This thesis proposes a novel acceleration specification optimization technique that uses a Modal Decomposition and Expansion methodology to account for impedance differences between field and laboratory environments, which leads to a more accurate replication of strains at critical locations for the first three significant modes in a structure.