A method to predict structural dynamic strain based on acceleration signal

Purpose: Structural stress and strain in the key components of aircraft structure is important for structural health monitoring and strength assessment. However, the measure of dynamic strain is often difficult to implement because of the complex test equipment and inconvenient measure points, especially in flight test. This study aims to propose an algorithm of dynamic strain estimation using the acceleration response in time domain to simplify the measure of dynamic strain. Design/methodology/approach: The relationship between the strain and acceleration response is established through the sinusoidal response or modal analysis, which is insensitive to the excitation position and form. A band-pass filter is used to obtain the modal acceleration response, and a filter frequency band selection method is proposed. Then, the dynamic strain at the concerned points can be estimated based on the modal superposition principle. Findings: Simulation and experiment are implemented to validate the applicability and effectiveness of the strain estimation method. The estimated strain results agree well with numerical simulation as well as the experimental results. The simplicity and accuracy of the strain estimation method show practicability for dynamic strength and fatigue analysis in engineering applications. Originality/value: An algorithm of dynamic strain estimation using the acceleration response in time domain is developed. A band-pass filter is used to obtain the modal acceleration response, and a filter frequency band selection method is proposed. The dynamic strain at the concerned points can be estimated based on the modal superposition principle.