Iterative method for real-time Hybrid testing: application to a cantilever beam with two interface degrees of freedom

TL;DR

This paper introduces an iterative real-time hybrid testing method that improves interface synchronization for structures with periodic responses, demonstrated on a cantilever beam prototype relevant to aircraft wing testing.

Contribution

The paper presents a novel iterative approach for real-time hybrid testing that enhances stability and accuracy in structures with interface degrees of freedom, especially under periodic excitation.

Findings

Achieves good interface synchronization across various scenarios

Handles challenges in measuring interface forces and controlling continuous structures

Maintains stability despite small time delays

Abstract

In this paper, an iterative method for real-time hybrid testing (RTHT) is proposed. The method seeks to iteratively balance the interface conditions between the physical and numerical substructures by controlling the periodic demand of the actuators. It is then suitable for RTHT of structures undergoing a periodic response, e.g. structures excited at resonance. We demonstrate the capabilities of the method on a cantilever beam in bending motion with two degrees of freedom at the interface, which we use as a prototype for future testing of aircraft wings. We show that a number of challenges arise in these settings, such as the difficulty in measuring interface forces while controlling a continuous structure and the instability of the hybrid test for small time delays. Classical RTHT strategies could produce inaccurate or unstable outcomes, whereas the proposed method is able to attain very good interface synchronisation in a wide range of tested scenarios.