Numerical and Experimental Modal Analysis of Damaged Soft Panel (Hydrogel) Structure using Nonlinear Material Model

This study presents a detailed investigation of the modal frequency responses of agar-based hydrogel flat components using both numerical and experimental approaches. A finite element-based numerical model is developed, incorporating the nonlinear mechanical behaviour of the hydrogel material along with appropriate geometric dimensions and boundary conditions. The first ten frequency modes are evaluated for both damaged and undamaged panels. Experimental tests have also been performed to validate the proposed numerical results with an average deviation of 6.124%, further confirming the model's reliability and accuracy. Additionally, variable parametric studies have investigated the impact of varying aspect ratios, thickness ratios, and boundary conditions on the natural frequencies of the hydrogel flat components. Due to damage, the frequency decreases by up to 10% compared to intact conditions. The influence of damage on structural integrity and the local stiffness degradation highlights the sensitivity of the hydrogel's frequency behaviour.