Abstract: To address the noise issue caused by resonance excitation of the natural frequency in accumulator structures, investigates the influencing factors of natural frequency in accumulator structures. Based on single-degree-of-freedom system theoretical analysis, the natural frequency is primarily determined by the structural “stiffness” and “mass”. A finite element numerical simulation model was established with less than 5% error between theoretical calculations and experimental measurements. Characteristic dimension sensitivity analysis reveals that bracket feature dimensions primarily affect the upper natural frequency: increasing bracket thickness, width and height enhances bracket stiffness and raises the upper natural frequency, with sensitivity ranking: bracket thickness > bracket width > bracket height. Bend and cylinder wall thickness dimensions mainly influence the lower natural frequency: increasing bend wall thickness, reducing bend length and thinning cylinder wall thickness improve bend stiffness and reduce cylinder mass, thereby increasing the lower natural frequency, with sensitivity ranking: bend wall thickness > bend length > cylinder wall thickness. In a practical case study with largely finalized product structure, thickening the bend wall thickness—a minimal structural modification—effectively adjusted the natural frequency and resolved the accumulator noise issue.

Key words: Accumulator, Natural frequency, Mass, Stiffness, Finite element method