The influence of membrane air spring cord parameters on the vertical stiffness

The membrane air spring possesses the advantage of variable vertical stiffness. However, under limited vertical installation space, further investigation is required to analyze how variations in the rubber airbag cord parameters influence the vertical stiffness of membrane air springs. A finite element model of a specific membrane air spring was developed. Under a compression displacement of 40 mm, the effects of parameters such as the number of rubber airbag cord layers, cord spacing, cord angle, and cord cross-sectional area on vertical stiffness were examined. The results indicate that vertical stiffness decreases with an increase in cord spacing or cord angle, but increases with greater cord cross-sectional area or number of cord layers. Subsequently, the orthogonal experimental method was applied to construct an L 9 (3 4 ) orthogonal table, and the influence of the four cord parameters on the vertical stiffness of the membrane air spring under 40 mm compression displacement was analyzed. The findings revealed that vertical stiffness is least affected by cord angle and most affected by the number of cord layers. The variation trend of vertical stiffness was determined by fitting the optimal parameter combination. Finally, the combination of four cord parameters yielding the maximum vertical stiffness was evaluated when the compression displacement increased to 50 mm, providing a reference for air spring configuration design in confined spaces.