Airspring Bellow Lab Report

he airspring bellow, which are here considered, consist of two cross wound fabric layers, which are embedded into rubber matrix. The bellow was tested by the life duration tests and benchmarking tests in the experimental workshop. In the benchmarking results, there were various breakages observed in the case of failed airspring bellow.
Here the figure shows the result of the benchmarking tests and the failure mode of the airspring bellow from the rolling lobe area and the second figure shows the results which are computed analytically by the finite element method. Here, an Abaqus based simulation tool is also available for the airspring bellow considering both macro and micro mechanical analysis. Earlier simulation results of micro model identifies

The next chapter 1.4 will give brief idea about airspring bellow.
1.5 Airspring bellow
The bellow is produced from pre-prepared mixture of rubber and fabric cords. Here, two cord layers are embedded in the rubber matrix. A special mixture consisting of the elastomers and the strength improving additives is used to manufacture the required rubber. Whereas, the idea of bellow is to increase reinforcement layer over the length of the versatile (flexible member) member of the airspring. The arrangement of the cords layer is designed in a way that cords layers are inclined relative to the peripheral direction of the versatile members. Here the Fig.1,3 shows that rolling bellow relates to the roll-off piston, which is typically made from metal or plastic[19].
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1.5. Airspring bellow
Figure 1.3: Airspring section cut[19, 16]
The bellow is positioned as a central element into the airspring. It contains mainly five layers in the rubber matrix. Namely inner rubber layer, inner cords layer, middle rubber layer, outer cords layer, outer rubber layer starting from bottom to top respectively. The cyclic movement of

The flexibility of the airspring change the effective surface according to every travel of the airspring based on the design principle[21]. The Fig.1,6 shows three different position of the airspring during the travelling from Jounce to
Rebound.
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1.7. Physical characteristics of the airspring
Figure 1.6: Kinematic position of the airspring
The effective surface area is the area, from where airspring can transfer the air inner pressure through the airspring bellow wall to the vehicle parts. it is denoted by Aef f [21].
Effective surface of the airspring,
Aef f= π 4 d 2 w As shown into the Fig.1,7 the variable def f represents the effective diameter.
Figure 1.7: Effective surface of the airspring[21]
Since the airsprings are flexible structures, in many cases the effective surface area Aef f is not constant over the entire spring travel. This variation is mostly depending on the design principle and the type of the airspring. The following Fig.1,8 to Fig.1,10 show the characteristic lines of the change in inner volume (Vi), inner pressure (Pi) and the applied load (F) with airspring cyclic movement. The influence of the airspring move can be clearly seen on these