The Significance of Equi-Biaxial Bubble Inflation in Determining Elastomeric Fatigue Properties

Fatigue life prediction of magnetorheological elastomers subjected to dynamic equi-biaxial cyclic loading

“…Previous research into fatigue of non strain-crystallising elastomers (ethylene propylene diene monomer, EPDM and styrene-butadiene rubber, SBR) by Abraham [20,21] and Alshuth et al [22] suggested that when subjected to uniaxial loading these materials exhibited a limiting value of complex tensile modulus (E*) and this value could be used effectively to design against fatigue failure in rubber components. The concept of using a limiting value of E* was further supported by the research of Jerrams et al [23,24] and Hanley et al [25,26] for EPDM samples, both swollen and unswollen, subjected to equi-biaxial stress cycles.…”

“…The system comprises controlled deformation cycles using a hydraulic inflation medium with a vision system and simultaneous data recording. The theory for obtaining stress-strain relations at the bubble pole which underpins the testing system is described elsewhere [15]. The engineering stress (σEng) and the principal stretch ratio can be obtained using the following equations [16]:…”

Improving the electromechanical performance of dielectric elastomers using silicone rubber and dopamine coated barium titanate

“…The bubble inflation test system [41,42] was designed for the equibiaxial mechanical testing of elastomers by means of hydraulically inflating test samples using silicone oil (Fig. 2).…”

The fabrication of dielectric elastomers from silicone rubber and barium titanate: employing equi-biaxial pre-stretch to achieve large deformations

“…However, most research into the mechanical properties of DEs was carried out using the conventional uniaxial tensile test [29,11]. In this work, initially a static mechanical equi-biaxial test was applied using a bubble inflation test system [30,31]. DEs with SR and BT were fabricated and subjected to equi-biaxial pre-stretch in order to obtain a large voltage-induced deformation under a relatively low electric field.…”