Experimental Investigations on Tension and Compression Properties of an Electro-Rheological Material

This work is concerned with experimental investigation on properties of an electrorheological fluid subjected to static and dynamic tensile and compression loading. The electric voltage is kept constant during the tests and the initial electric field strength ranging from 0.5-5 kV/mm is generated to observe its influence on the stress-strain curves in compression and tension. Glass fibre is also added to investigate its effect on strength of the ER fluid. In addition, strain rates of 0.5 mm/min and 1 mm/min are imposed to investigate behaviors of ER fluid under the dynamic tensile loading condition. Experimental results from this work reveal that the yield strength in tension and peak stress level in compression are an order of magnitude higher than those in shear. The results also show that the yield stress and Young's modulus of the ER fluid in the absence of the fiber increase with electric field strength in the tensile test with a dynamic load. Beyond the yield point in a tensile test with the fiber, the stress is maintained at a significantly high level over a large range of strain, which indicates a high toughness of the ER fluid in tension. Addition of the fiber content also helps to increase significantly the yield stress and tensile strength. In addition, with addition of the fiber to the ER fluid, the Young's modulus becomes insensitive to electric field.