EM-304.02 | Linear Modulus of Rigidity Apparatus

This experimental unit enables the relationship between shear loading and shear deformation to be determined using simple experiments. A rubber block between two flat pieces of steel is used as the shear body. One steel plate is fixed to the base plate with bolts, a force can be applied to the other by attaching weights to a hook. A dial gauge fitted to the bracket records the deformation that occurs. The unit is fitted to the wall using bolts. It is suitable both for laboratory experiments and for demonstrations. Rubber blocks in shear force are often used on engines and in equipment mounting to isolate vibrations. They do this by absorbing shock energy by deforming. This deformation leads to a decrease in cross-section as the block lengthens, an effect described by Poisson’s Ratio. After this experiment, students will understand the behavior of a very flexible material such as rubber. Rubber is interesting in that the lay person regards it as an elastic material. In engineering terms, it is not as elastic as steel and often exhibits a high degree of hysteresis. A rubber block 195x100x25mm is bonded to two aluminum alloy plates. One plate is screwed to a wall, whilst the other has a shear load applied by a loaded weight hanger. A dial gauge measures the deflection of the block.