[Mohanraj, 3(6): June, 2014] ISSN: 2277-9655 Scientific Journal Impact Factor: 3.449 (ISRA), Impact Factor: 1.852 http: // www.ijesrt.com(C)International Journal of Engineering Sciences & Research Technology [518-521] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY Development of Flexible Bearing K.S.Mohanraj AP, MECH Dept, Professional Group of Institutions, Tiruppur, Tamilnadu, India ksmohanmit@gmail.com Abstract Elastomeric base isolation systems are proven to be effective in reducing seismic forces transmitted to buildings. However, due to their cost, the use of these devices is currently limited to large and expensive buildings. A fiber reinforced elastomeric isolator utilizes fiber fabric, such as carbon fiber, glass fibre, and etc. as the reinforcement material instead of solid steel plates. The fibre fabric reinforcement is extensible in tension and has no flexural rigidity. Elastomers normally used in the isolator are natural rubber; neoprene, butyl rubber and nit rile rubber etc. These devices were fabricated by binding alternating layers of rubber and fibre mesh. The fibre mesh is used to increase the vertical stiffness of the bearings while maintaining low lateral stiffness. Characterizing the behaviour of a fibre reinforced bearing “shape factor” of the bearing, Poisson’s ratio of the elastomeric material and flexibility of the reinforcing sheets and investigate the effect of reinforcement flexibility on compressive behaviour of elastomeric bearings with different geometrical and material properties. Bonding with fibre reinforcements can increase the stiffness of elastic layers only when the elastic layer is compressed. Keywords: SRBI (Steel reinforced base isolator), FRBI (Fibre reinforced base isolator), NR (Poly isoprene), Reinforcements.. Introductions Elastomeric bearings are finding ever increasing application in today’s construction industry. Although used extensively in Bridges, bearing pads are being specified in a wide variety of applications where flexible structural support and/ or vibration isolation is required. The typical application range is from concrete buildings and parking garages to heavy industrial equipment, storage tanks and pipe supports. Their popularity is understandable in view of the following advantages Performs required functions efficiently Totally maintenance free No moving parts and therefore no wear & tear No corrosion Absorbs shocks & vibrations Cheaper than mechanical bearings Simple to install Capable to accommodate small irregularities in the loading surface. A. Function of a base isolator A base isolated bearing must perform the following basic functions Support vertical loads with a minimum of deflection. Allow horizontal movement with minimal resistance thereby reducing detrimental Effects of creep, shrinkage and temperature change. Allow rotational movement with minimum resistance. Obtain uniform distribution of loads. B. Elastomers Elastomeric Bearings have no moving parts to perform their required functions. Instead, they achieve this through deformation of the Elastomers. Obviously then, the properties of the Elastomers largely determine the behaviour of the bearing. Although a wide variety of Elastomers are available, only two types are allowed in base isolated bearings (I) Natural Rubber (ii) Neoprene C. Natural rubber Natural rubber is an elastomeric material which is used as Low frequency anti vibration mountings Structural bearings. So that it should have the following properties Very high resilience , low damping for maximum vibration isolation efficiency , very low creep and low chemical and oil resistance D. Reinforcements Enforcing a material into another material will produce new kind of structure with enhanced properties of primary material. In flexible bearings steel and fibber used as the reinforcements which will stiffen the its structure when it is subjected loading E. Steel Bonding of sheets of rubber to thin steel reinforcing plates to produce a composite with very