Define Recommendations for confined elastomeric pad?

 (a) Permissible limits for confined pressure on elastomer pad depends upon effectiveness of internal seal preventing it from extruding. Therefore, it shall be verified by load testing of assembled bearing.

Figure: Deflection in Elastomeric Pressure Pad

(b) Dimensioning of pad should be such that at design rotation, the deflection at perimeter shall not exceed 15% of pad thickness (he,eff) below internal seal.

(c) Even then average stress in pad shall not exceed 35 MPa and extreme fibre stress shall not exceed 40 MPa. However minimum value, under any critical combination of loads, shall not be less than 5 MPa.

(d) The thickness of confined elastomeric pad shall not be less than 1/5^th of its diameter or 16 mm whichever is higher. Its diameter shall not be less than 180 mm.