Unidirectional loading

Figure 1. Development of the finite-element mesh for the cylindrical-material model, showing the shape of the deformed grid for application of unidirectional load (---). The interface on the grid is indicated by the arrows.

Under unidirectional loading, the shape of the deformed sphere of isotropic material is an ellipsoid. This deformed shape must also be attained by a cell of rubber-toughened epoxy because the overall material is isotropic. This shape would not be attained from application of the load alone constraints... 

As just described, the deformed shape of the rubber sphere surrounded by an annulus of epoxy must be a perfect ellipsoid because the overall material is isotropic. As shown by equations 1 and 2, the deformed shape BC is defined from the Poisson ratio, and Youngs modulus can be calculated from summing the reactions. However, for the toughened material, the value of the Poisson ratio is not known only a relationship between E and v is known, as defined by K. Thus, the analysis of unidirectional loading for the spherical cell must be carried out using an iterative procedure. The method has been described in detail elsewhere (15). The results of the iteration can be verified by checking the reduction of the x reactions-to-earth to zero this verification was used for all the results presented here. 

When idl B ID, then (id-2ul) = -id and in fig. 3c, the rotor speed is id in the clockwise direction. The eccentricity ratio and attitude angle for the synchronous rotating load are therefore the same as for a bearing subject to the same unidirectional load. The load vector lags behind the line of centres in fig. lb, while for the synchronous rotating load, the load vector leads the line of centres, fig. 3a. 

Using the previous calibration of the analytical model by means of bidirectional loading tests, the restoring forces and those calculated by the model under unidirectional loading are compared in Fig. 4 for a medium-size rubber bearing. The test results were conducted for a maximum average shear strain of 150 %. 

Consider a transverse loading of unidirectional loading composite as follows ... 

---