USING FINITE ELEMENT ANALYSIS AND STRAIN GAUGE EXPERIMENTAL DATA TO EVALUATE STRESS CONCENTRATION FACTOR ON PRESS-FIT ASSEMBLY

The behavior of any physical structure is usually non linear. However, the response of a given structure can often be approximated to a linear case if its deformations or local displacements are small. This simplification is even more acceptable when the assembled parts are able to interfere each other, a good example of interference fit is a shaft assembled inside its housing. Interference fit tools can be used to better understanding of joint parts mounted in circular geometry. Analytically is possible to have an initial approach in determining the amount of efforts applied to a giving joint system. Almost all machine components and structural members suffer some form of geometrical recoil due to backlashes and production tolerances, or, in some cases, one can experience abrupt change in cross section or internal micro structural discontinuities. Those factors, associated with the local stress are coming from Press-fit process causing pre-tension on internal and external surfaces. The maximum local stress normally occurs at these discontinuities and local defects. The nominal stress can be calculated, for a particular loading and net cross section, assuming a stress distribution for a uniform geometry. This paper presents the analytical treatment of the stress concentration factor, based on the elasticity theory, in association with finite element analysis and the experimental data from a strain gauge. That system was able to measure small deformation from assembled parts and its correlations.