Strength and Impact Concerns for Performance

Part yield strength. The part is loaded beyond the normal functioning range of loads and the onset of permanent deformation beyond a certain point determines the strength of the part. This deformation can cause the part to stop functioning. 

Part stiffness. When a part is loaded, the amount of deflection that occurs is considered to be the strength of the part. The ratio of load to deflection is actually the stiffness of the part rather than the strength of the part. 

Strain-controlled applications. In these applications, a definite strain is applied. The failure mode for the part may be fracture from exceeding the maximum elongation for the material, permanent deformation from exceeding the yield point, or fracture over time from strain close to the maximum elongation and subsequent creep rupture. 

Part ultimate deflection. The maximum deflection of an application is dependent upon the percent strain to failure of the material, part geometry, loading, and constraint. 

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