A Method of Structural Analysis for Small Items in a Random Vibration Environment, Part II

To perform engineering analyses in the most cost-effective manner, engineers must eliminate non-critical design items from a detailed analysis program and concentrate on the marginal and critical design items. This paper shows an approach to accomplishing this objective through the use of a rapid single-degree-of-freedom analysis. Part I develops equations for determining dynamic stresses on structural items modeled as simple beams and presents a non-dimensional method for determining the equivalent spring rate of a variable-stiffness beam. Part II presents a step-by-step example that provides the deflection, equivalent stiffness, frequency and dynamic stress on two different beam configurations with their predicted times-to-failure. In addition, the deflection and frequency results from a finite-elementmodel analysis of two tapered brackets are compared with the results from the non-dimensional variable-stiffness beam method developed previously.