Determination of the Value of E in Metallic Materials

"In the structural analysis of mechanical elements, both in the design and testing phase, the Young’s modulus value influences the precision of the results and must be taken into consideration during the calculation. . The E value is usually shown in tables that do not report precise values, but ranges of values that are characterized by a certain amplitude.. In the structural calculation analytically or numerically developed, an approximate reference E value that is hypothesized constant in the material is usually used. Moreover, this value does not take into consideration possible thermal-chemical-mechanical treatments used on the material. . A mechanical designer needs to know the precise E value of the material in the final operation state in order to develop a structural analysis.. According to what has been specified above, it is necessary to know the value of the elastic characteristics for every point of material in order to associate a value in the development of a correct and deepened numerical analysis for every zone in examination. . We have developed a finely tuned experimental system having the following main steps:. -\tmeasurement of the penetration of a metallic microsphere, as a function of the applied load, in a single point of the analyzed material;. -\tdetermination of Young's modulus.. This procedure allows for E to be measured, if necessary, at points very close to each other in such a way as to be able to take into consideration, when performing structural analysis requiring a high degree of accuracy, the influence of the gradient of the longitudinal elastic modulus.. The precision of the punctual values obtained for E is comparable with that of traditional experimental methodologies (e.g. tensile test), since the proposed procedure expects the use of the experimental calibration curve, which is precisely constructed based upon the data obtained through the above methodologies.. "