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Calculation method of elastic modulus:
1 in the elastic range of materials to determine the initial elastic section of a straight line, with the correlation coefficient r to evalsuate the good or bad;
2 using the least square method to fit the slope E (initial elastic modulus);
3 the coefficient V of the fitting slope is calculated, and its value is within 2%, and the young's modulus is valid.
In the data processing, the initial segment of the tensile testing machine software stress strain curve is very similar to the range of a straight line. The general determination of the material's non proportional extension strength as the upper limit, the correlation coefficient, elastic modulus, the coefficient of variation. If the results can not meet the standard requirements, then the point from the point of change to calculate the point to calculate the R, until r close to 1, determine the corresponding arc section for the calculation of elastic modulus. In the tensile testing machine, it is to collect enough points from the range, to ensure that the slope of the fitting coefficient of variation V in 2%.