To determine the nominal or engineering stress and strain experienced by a specimen of a material while it is subjected to a tension test, and to be able to read important values from a conventional stress-strain diagram obtained from the test.
A tension test is being conducted on a steel-rod specimen with a gauge length of L0=50 mm and initial diameter of d0=13 mm. Data were collected to form the conventional stress-strain diagram as shown. From the diagram, f = 510 MPa , e = 701 MPa , g = 585 MPa , and h = 0.154 mm/mm .
Part A - Nominal or engineering strain in the rod
Assuming that the strain remains constant throughout the region between the gauge points, determine the nominal strain ε experienced by the rod if it is elongated to L = 65.0 mm .
Part B - Nominal or engineering stress in the specimen
Assuming that the stress is constant over the cross-sectional area and if the tension force used is P = 14.0 kN , find the nominal stress experienced by the rod.
Part C - Force needed to reach the ultimate stress
Determine the force P needed to reach the ultimate stress in the steel-rod specimen.