3. For the block of strain history given below acting at a critical point in a medium strength steel (or' = 175 ksi, b = -0.085, &' = 0.8, c = -0.6, E = 30. x 103 ksi, K' = 181 ksi, n' = 0.14): (a) Obtain a cycle count of the strain history using the rainflow counting method. (b) Plot the stress-strain response over the entire strain history. A hand drawing of plot is fine but please try to draw as accurately as possible consistent with your calculations using the monotonic/cyclic Ramberg-Osgood equations. (c) Perform a strain-life analysis using the Palmgren-Miner linear damage rule. Use the Manson and Halford modification to the strain-life equation to account for mean stress effects. (d) What percentage of damage does each cycle contribute to the block loading? What does this suggest regarding the effects of very small subcycles on the overall life of a variable amplitude loading history?/nStrain (%) 96 0.6 0.5 0.4- 0.3 0.2 0.1 ° -0.1 -0.2H -0.3 -0.4 -0.5 -0.6 M Time

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