How to plot log displacement versus log frequency curve in abaqus while post processing the random vibration analysis resultsand also PSD vs Frequency plot.
In the visualization module, go to create XY data > Operate on XY data. Then on the left side you will find several operators. You can use those operator to calculate required data and save it. If the required operations are not listed there, you can simply copy the data to excel sheet and process it there or in any other software (like matlab etc.)