5.9 Viewing Results

There are a few ways to view the results. The following is an example of the results. Depending on the type of analysis, the items in the report and charts may vary.

5.9.1 Report

Depending on report type specified in Project Setup, the report can be as simple as a summary, or as regular report, or as detailed report. In this tutorial, we selected Summary option. To view the report, choose Report>Open result report, or click Open result report button . The result report file opens:

The summary at the bottom of the report shows the maximum fatigue damage ratio and fatigue life. The fatigue life refers to repeats of block. The block is the block of stress values that is entered in the loading input and that is shown on the charts. A block can consist of a number of cycles (e.g. -20, 10, -30, 50, -10, 30, -40, 40, -20), or it can be a single cycle (e.g. 0,50,0); it can even be half of cycle (e.g. 0,50). In the single cycle case, the "repeats of block" equals to allowable number of cycles. Node number indicates the node where the maximum damage takes place. Surface refers to surface of shell elements; first (1) surface is bottom shell surface, second (2) surface is top, and the third (3) is the middle surface. For other elements the surface is always 1. For manually inputted data, ignore node number and surface.

5.9.2 Stress & Temperature Time History Chart

Choose Charts>Time History or click Time History button . The Stress & Temperature Time History chart appears. The following chart is an example. The items in the chart vary for different models.

Uncheck Nominal principal stress and Nodal Temperature check boxes. Choose Critical Plane Angle X, Critical Plane Angle Y, Critical Plane Angle Z check boxes, the chart displays the angel between the normal of the critical plane and X, Y, Z axises. The colors, widths and dash type of the curves and background can be changed by clicking Styles button.

5.9.3 Stress Range Histogram Chart

Choose Charts>Histogram or click Histogram button . The Stress Range Histogram chart appears. The chart shows cycle counts for each stress range band. The stress range bands are grouped by the program using rainflow counting algorithm. The grouping is for reporting purpose and does not affect fatigue life analysis accuracy. The histogram is an approximate representation of the distribution of stress ranges. The entire range of values is divided by the number of bins into a series of intervals. The program counts how many values fall into each interval. The vertical bars represent the frequency, that is, the number of cycles in each bin. Some bins can be empty.

5.9.4 Damage Ratio Chart

Choose Charts>Damage Ratio or click Damage Ratio button . The Fatigue Damage Ratio chart appears. The chart shows damage ratios for each stress range band and cumulative damage ratios for all stress range bands. The grouping of the stress range bands is arbitrary by the number of bins for statistical result reporting purpose. The actual fatigue life is assessed on each time step, not the bands. The damage ratio line in the chart represents damage ratio by each stress range bin. Each dot represents a bin value. The cumulative damage ratio line in the chart represents successive additions of damage ratios created by individual stress ranges in the bins. The last point to the very right represents the total damage ratio.

The charts can be zoomed, printed, or exported by clicking on correspondent buttons. The styles of the chart can be edited by clicking Styles button.