Learning Forum

[Jeone]

Hi,

I have loads varying between 1N and 10N. (There are also loads like 9.2N and 8.3N, so they are not evenly spaced.) For example, after performing the analysis at 1N, I will need to multiply the fatigue analysis result for 8.7N by 8.7, which causes a loss of nonlinear effects. Instead, I want to perform separate analyses at 9N and 8N and then use the stress result from the 9N analysis for the 8.7N result, or use the 8N analysis for the result at 8.4N. In summary, I want to proceed using interpolation in nCode DesignLife. Is it possible? 

I hope, I was able to express myself clearly

[danielshaw]

I am sorry, but I do not understand your question.  Ansys nCode DesignLife uses the FE results (typically from Mechanical).  It can scale those results using Constant Amplitude or Time Series loading, or with scale factors for any load provider.  It is not clear what you mean by "using interpolation in nCode DesignLife".

[Jeone]

Before the fatigue analysis, I will do static analysis with 1 N unit load, however as you see, there is 9.6N in the loads. nCode will multiply 9.6 with 1N stress result, so nonlineer situation will not effect. In this way, I want to do 1N, 2N, 3N...9N static analysis. I want nCode to do the following. Take the 9.6N load from the 9N static analysis or use the result of 10N if it is closer to it. Like interpolation. I hope, I could tell it.

[danielshaw]

I do not believe that Ansys nCode DesignLife can do what you desire.  With a TimeSeries load provider, DesignLife will multiply the results from the file.rst (for whatever loading was used to create that file.rst) by the values in the TimeSeries input file to obtain the total stress to be used in the fatigue evaluation.  So for the image that you show, DesignLife take one FE result set and create 11 result sets for the fatigue evaluation.  It will rainflow those results to obtain the critical stress ranges and mean stresses to be used in the fatigue evaluation.  With the TimeSeries load provider, DesignLife cannot select a subset of results or interpolate results.  If you want to use a subset of result sets in the fatigue evaluation, you need to calculate FE results for those specific loadings and then use a TimeStep load provider to identify the specific result sets for DesignLife to use.