Retrieval of Fatigue Load Histogram or Numbers/cycle and Stress Range Raw data for external design

Dear Sir,

Could I know is it possible for me to extract fatigue load histogram in specific joint in SACS? If the histogram is not availble, is it possible for me to get the raw data (numbers/cycle and stress range) in listing file/postvue so that I can create the histogram myself?


I need this since there is a special swaging design that we need to send the data to vendor for their design on the swaging connection..

Thanks,
Pei Shing

  • Pei,

    You can generate a stress vs cycle report from a time history analysis using Interactive Fatigue.

    Open the fatigue extract file for the joint in Interactive Fatigue, select File -> Generate Report, select Report Type: Fatigue Stress vs. Cycles and enter the joint and load case information, then click Apply to generate the report. You should see a report with a list of stress ranges and cycles for that joint.

    Regards,

    Geoff

  • Hi Geoff,

    Thanks. However, there is a problem with latest SACS 11.0.0.1 version. I couldn't open the ftgext file.

    Thanks,

    Pei Shing

  • Hi,

    I already downloaded and installed SACS 11.1. However, for Fatigue Stress v. Cycles, once I click apply on any joint, the whole interactive fatigue will be disappear (shut down itself) instead of generate data for me. 

    I even tried with sample \Demo05b, by only added EXTRACT HEAD AE.9E-9 in ftginp.demo05b, and try with this. Same thing happened, the interative fatigue shut down automatically after I clicked apply button or OK buttion.

    Thanks,

    Pei Shing

  • Pei Shing,

    My apologies, I was running a test build where this has been fixed. Apparently it isn't working in 11.1 or earlier. I am sorry for the confusion.

    There is another way to generate stress vs. cycle tables using the ST-CYL command in you fatigue input file.

    Here is a copy of the Demo05b fatigue input file with the ST-CYL line added.

     FATGIUE DEMO 5b                                                                                                       
    FTOPT  20.    1.0    2.       SMAPP        SK                              LPEFT                                       
    FTOPT2     PTVC                                   AWS              TI                                                  
    JNTSEL RM SM     501  503  505  507  801  803  805  807                                                                
    JNTOVR  401 API                                                                                                        
    JNTOVR  403 API                                                                                                        
    JNTOVR  405 API                                                                                                        
    JNTOVR  407 API                                                                                                        
    GRPSEL RM      PL1 PL2 PL3 PL4 W.B                                                                                     
    SCFSEL                 MSH                   
    ST-CYL   60    25.   0.25                                                                                              
    RELIEF                                                                                                                 
    SEAS                                                                                                                   
    FTCASE   1 1.0      1.0        SPC                                                                                     
    SCATD D 1.0   1.0              PM                                                                                      
    SCWAV       1.0   3.0   6.0                                                                                            
    SCPER 1.5   .15   .1    .1                                                                                             
    SCPER 3.0   .1    .19   .11                                                                                            
    SCPER 5.0   .05   .08   .05                                                                                            
    SCPER 8.0   .02   .03   .02 
    EXTRACT HEAD AL                                                                                                        
    END       

    An additional output file (ftgmsg.demo05b) will be generate which contains the 60 divisions starting at 25. ksi and with 0.25 ksi increments, for each joint and each location.

    Regards,

    Geoff