• 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…
  • SACS - Strange SCF of Tubular Connection with Ring Stiffeners

    Dear Sir, I am curious about SCF calculation for tubular connection with ring stiffeners. It is mentioned that Smedley and Fisher (1991) formula is applied. The R-factor calculated by using the formula mentioned above looks ok. However, the final…
  • Effective thickness of Grouted Joint in Fatigue Analysis

    Dear Sir, I'm running a spectral fatigue analysis for a platform with grouted legs. These are my section input for my joint cans at leg SECT LEGCAN TUB 111.765.08091.4403.810 SECT LEGCAN1 TUB 111.765.50091.4403.810 SECT LEGCAN2 TUB 111.766.00091…
  • Fatigue analysis

    In fatigue analysis should we consider gravity loads viz equipment loads, piping loads etc in SACS model while running it for seperate sea state.
  • joint flexibility option in fatigue analysis

    When do we consider the joint flexibility option in fatigue analysis. I am doing deterministic fatigue analysis. Need to know when joint flexibility needs to be considered. What is the basic difference when the joint flexibility kept on and off. Th…
  • RE: Error while running spectral fatigue analysis

    Irfan, Are you using multiple common solution files which are dissimilar? It appears that SACS is looking for members that don't exist in your common solution file. If you would like, you can submit a service request and attach the files so that a…
  • Error while running spectral fatigue analysis

    I am getting following error while running "post-processing" spectral fatigue analysis: "*** ERROR - MEMBER 2264-2265 NOT IN ORDER ON 8 POSTFILE IT SHOULD PRECEDE - MEMBER 6842-6843 *** ERROR - MEMBER 9546-9547 NOT IN ORDER ON 8 POSTFILE IT…
  • Fatigue Analysis Force-Time history

    Hi, I try to conduct fatigue analysis by using SACS. With very useful answer in the communities, fatigue analysis was successful. However, I also want to conduct a fatigue experiment for some members based on results from fatigue analysis by SACS…
  • RE: Can we use load RAOs to generate common solution file with inertia loads for fatigue analysis. If yes, how it can be done?

    Anupam, Let's first look at the input requirements for a tow fatigue analysis: Fatigue Input File (ftginp) Common Solution File (saccsf) Seastate Input File or Tow Input File (towinp) The fatigue input file defines the fatigue cases which…
  • RE: USER DEFINED SCF FOR TUBULAR CONNECTION

    C.karthikeyan, You can specify SCF overrides in a variety of ways in your fatigue input file, the most common being the SCF line and the CONSWF for plate girders. The SCF line can be used to override SCF's for all plate girder connections whereas the…
  • RE: How to perform spectral fatigue analysis using SACS

    Stephen, You need to do a Tow Fatigue analysis. Tow Fatigue will analyze fatigue damage of a structure by generating transfer functions using motion RAO's (Velocity, Motion or Acceleration RAO's) and combining those transfer functions with the wave…
  • RE: Wave spreading application

    Sanjay, That is not how the wave spreading works in SACS. When you select the wave spreading option, SACS will take the load cases from +- 90 degrees from the fatigue load case direction and factor those load cases using cos^n(theta) so that total equivalent…
  • Fatigue - Time history

    Hi, May I know that SACS is able to carry out fatigue time history analysis ? I try ti do it but I was not successful. A wave response analysis is carried out to create force time history and use it to fatigue calculation, but it has an error. I wondering…
  • RE: SACS - Morison Drag Linearisation for Frequency Domain Analysis

    Kasiphon, The nonlinear drag component in spectral wave fatigue analyses is addressed by using constant steepness waves when generating transfer functions. See Section 16.7.2.3 of ISO 19902. Regards, Geoff
  • RE: SACS Broad-Band Random Process

    Kasiphon, The broad band option in SACS utilizes the equations presented in Application of computers in fatigue analysis ( Dirlik 1985). Dirlik uses an empirical formula to calculate the rainflow range density for various sea-states including double…
  • RE: SACS - how to display fatigue lives via labelling in v10.1

    Sam, I would definitely rerun the fatigue analysis in the new version if you are using the fatigue extract file with the new viewer. I believe there is some additional information that is saved to the fatigue extract file which may cause errors in Precede…
  • RE: SACS - how to display fatigue lives via labelling in v10.1

    Hi Sam, There is a way to show all joint fatigue details within post view. To do this you have to make sure that you have a post view database after your analysis. Then when doing your fatigue analysis you then need to add 'Fatigue Extract File Option…
  • RE: Thickness Reference (tref) in SACS Built-in S-N Curve

    Kasiphon, When selecting the NT option for the Norsok 'T' SN curve, SACS actually uses the 3.2 cm minimum thickness instead of the 2.5 cm minimum output (See below). There is currently no way to override the minimum thickness used for thickness correction…
  • Thickness Reference (tref) in SACS Built-in S-N Curve

    Dear Sir, Do we have any command to change thickness reference in built-in S-N curve in SACS? For example, Thickness reference for tubular connection should be 32mm for DNVGL-RP-0005 (2014) S-N "T" Curve. However, SACS used tref = 25mm for…
  • RE: DNVGL-RP-0005 (2014) : Reduction factor for root stress of single-sided welded in tubular joints

    Kasiphon, The DNV reduction factors for single sided welds were added to SACS 10.0. Use 'ERD' in columns 78-80 on the FTOPT line to select this option. See the SACS 10.0 Connect Edition Release Notes for more information. Regards, Geoff
  • RE: foundation superelements for various purposes

    The pair of forces are for the X and Y components of the pilehead stiffness as they are calculated independently. Refer to section 2.5.1 of the PSI manual. You want to linearize the piles using the loading that will be closest to the actual loading…
  • RE: Fatigue analysis process

    1. You only need the scatter diagram data for the fatigue input file which is based upon the environment. There is no iterative process since the environment is not dependent upon your structure. 2. The fraction of design life is the ratio of the time…
  • RE: A couple of questions

    In the case of tow fatigue, the naval architect would typically provide the structural engineer with response amplitude operators (RAO's) which are calculated using their hydrodynamic analysis in MOSES. The structural engineer would then calculate the…
  • RE: Combining Fatigue Damages

    You can combine multiple fatigue analyses by generating fatigue damage files. On the first fatigue analysis, select the "output fatigue damage file" option in column 76 on the FTOPT2 line in the fatigue input (ftginp) file. A fatigue damage (ftgdmg…
  • RE: User Defined SCF Values in SACS

    Kapildeb, I apologize for the confusion. It appears that the CONSCF card image was generated incorrectly for the manual and needs to be fixed. I have attached an older version of the same card image with the correct input for that table and I have submitted…