• Wave Response Member Force Transfer Functions

    Geoff McDonald
    Geoff McDonald
    Introduction You may have tried to validate stress transfer functions calculated in Fatigue against member end force transfer functions generated in Wave Response and found that the transfer functions do not match. In this post, we will take a look…
    • over 1 year ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower - Wiki
  • SACS - Wave loading on plate elements

    Adel Hesari
    Adel Hesari
    Good day, I have noticed that wave loads generated in SACS are not applied to plates elements. To be more specific, I am modelling a caisson using plate elements. After applying the environmental information to generate and apply wave loading, it…
    • over 1 year ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • P-delta effects in wave response analysis

    Shabad Valiyarambath
    Shabad Valiyarambath
    Hi, Does the SACS wave response module able to consider the pdelta effects (using PD commands) when generating Base shear transfer function AND also when generating the equivalent static load for accurate stress recovery.
    • over 2 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • SACS / spectral fatigue analysis

    Mohamed Mahmoud
    Mohamed Mahmoud
    hi all , while generating the seastates (dynamic transfer function) on a cantilever inside the water it was noticed that there is bulb at the early frequency. any ideas why this happens and thanks
    • over 3 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • Tow Fatigue with SACS

    Василий Сивовол
    Василий Сивовол
    Hi there. I need to perform Fatigue analysis for sea transportation in order to understand this calculation I started studying this guide "Tow Fatigue with SACS". I ran into a problem, if I understood correctly this formulas => have to calculate these…
    • Answered
    • over 3 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • DAF random wave for jack up

    Xiang Li
    Xiang Li
    Dear friends I am following the SNAME method to estimate the DAF for jack up, based on 3 hours time domain random wave analysis. As per SNAME, the DAF from overturning moment (OTM) should be higher than the DAF from base shear (BS). However, the 2…
    • over 4 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • DAF Computation - Wave-Current Interaction - SACS - Dynamic Wave Response Analysis

    Swarup Selvaraj
    Swarup Selvaraj
    Dear All, I understand that only waves cause dynamic effect on offshore jackets and current does not contribute in the dynamic behaviour. I have the following questions regarding to computation of DAF: 1. Is it correct to compute the base shear…
    • over 4 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • Deep Water Jackets (Water depth > 200m), Dynamic Amplification Factor Computation

    Swarup Selvaraj
    Swarup Selvaraj
    Dear all, Which would be the best method to compute the Dynamic Amplification Factor (DAF) for dynamically sensitive jackets (water depth > 200m) Method 1: Using equivalent static loads in wave response input file, without using any wave spectrum…
    • Answered
    • over 4 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • Selecting modes with mode number higher than 100 for steady state deterministic wave analysis

    Eduard Hendriksen
    Eduard Hendriksen
    Good day, I am trying to determine the steady state response of a large model loaded by waves and current. Due to the size of the structure and the number of dofs to be considered for dynamic analysis, the number of structural eigenmodes is far…
    • over 5 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • Extrapolated and Stretched Airy Wave Theory

    Kasiphon Kurojjanawong
    Kasiphon Kurojjanawong
    Dear Sir I am curious about Airy wave theory using in SACS. Refer to 'Seastate manual', AIRY in WAVE card means that kinematic will be calculated at wave crest and trough. AIRC in WAVE card means that kinematic will be calculated at water line…
    • Answered
    • over 6 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Wave response Program

    Geoff McDonald
    Geoff McDonald
    1) The stiffness of the structure does not change. 2) The equivalent static load will include dynamic response of the structure. 3) The soil stiffness is non-linear and is dependent upon the load on the piles. The load used to linearize the piles…
    • over 6 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Dynamic Super Element Analysis

    Geoff McDonald
    Geoff McDonald
    Amit, It seems odd that the dynamic superelement data file would be the issue since you are able to run Dynpac without any error. The problem may be with your wave response input. For some reason I can't see the images that you posted so I can't tell…
    • over 6 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Wave spreading application

    Geoff McDonald
    Geoff McDonald
    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…
    • over 6 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: SACS - Morison Drag Linearisation for Frequency Domain Analysis

    Geoff McDonald
    Geoff McDonald
    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
    • over 6 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Spectral Fatigue Analysis

    Geoff McDonald
    Geoff McDonald
    Quoc, It is possible that the "Use Wave Response Input File" option is set to "No" in your Dynamic Wave Options. Make sure this option is set to "Yes". I would recommend trying to recreate the analysis from scratch to ensure that the runfile options…
    • over 7 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Spectral Fatigue Analysis

    Geoff McDonald
    Geoff McDonald
    Quoc, Sometimes analysis options may be available only when certain input is in your input files. It is possible that you are missing some critical input in the wave response input file. Unfortunately, it is difficult to say without looking at your…
    • over 7 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Wheeler Stretching

    Geoff McDonald
    Geoff McDonald
    Kasiphon, 1. The 'WH' option is the Wheeler stretching option for random wave analyses. The wave kinematics are calculated for the wave at the water line elevation using the Airy wave exponential decay and then that curve is stretched or compressed…
    • over 7 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: Spectral Fatigue Analysis

    Geoff McDonald
    Geoff McDonald
    Nalinii, General Wave Response and Deterministic/Transfer Function Generation are both part of the Wave Response module so they are very similar in execution. In fact, the only difference between the two is the input that you provide in you wave response…
    • over 7 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum
  • RE: New Wave Theory by Tromans (1991)

    Geoff McDonald
    Geoff McDonald
    Kasiphon, The supported wave theories in SACS are listed in section 4.3 of the Seastate Manual and the New Wave theory is not listed in the list of included theories. I have included the list of supported wave theories below: 1. ‘AIRY’ Airy (or linear…
    • over 7 years ago
    • MAXSURF | MOSES | SACS | OpenWindPower
    • MAXSURF | MOSES | SACS | OpenWindPower Forum