1. 1 The Code Optimisation Module - PROCODE Rolf Skjong & Knut Ronold Det Norske Veritas Rolf.Skjong@dnv.com JCSS Workshop on Code Calibration, March 21-22 2002

2. 2 PROCODE PROCODE was developed in the early nineties in the Reliability of Marine Structures Project.. first use published at OMAE 1992 …code optimisation.. has been used extensively in many code calibration studies on ship rules.. has been used on a project basis on other calibration studies (e.g. Danish Wind Mill design code).. is linked to PROBAN.. use PROBAN for all reliability calculations

3. 3 PROCODE Objective –Optimisation of partial safety factors –Control Variables: Partial Safety Factors –Minimum Scatter around a target reliability by minimising the penalty function

4. 4 PROCODE SCOPE of code is specified by design cases External and Internal Conditions are specified separately External: –External could be environmental conditions (H s,T z ) –Conditions are associated with a Name-Set –PROCODE take care of the Name-Set and Names that points to the PROBAN variables during execution

5. 5 PROCODE Internal: –Relates to structural conditions –Internal could be such as material properties, slenderness measures –Conditions are associated with a Name-Set –PROCODE take care of the Name-Set and Names that points to the PROBAN variables during execution

6. 6 PROCODE The scope is defined by the design cases defined by combining external and internal conditions

7. 7 PROCODE Variables –X, stochastic –E, environment –D, design situation –, design parameters that may be chosen by the designer

8. 8 PROCODE Limit State Function: G(X,E,D, )>0 Code Check Function: h(x,e,d,, )>= 0 M failure modes k=1-M N k code check functions n=1- N k Code check requirements: h nk (x, ei,d i, ij, ) >= 0 Limit State functions: G k (X,E i,D i, ij ) >= 0 i,j defining the scope matrix

9. 9 PROCODE Subjected to : With one of the inequalities turning into equality One design Case : This is generalised to Multiple design cases in PROCODE

10. 10 PROCODE Programmable functions –Limit States –Code Checks –Penalty functions Defined by Data (additional to PROBAN) –Scope (Internal, Internal) –Safety Factor –Design Parameter

11. 11 PROCODE RESULTS Code Evaluation (before optimisation starts) Optimised partial safety factors Resulting reliabilities Resulting design parameters (input to cost analysis)

12. 12 PROCODE Examples Jack-up, spudcan/punching & tubular members/buckling Tension Piles/Pull out Wind turbine rotor blades/fatigue Ship Structures/Long Series of studies

13. 13 PROCODE Examples Wind turbine rotor blades/fatigue Ronold/C.Christensen Optimisation of design code for wind-turbine rotor blades in fatigue. Eng.str. 23(2001) –Previous work on probabilistic design –Wish to develop code valid for variation of designs, locations and materials –Fatigue in rotor blade root - SN approach –Material is fibre-reinforced polyester laminate

14. 14 PROCODE Examples Wind turbine rotor blades/fatigue Scope Parameters –Rotor radius –chord length –section modulus (blade root) –rotor frequency –hub height –material

15. 15 PROCODE Examples

16. 16 PROCODE Examples

17. 17 PROCODE Examples

18. 18 PROCODE Examples

19. 19 PROCODE Examples

20. 20 PROCODE Examples

21. 21 PROCODE Examples

22. 22 PROCODE Examples