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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. PROCODE. PROCODE was developed in the early nineties in the Reliability of Marine Structures Project
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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
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
PROCODE • Objective • Optimisation of partial safety factors • Control Variables: Partial Safety Factors • Minimum Scatter around a target reliability by minimising the penalty function
PROCODE • SCOPE of code is specified by design cases • External and Internal Conditions are specified separately • External: • External could be environmental conditions (Hs,Tz) • Conditions are associated with a Name-Set • PROCODE take care of the Name-Set and Names that points to the PROBAN variables during execution
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
PROCODE • The scope is defined by the design cases defined by combining external and internal conditions
PROCODE • Variables • X, stochastic • E, environment • D, design situation • , design parameters that may be chosen by the designer
PROCODE • Limit State Function: G(X,E,D,)>0 • Code Check Function: h(x,e,d,,)>= 0 • M failure modes k=1-M • Nk code check functions n=1- Nk • Code check requirements: hnk(x,ei,di, ij, ) >= 0 • Limit State functions: Gk(X,Ei,Di,ij) >= 0 • i,j defining the scope matrix
PROCODE One design Case: Subjected to: With one of the inequalities turning into equality This is generalised to Multiple design cases in PROCODE
PROCODE • Programmable functions • Limit States • Code Checks • Penalty functions • Defined by Data (additional to PROBAN) • Scope (Internal, Internal) • Safety Factor • Design Parameter
PROCODE RESULTS • Code Evaluation (before optimisation starts) • Optimised partial safety factors • Resulting reliabilities • Resulting design parameters (input to cost analysis)
PROCODE Examples • Jack-up, spudcan/punching & tubular members/buckling • Tension Piles/Pull out • Wind turbine rotor blades/fatigue • Ship Structures/Long Series of studies
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
PROCODE Examples • Wind turbine rotor blades/fatigue • Scope Parameters • Rotor radius • chord length • section modulus (blade root) • rotor frequency • hub height • material
