1. MARINTEK/CeSOS , Trondheim, Norway
On the counting of maxima (short contribution)
Carl Trygve Stansberg
MARINTEK/CeSOS , Trondheim, Norway
CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

2. Consider a simplified quadratic model for slow-drift responses
y(t) =  df HR(f) e j 2f t  df0 N*(f-f0/2) N(f+f0/2)
(i.e. a linearly filtered wave energy envelope)
HR(f) = {1/(C √[422 + (1-2)2])} e-j arctg[2/(1-)]
(linear oscillator)
(re: Stansberg (2000) – OMAE)
CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

3. CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

4. CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

5. Number of slow-drift maxima in a given record N = Tduration / T:. T =
Number of slow-drift maxima in a given record N = Tduration / T: T = ? T = Tz  T2? May be OK for narrow-banded waves. Not necessarily OK for slow-drift maxima Alternative: N = Tduration /  where  = correlation length of time signal, based on spectral bandwidth of response signal, e.g.:
CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

6. CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

7. CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

8. ”Hidden
maxima”
Reasonable
agreement
Correlated
maxima
CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006

9. Number of slow-drift maxima in a given record N = Tduration / T:. T =
Number of slow-drift maxima in a given record N = Tduration / T: T = ? T = Tz  T2? May be OK for narrow-banded waves. Not necessarily OK for slow-drift maxima Alternative: N = Tduration /  where  = correlation length of time signal, based on spectral bandwidth of response signal, e.g.:
CeSOS Workshop on Research Challenges in Probabilistic Load and Response Modelling, Trondheim, Norway, 24th March 2006