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cmat2dmat

PURPOSE

Computes the (Palmgren-Miner) damage matrix from a cycle matrix.

SYNOPSIS

Dmat = cmat2dmat(param,F,beta,K)

DESCRIPTION

CMAT2DMAT Computes the (Palmgren-Miner) damage matrix from a cycle matrix.

CALL:  Dmat = cmat2dmat(param,F,beta,K)

Input:
Dmat  = Damage matrix.                     [nxn]
Output:
param = Parameter vector, [a b n], defines discretization.
F     = Cycle matrix.                      [nxn]
beta  = beta exponent.                     [1x1]
K     = K-value, material parameter (Optional, Default: 1) [1x1]

Example:
param = [-1 1 32]; F = mktestmat(param);
Dmat = cmat2dmat(param,F,6);
cmatplot(Dmat)

CROSS-REFERENCE INFORMATION

This function calls:
 levels Calculates discrete levels given the parameter matrix. error Display message and abort function.
This function is called by:
 Chapter4 % CHAPTER4 contains the commands used in Chapter 4 of the tutorial itmkurs_lab2 Script to computer exercises 2 itmkurs_lab4 Script to computer exercises 4 rfcdemo2 Rainflow matrix for Switching Markov Chains of Turning Points. rfmextrapolate Extrapolates a rainflow matrix.

SOURCE CODE

001 function Dmat = cmat2dmat(param,F,beta,K)
002 % CMAT2DMAT Computes the (Palmgren-Miner) damage matrix from a cycle matrix.
003 %
004 % CALL:  Dmat = cmat2dmat(param,F,beta,K)
005 %
006 % Input:
007 %   Dmat  = Damage matrix.                     [nxn]
008 % Output:
009 %   param = Parameter vector, [a b n], defines discretization.
010 %   F     = Cycle matrix.                      [nxn]
011 %   beta  = beta exponent.                     [1x1]
012 %   K     = K-value, material parameter (Optional, Default: 1) [1x1]
013 %
014 % Example:
015 %   param = [-1 1 32]; F = mktestmat(param);
016 %   Dmat = cmat2dmat(param,F,6);
017 %   cmatplot(Dmat)
018 %
020
021 % Tested on Matlab 6.0
022 %
023 % History:
024 % Revised by PJ  04-Jan-2000
025 % -  updated for WAFO
026 % Created by PJ (Pär Johannesson) 1997
027 %   from 'Toolbox: Rainflow Cycles for Switching Processes V.1.0'
028
029
030 % Check input and otput
031
032 ni = nargin;
033 no = nargout;
034 error(nargchk(3,4,ni));
035
036 if ni < 4
037   K=[];
038 end
039
040 % Set default values
041
042 if isempty(K)
043   K = 1;
044 end
045
046 % Calculate damage matrix
047
048 n = length(F);
049 u=levels(param);
050 Dmat = zeros(n,n);
051
052 for i=1:n-1
053   for j=i+1:n
054     Dmat(i,j) = ((u(j)-u(i))/2)^beta*F(i,j);
055   end
056 end
057
058
059

Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

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