Path dependent loop in Matlab

Question

Arifian 2015-2-13

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/178224-path-dependent-loop-in-matlab

Hi,

Right now I am doing riser-soil interaction model. The interaction between them is path-dependent which means if the response follow certain conditions it will follow certain path. Right now, I manage it by using for-loop but it will become cumbersome if the interaction become more complex. My question is there any efficient method to simulate path-dependent process within matlab? I thought of using while-loop but I am not so sure.

Here is my present code:

%SOIL MODEL
clear all
clc
%Parameter
fsuc=0.203;
w=0.433;
phi=0.661;
S0=800;
Sg=0;
k0=660*S0;
T=10;                               %Period of motion [s]
w0=2*pi/T;                          %Frequency of motion [rad/s];
D=0.2032;                           %Pipe diameter [m]
%Motion Definition
t=0:0.05:100;                       %Time definition
Y1=100;                             %Dummy/Initial Backbone point 
Y2=80;
Y3=60;
I=100;
for i=1:length(t)
    y(i)=0.06*sin(w0*t(i));          %Motion definition
    %BACKBONE CURVE (INITIAL PENETRATION)
    P(i)=bbone(y(i),D,S0,Sg);
    if i>2
    if (y(i)<y(i-1)&&y(i-1)>y(i-2))
        Y1=y(i-1);                                 %Backbone Point
        I=i-1;
        P1=bbone(Y1,D,S0,Sg); 
        Y2=Y1-(((1+w)*P1/k0)*((1+fsuc)/(w-fsuc)));
        Y3=Y2-phi*(Y1-Y2);
        P2=-fsuc*P1; 
    end
      if(y(i)<Y1 && y(i)<y(i-1) && y(i)>Y2)          %Point 1 to Point 2
          P(i)=P12(y(i),Y1,P1,k0,w,-1);
      elseif (y(i)<Y1 && y(i)>y(i-1) && y(i)>Y2)
          Yrb=y(i);
          Prb=P12(Yrb,Y1,P1,k0,w,-1);
          P(i)=P12(y(i),Yrb,Prb,k0,w,1);
      end
      if (y(i)<Y2 && y(i)>Y3 && y(i)<y(i-1))         %Point 2 to Point 3
          P(i)=P23(y(i),Y2,Y3,P2);
      elseif (y(i)<Y2 && y(i)>Y3 && y(i)>y(i-1))
          Yrb=y(i);
          Prb=P23(y(i),Y2,Y3,P2);
          P(i)=P31r(y,Y1,Yrb,P1,Prb);
      end
      if (y(i)<Y3 && i>I)                            %Full separation
          P(i)=0;
      end
      if (y(i)>Y3 && y(i)>y(i-1) && y(i)<=Y1)        %Point 3 to Point 1
          P(i)=P31(y(i),Y1,Y3,P1);
      end
      if (y(i)>Y1 && y(i)>y(i-1))
          P(i)=bbone(y(i),D,S0,Sg);
      end
      end
  end