multilayer stress & strength

HillcaiStrength2.m

@@ -0,0 +1,13 @@
+function val=HillcaiStrength(stress,strength,theta)
+%safe if return true
+%use xt,yt as x,y
+
+stress=getRotateMatrix(-theta)*stress;
+s1=stress(1);
+s2=stress(2);
+s12=stress(3);
+X=strength.xt;
+Y=strength.yt;
+S=strength.s;
+val=(s1^2/X^2-s1*s2/X^2+s2^2/Y^2+s12^2/S^2-1);
+end

findLayerZ.m

@@ -0,0 +1,8 @@
+function i=findLayerZ(layerz,z)
+lz=size(layerz);
+lz=lz(1);
+for i=1:lz
+	if z<layerz(i,2)
+		return
+	end
+end

getBoardStiffness.m

@@ -1,9 +1,31 @@
-function [Ak,Bk,Dk]=getBoardStiffness(material,theta,z1,z2)
+function [Ak,Bk,Dk]=getBoardStiffness(material,theta,z1,z2,brokenFlag)
 %theta rad
 %z2>z1
 S=getMaterialMatrixS(material);
 T=getRotateMatrix(theta);
-Qk=T*inv(S)*inv(T);
+Qk=inv(S);
+
+if brokenFlag>0
+	if brokenFlag>=4
+	    Qk(3,3)=0;
+	    brokenFlag=brokenFlag-4;
+	end
+	if brokenFlag>=2
+	    Qk(:,2)=zeros(3,1);
+	    Qk(2,:)=zeros(3,1)';
+        Qk(3,3)=0;
+        brokenFlag=brokenFlag-2;
+	end
+	if brokenFlag>=1
+	    Qk(:,1)=zeros(3,1);
+	    Qk(1,:)=zeros(3,1)';
+        Qk(3,3)=0;
+        brokenFlag=brokenFlag-1;
+	end
+end
+
+Qk=T*Qk*(T)';
+
 Ak=Qk*(z2-z1);
 Bk=Qk/2*(z2^2-z1^2);
 Dk=Qk/3*(z2^3-z1^3);

getBrokenFlag.m

@@ -0,0 +1,20 @@
+function BrokenFlag=getBrokenFlag(thisBrokenResult,stress,strength,theta)
+%syms Nx
+BrokenFlag=0;
+stress=subs(stress,thisBrokenResult);
+T=getRotateMatrix(-theta);
+stress=abs((T)*stress);
+if stress(1)>strength.xt*0.7
+    BrokenFlag=bitor(BrokenFlag,1);
+end
+if stress(2)>strength.yt*0.7
+    BrokenFlag=bitor(BrokenFlag,2);
+end
+if stress(3)>strength.s*0.7
+    BrokenFlag=bitor(BrokenFlag,4);
+end
+
+if BrokenFlag==0
+    warning('something wrong in broken calculate');
+end
+end

getGeneralizedStrainForMultilayer.m

@@ -1,5 +1,5 @@
 function GeneralizedStrain=getGeneralizedStrainForMultilayer(A,B,D,load)
 Q=[A,B;B,D];
 es=inv(Q)*[load.Nx;load.Ny;load.Nxy;load.Mx;load.My;load.Mxy];
-GeneralizedStrain=struct('e0x',es(1),'e0y',es(2),'e0xy',es(3),'kx',es(4),'ky',es(5),'kxy',es(6));
+GeneralizedStrain=struct('e0x',es(1,:),'e0y',es(2,:),'e0xy',es(3,:),'kx',es(4,:),'ky',es(5,:),'kxy',es(6,:));
 end

getMultilayerStiffness.m

@@ -1,7 +1,8 @@
-function [A,B,D]=getMultilayerStiffness(materials,theta,z)
+function [A,B,D]=getMultilayerStiffness(materials,theta,z,brokenFlag)
 %array input
-
-if (length(materials)~=(length(z)-1))||(length(materials)~=(length(theta)))
+lz=size(z);
+lz=lz(1);
+if (length(materials)~=(lz))||(length(materials)~=(length(theta)))||(length(materials)~=(length(brokenFlag)))
     return
 end
 
@@ -10,7 +11,7 @@
 D=zeros(3);
 
 for i=1:length(materials)
-    [Ak,Bk,Dk]=getBoardStiffness(materials(i),theta(i),z(i),z(i+1));
+    [Ak,Bk,Dk]=getBoardStiffness(materials(i),theta(i),z(i,1),z(i,2),brokenFlag(i));
     A=A+Ak;
     B=B+Bk;
     D=D+Dk;

getPointStrain.m

@@ -0,0 +1,7 @@
+function PointStrain=getPointStrain(GeneralizedStrain,z)
+PointStrain=[GeneralizedStrain.e0x+z*GeneralizedStrain.kx;
+    GeneralizedStrain.e0y+z*GeneralizedStrain.ky;
+    GeneralizedStrain.e0xy+z*GeneralizedStrain.kxy;];
+
+
+end

plotBroken.m

@@ -0,0 +1,14 @@
+function plotBroken(BrokenResult,exAfterBroken,exBeforeBroken)
+hold on
+
+xlabel('\epsilon_x')
+ylabel('N_x')
+
+for i=1:length(BrokenResult)-1
+    plot([exAfterBroken(i),exBeforeBroken(i)],[BrokenResult(i),BrokenResult(i+1)],'-')
+    plot(exBeforeBroken(i),BrokenResult(i+1),'s')
+    plot(exAfterBroken(i),BrokenResult(i),'*')
+    %arrow([exAfterBroken(i),BrokenResult(i)],[exBeforeBroken(i),BrokenResult(i+1)])
+end
+
+end