q_stress.m

ABAQUS is a general purpose finite element analysis program which is widely used to analyses mechani

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function [Q_total,Q_pl,st2nd]=Q_stress(Tnd,lirv2,hard,rx);
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% hardening rate  3,6,13 or nh for nonhardening	                 %
% The modified boundary layer formulations for the 4 hardening	 %
% rates is extimated from FE-analysis as described in Karstensen,%
% Nekkal and Hancock, "Constraint Estimation Sceme I : Single 	 %
% Edge Gemometries in Tension and Bending", 1994		 %
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%  	Initiation of Constants Value				 %
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	status=0;
	
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  if hard=='06'
	  ssy=5.28*(1/rx)^0.21;		
	  stress=ssy+0.48*Tnd-0.25*Tnd.^2;
    

   elseif hard=='13'
          ssy=3.83*(1/rx)^0.10;
	  stress=ssy+0.64*Tnd-0.4*Tnd.^2;
     

   elseif hard=='03'
	  ssy=8.06*(1/rx)^0.32;
	  stress=ssy+0.21*Tnd-0.08*Tnd.^2;
		


   elseif hard=='nh'
	  ssy=2.875;
	  stress=ssy+0.83*Tnd-0.876*Tnd.^2;
   else
         'Warning in Q-stress : unrecognised hardening rate'
         status=-1;
   end
   


     if status==0
        Q_total=lirv2-ssy;
	Q_pl=lirv2-stress;
	st2nd=lirv2./stress;
    end	

end; 		% (* end of Q_stress function *) %