Method formResidAndTangent

SRC/element/shell/ShellNLDKGT.cpp:1380–1811

form residual and tangent

//form residual and tangent
void  
ShellNLDKGT::formResidAndTangent( int tang_flag ) 
{
	//
	//six(6) nodal dof's ordered:
	//-----------
	//|    u1    |   <---- plate membrane
	//|    u2    |
	//|----------|
	//|   w = u3 |  <----plate bending
	//|   theta1 |
	//|   theta2 |
	//|----------|
	//|   theta3 |  <- drill (tran from membrane)
	//|----------|
  // membrane strains ordered :


	static const int ndf = 6; //two membrane + 3 moment +drill

	static const int nstress = 8; //3 membrane , 3 moment, 2 shear

	static const int ngauss = 4;

	static const int numnodes = 3;

	int i,j,k,p,q;
	int jj,kk;
	int jlast,jnew; //add for geometric nonlinearity

	int p1,q1;

	int p2,q2;

	int p3,q3;

	int pp,qq;

	int success;

	double volume = 0.0;

	static double xsj; //determinant jacobian matrix

	static double dvol[ngauss]; //volume element

	//add for geometric nonlinearity
	static Vector incrDisp(ndf); //total displacement

	static Vector Cstrain(nstress);//commit strain last step/ add for geometric nonlinearity

	static Vector strain(nstress); //strain

	//add for geometric nonlinearity
	static Vector dstrain(nstress);   //total strain increment
	static Vector dstrain_li(nstress); //linear incr strain
	static Vector dstrain_nl(3);//geometric nonlinear strain