void ElTawil2D::getGradient(double &gx, double &gy, double x, double y)
{
// check if the point is on the surface
double drift = getDrift(x, y);
double loc = forceLocation(drift);
double capx = capXdim;
double capy = capYdim;
if(loc != 0)
{
opserr << "ERROR - ElTawil2D::getGradient(double &gx, double &gy, double x, double y)\n";
opserr << "Force point not on yield surface, drift = " << drift << " loc = " << loc <<"\n";
// opserr << "\a";
gx = 1.0;
gy = 1.0;
}
else
{
double a = 10.277;//3.043;//4.29293; //by compatibility, check err in gradient
// double yt = 0.95;
if(y > ytPos)
{
gx = 2*a*x/capx;
gy = 1;
}
else if(y < ytNeg)
{
gx = 2*a*x/capx;
gy = -1; //-1*y/capy; <-- why did i write this?// -1 ?
}
else
{
// double xVal = x*capx;
double yVal = fabs(y*capy); //!!
// double yVal = y*capy; //!!
gx = 1/xBal;
if(x < 0)
gx = -1*gx;
if(y < 0)
gy = -1*(1/pow( fabs(yNegCap), ty))*ty*(pow(yVal,ty-1));
else
gy = (1/pow(yPosCap, cz))*cz*(pow(yVal,cz-1));
}
}
// opserr << "gx = " << gx << ", gy = " << gy << ", capy = " << capy << "\n";
// opserr << "\a";
}
void Hajjar2D::getGradient(double &gx, double &gy, double xi, double yi)
{
// check if the point is on the surface
double drift = getDrift(xi, yi);
//!! why is capXdim not here??
/*if(drift < -error)
{
opserr << "ERROR - Hajjar2D::getGradient(double &gx, double &gy, double x, double y)\n";
opserr << "Point inside the yield surface\n";
opserr << " fx = " << xi << ", fy = " << yi << " drift = " << drift << "\n";
opserr << "\a";
}
else if(drift > error)
{
opserr << "ERROR - Hajjar2D::getGradient(double &gx, double &gy, double x, double y)\n";
opserr << "Point outside the yield surface\n";
opserr << " fx = " << xi << ", fy = " << yi << " drift = " << drift << "\n";
opserr << "\a";
}*/
if(forceLocation(drift)!=0)
{
opserr << "ERROR - Hajjar2D::getGradient(double &gx, double &gy, double x, double y)\n";
opserr << "Force point not on the yield surface\n";
opserr << " fx = " << xi << ", fy = " << yi << " drift = " << drift << "\n";
opserr << "\a";
}
else
{
double x = xi;
double y = yi /*- centroidY*/;
gx = 2*c1*x + 2*c3*pow(y, 2)*(x);
gy = 2*c2*y + 2*c3*pow(x, 2)*(y);
}
}
