U è dichiarata nel file.h
#ifndef SteelSte_h
#define SteelSte_h
#include <UniaxialMaterial.h>
class SteelSte : public UniaxialMaterial
{
public:
SteelSte(int tag, double ES, double FY, double L, double DS, double TD, double U1, double KH, double lp);
SteelSte(void);
virtual ~SteelSte();
const char *getClassType(void) const {return "SteelSte";};
double getInitialTangent(void);
UniaxialMaterial *getCopy(void);
int setTrialStrain(double strain, double strainRate = 0.0);
double getStrain(void);
double getStress(void);
double getTangent(void);
int commitState(void);
int revertToLastCommit(void);
int revertToStart(void);
int sendSelf(int commitTag, Channel &theChannel);
int recvSelf(int commitTag, Channel &theChannel,
FEM_ObjectBroker &theBroker);
void Print(OPS_Stream &s, int flag =0);
double u;
protected:
private:
.......
};