// return initial stiffness matrix const XC::Matrix &XC::Twenty_Node_Brick::getInitialStiff(void) const { static Matrix K; K= getStiff(0); if(isDead()) K*=dead_srf; return K; }
//====================================================================== const Matrix &EightNode_Brick_u_p::getInitialStiff (void) { return getStiff(0); }
//====================================================================== const Matrix &EightNode_Brick_u_p::getTangentStiff (void) { return getStiff(1); }