LoadPath
#include <analysis/integrator/LoadPath.h>LoadPath is a subclass of StaticIntegrator,
it is used to when performing a static analysis on the
FE_Model using a user specified load path. The load path is
specified in a Vector, path, to the objects constructor and
at each step in the analysis:
\[ \lambda_n^{(i)} - \lambda_{n-1} = \texttt{path}[n] - \texttt{path}[n-1] \]
Knowing \(\lambda_n^{(i)} = path(n)\) prior to each iteration, the \(N+1\) unknowns in equation staticFormTaylor, is reduced to \(N\) unknowns and results in the following equation:
\[\boldsymbol{r}(\boldsymbol{u}_{n}) = \lambda_n^{(i)} \boldsymbol{p}_f - \boldsymbol{p}_{\sigma}\left(\boldsymbol{u}_{n}^{(i)} \right) - \boldsymbol{K}_n^{(i)} (\boldsymbol{u}_{n} - \boldsymbol{u}_{n}^{(i)}) \label{staticFormLoadPath}\]
Methods
A vector object path is created which is a copy of
loadPath and an index into this vector is set to \(0\).
The integer INTEGRATOR_TAGS_LoadPath (defined in
<classTags.h>) is passed to the StaticIntegrator
classes constructor. No vector object is created. Provided for the
FEM_ObjectBroker to create a blank object, recvSelf()
should be invoked on this object.
Invokes the destructor on the vector path.
The object obtains the current value of \(\lambda\) from the path vector
using the current index. The index is then incremented by \(1\). If the index is greater than the size
of path, \(\lambda\) is
set to \(0\) and an error message is
printed. It will then invoke applyLoadDomain(0.0, \(\lambda\)) on the AnalysisModel
object. Returns \(0\) if successful. A
warning message is printed and a \(-1\)
is returned if no AnalysisModel is associated with the object.
int update(const Vector &$\Delta U$);Invoked this causes the object to first increment the DOF_Group
displacements with \(\Delta U\), by
invoking incrDisp(\(\Delta
U)\) on the AnalysisModel, and then to update the domain, by
invoking updateDomain() on the AnalysisModel. Returns \(0\) if successful, a warning message and a
\(-1\) is returned if no AnalysisModel
is associated with the object.
int Print(OPS_Stream &s, int flag = 0);The object sends to \(s\) its type, the current value of \(\lambda\).