LoadIncrementalStateResult GetCorrection(LoadState state, LoadIncrementalState prediction, StructureInfo info)
{
Matrix <double> stiffnessMatrix = info.Stiffness(state.Displacement);
Vector <double> dut = stiffnessMatrix.Solve(info.ReferenceLoad);
Vector <double> reaction = info.Reaction(state.Displacement);
Vector <double> equilibrium = info.InitialLoad + state.Lambda * info.ReferenceLoad - reaction;
Vector <double> dur = stiffnessMatrix.Solve(equilibrium);
LoadIncrementalStateResult incrementalStateResult = Scheme.GetCorrection(state, prediction, info, dut, dur);
return(incrementalStateResult);
}
/// <summary>
/// Predicts a LoadIncrementalState.
/// </summary>
/// <param name="state"></param>
/// <param name="initialStiffness"></param>
/// <returns></returns>
internal LoadIncrementalStateResult Predict(LoadState state, double initialStiffness, StructureInfo info)
{
Vector <double> equilibrium = info.InitialLoad + state.Lambda * info.ReferenceLoad - info.Reaction(state.Displacement);
Matrix <double> mK = info.Stiffness(state.Displacement);
Vector <double> Dvt = mK.Solve(info.ReferenceLoad);
Vector <double> Dvr = mK.Solve(equilibrium);
double bergam = GetBergamParameter(initialStiffness, Dvt, info);
double DLambda = Scheme.GetPrediction(Dvt, info.ReferenceLoad) * Math.Sign(bergam);
Vector <double> Dv = DLambda * Dvt + Dvr;
return(new LoadIncrementalStateResult(new LoadIncrementalState(DLambda, Dv), true, ""));
}