/// <summary>
/// This method builds a <see cref="FiniteElementMethodInput"/> based on <see cref="TwoDegreesOfFreedomInput"/>.
/// It is used in the matricial form of two degrees of freedom solution.
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public Task <FiniteElementMethodInput> BuildFiniteElementMethodInput(TwoDegreesOfFreedomInput input)
{
double[,] mass = new double[, ] {
{ input.Mass, 0 }, { 0, input.SecondaryMass }
};
double[,] stiffness = new double[, ] {
{ input.Stiffness + input.SecondaryStiffness, -input.SecondaryStiffness }, { -input.SecondaryStiffness, input.SecondaryStiffness }
};
double[,] damping = new double[, ] {
{ input.Damping + input.SecondaryDamping, -input.SecondaryDamping }, { -input.SecondaryDamping, input.SecondaryDamping }
};
return(Task.FromResult(new FiniteElementMethodInput
{
Mass = mass,
Damping = damping,
Stiffness = stiffness,
OriginalForce = new double[] { input.Force, 0 },
AngularFrequency = input.AngularFrequency,
AngularFrequencyStep = input.AngularFrequencyStep,
FinalAngularFrequency = input.FinalAngularFrequency,
FinalTime = input.FinalTime,
NumberOfTrueBoundaryConditions = 2,
TimeStep = input.TimeStep,
NumericalMethod = input.NumericalMethod,
ForceType = input.ForceType
}));
}
/// <summary>
/// Calculates and write in a file the results for two degrees of freedom analysis.
/// </summary>
/// <param name="input"></param>
/// <param name="time"></param>
/// <param name="previousResult"></param>
/// <returns></returns>
public virtual async Task <double[]> CalculateTwoDegreesOfFreedomResult(TwoDegreesOfFreedomInput input, double time, double[] previousResult)
{
FiniteElementMethodInput finiteElementMethodInput = await this._mappingResolver.BuildFiniteElementMethodInput(input).ConfigureAwait(false);
FiniteElementResult previousFiniteElementResult = await this._mappingResolver.BuildFiniteElementResult(previousResult, input.Force).ConfigureAwait(false);
FiniteElementResult finiteElementResult = await this.CalculateFiniteElementResult(finiteElementMethodInput, previousFiniteElementResult, time).ConfigureAwait(false);
double[] result = await this._mappingResolver.BuildVariableVector(finiteElementResult).ConfigureAwait(false);
return(result);
}
/// <summary>
/// Calculates the value of the differential equation of motion used for the two degrees of freedom case for a specific time, based on the force and angular frequency that are passed.
/// </summary>
/// <param name="input"></param>
/// <param name="time"></param>
/// <param name="previousResult"></param>
/// <returns></returns>
public async Task <double[]> CalculateForTwoDegreedOfFreedom(TwoDegreesOfFreedomInput input, double time, double[] previousResult)
{
double[] result = new double[Constant.NumberOfRigidBodyVariables_2DF];
double force = await this._force.CalculateForceByType(input.Force, input.AngularFrequency, time, input.ForceType).ConfigureAwait(false);
// Velocity of primary object.
result[0] = previousResult[2];
// Velocity of secondary object.
result[1] = previousResult[3];
// Acceleration of primary object.
result[2] = (force - ((input.Stiffness + input.SecondaryStiffness) * previousResult[0] - input.SecondaryStiffness * previousResult[1] + (input.Damping + input.SecondaryDamping) * previousResult[2] - input.SecondaryDamping * previousResult[3])) / input.Mass;
// Acceleration of secondary object.
result[3] = (input.SecondaryStiffness * (previousResult[0] - previousResult[1]) + input.SecondaryDamping * (previousResult[2] - previousResult[3])) / input.SecondaryMass;
return(result);
}
/// <summary>
/// Calculates and write in a file the results for two degrees of freedom analysis using Runge Kutta Forth Order numerical method.
/// </summary>
/// <param name="input"></param>
/// <param name="time"></param>
/// <param name="previousResult"></param>
/// <returns></returns>
public override async Task <double[]> CalculateTwoDegreesOfFreedomResult(TwoDegreesOfFreedomInput input, double time, double[] previousResult)
{
return(await this.CalculateResult(this._differentialEquationOfMotion.CalculateForTwoDegreedOfFreedom, input, time, previousResult).ConfigureAwait(false));
}
