Detailed Description

Time-dependent subdomain deactivation.

Subdomain deactivation is space and time-dependent. The spatial extent of deactivated elements is defined through an intersection between a half-space and a set of material ids. The half-space is defined by a line segment that separates through its normal plane and position on the line segment an active and an inactive part.

The subdomain can be deactivated at once using a time interval. For fine-grained control, a time curve can be specified. It maps the current time to the position given as distance (in length units) between the start and the end points on the line segment. Elements, which center points lie left of this position are deactivated.

The deactivated elements are excluded from the assembly, pre and post call, secondary variables computation and the like. To keep the size of the global linear equation system artificial Dirichlet boundary conditions are applied on the interior of the deactivated subdomain. The nodes on the border between the active and inactive elements are not affected.

Definition at line 87 of file DeactivatedSubdomain.h.

#include <DeactivatedSubdomain.h>

Collaboration diagram for ProcessLib::DeactivatedSubdomain:

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Public Member Functions
bool	isInTimeSupportInterval (double const t) const

bool	isDeactivated (MeshLib::Element const &element, double const time) const

Public Attributes
MathLib::PiecewiseLinearInterpolation	time_interval

std::optional< std::pair< Eigen::Vector3d, Eigen::Vector3d > >	line_segment

std::optional< detail::Ball >	ball
	The shape of the deactivated domain is a ball, which is a disk for 2D.

DeactivatedSubdomainMesh	deactivated_subdomain_mesh

ParameterLib::Parameter< double > const *	boundary_value_parameter

Static Public Attributes
static PROCESSLIB_EXPORT const std::string	zero_parameter_name

Member Function Documentation

◆ isDeactivated()

bool ProcessLib::DeactivatedSubdomain::isDeactivated	(	MeshLib::Element const &	element,
		double const	time ) const

Returns: true if the element is in the deactivated part of the subdomain. If the line segment is available additionally the element's centre point is used to evaluate if the element is already, depending on time curve, active or inactive. For this the domain is split into two parts by a plane defined as a normal plane of the line segment and the position on the line segment, where the latter is defined by the time curve.

Definition at line 33 of file DeactivatedSubdomain.cpp.

{
    auto const& bulk_element_ids = deactivated_subdomain_mesh.bulk_element_ids;
    if (!bulk_element_ids.contains(element.getID()))
    {
        return false;
    }
 
    if (line_segment)
    {
        auto const& element_center = getCenterOfGravity(element);
        // Line from a to b.
        auto const& a = line_segment->first;
        auto const& b = line_segment->second;
        // Tangent vector t = (b - a)/|b - a|.
        Eigen::Vector3d const t = (b - a).normalized();
 
        // Position r on the line at given time.
        auto const curve_position = time_interval.getValue(time);
        Eigen::Vector3d const r = a + t * curve_position;
 
        // Return true if p is "behind" the plane through r.
        return (element_center.asEigenVector3d() - r).dot(t) <= 0;
    }
 
    if (ball)
    {
        auto const& element_center = getCenterOfGravity(element);
 
        auto const& center = ball->center;
        // The radius at given time.
        auto const r_t = time_interval.getValue(time);
        if (r_t > ball->radius)
        {
            return false;
        }
 
        double const r_element_center =
            (element_center.asEigenVector3d() - center).norm();
 
        return r_element_center < r_t;
    }
 
    return true;
}