torsional_spring Derived Type

type, public, extends(torsional_force_element) :: torsional_spring

Defines a linear torsional spring about a revolute-joint axis.

Contents

Variables

free_angle joint_index stiffness

Type-Bound Procedures

evaluate_torque

Components

Type	Visibility	Attributes		Name		Initial
real(kind=real64),	public		::	free_angle	=	0.0d0	The zero-torque relative joint angle, in radians.
integer(kind=int32),	public		::	joint_index	=	0	The one-based revolute-joint index whose axis the element uses.
real(kind=real64),	public		::	stiffness	=	0.0d0	The torque per unit angular displacement.

Type-Bound Procedures

procedure, public :: evaluate_torque => torsional_spring_torque

private pure function torsional_spring_torque(this, angle, angle_rate) result(rst)

Evaluates the restoring torque produced by a linear torsional spring.

Arguments

Type	Intent	Optional	Attributes		Name
class(torsional_spring),	intent(in)			::	this	The spring whose stiffness and free angle define the torque law.
real(kind=real64),	intent(in)			::	angle	The relative joint angle and angular rate. The rate is unused by a torsional spring.
real(kind=real64),	intent(in)			::	angle_rate	The relative joint angle and angular rate. The rate is unused by a torsional spring.

Return Value real(kind=real64)

The signed torque applied to the child body about the joint axis.