Engee documentation

Torsional Spring-Damper

Rotating spring-damper connection with Coulomb friction, locking and rigid stops.

blockType: Engee1DMechanical.Elements.Rotational.SpringDamper

torsional spring damper

Path in the library:

/Physical Modeling/1D Mechanical/Couplings & Drives/Torsional Spring-Damper

Description

Block Torsional Spring-Damper It consists of a rotary spring and a damper that create a combination of internal torques between the two connected axes of the drive shaft, the rod and the housing. The unit determines the torque using the following characteristics:

  • Linear damping spring.

  • Coulomb friction (including blocking static friction).

  • Pliability with a hard stop.

This block is a composite component consisting of the following blocks:

Block Contribution Library

Loaded-Contact Rotational Friction

Coulomb friction

Physical Modeling/1D Mechanical/Brakes & Detents/Rotational

Rotational Damper

Dampening

Physical Modeling/Fundamental/Mechanical/Rotational/Elements

Rotational Spring

Spring

Rotational Hard Stop

Hard focus

Assumptions and limitations

Taking into account the rigid stop and Coulomb friction increases the accuracy of the model, but reduces the simulation speed.

Ports

Conserving

# R — base surface port
rotational mechanics

Details

A mechanical rotary port connected to the rod.

Program usage name

rod_flange

# C — port of the driven (movable) surface
rotational mechanics

Details

A mechanical rotary port connected to a shaft that moves between stops mounted on the housing.

Program usage name

case_flange

Parameters

Spring-Damper

# Spring stiffness — stiffness of the rotary spring
N*m/rad | mN*m/rad | kN*m/rad | kgf*m/rad | lbf*ft/rad | N*m/deg | mN*m/deg | kN*m/deg | kgf*m/deg | lbf*ft/deg | W*s/rad | HP_DIN/rpm | HP_DIN*s/rad

Details

The stiffness of the rotary spring acting on the connected drive shafts.

Units

N*m/rad | mN*m/rad | kN*m/rad | kgf*m/rad | lbf*ft/rad | N*m/deg | mN*m/deg | kN*m/deg | kgf*m/deg | lbf*ft/deg | W*s/rad | HP_DIN/rpm | HP_DIN*s/rad
Default value

1000.0 N*m/rad
Program usage name

k
Evaluatable

Yes

# Viscous friction coefficient — coefficient of viscous friction of rotation
N*m/(rad/s) | ft*lbf/(rad/s)

Details

The coefficient of rotational friction acting on the connected drive shafts.

Units

N*m/(rad/s) | ft*lbf/(rad/s)
Default value

10.0 N*m/(rad/s)
Program usage name

viscous_coefficient
Evaluatable

Yes

# Coulomb friction torque — kinetic moment of friction
N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft

Details

A constant kinetic moment of friction acting on the connected drive shafts. This constant torque prevents rotation at any speed.

Units

N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft
Default value

0.0 N*m
Program usage name

T_coulomb
Evaluatable

Yes

# Ratio of static to kinetic friction — the ratio of static and kinetic friction

Details

The constant value of the ratio of the static moment of Coulomb friction to the kinetic moment of Coulomb friction acting on the connected drive shafts. The value must be greater than or equal to one.

Default value

1.1
Program usage name

static_to_kinetic_friction_torque_ratio
Evaluatable

Yes

# Velocity tolerance — tolerance for speed difference of connected drive shafts
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

The minimum relative angular velocity below which two connected drive shafts can lock and rotate together.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

0.001 rad/s
Program usage name

w_slip_threshold
Evaluatable

Yes

Hard Stops

# Hard stop — simulation of a rigid stop

Details

Turn on or off the torque during a hard stop:

  • Uncheck this option to increase the simulation speed by eliminating the torque during a hard stop.

  • Select this option to increase the accuracy of the simulation by turning on the torque during a hard stop.

Default value

false (switched off)
Program usage name

enable_hardstop
Evaluatable

No

Initial Conditions

# Initial deformation — the value of the initial deformation
rad | deg | rev | mrad | arcsec | arcmin | gon

Details

The initial deformation of the rotary spring relative to the reference angle of the torque reference.

Units

rad | deg | rev | mrad | arcsec | arcmin | gon
Default value

0.0 deg
Program usage name

delta_phi_start
Evaluatable

Yes