7

Dynamics, supplement

English


7.1 AGGREGATE
System consisting of a load, transmission and a source of energy, the last being of limited power.
7.2 AGGREGATE, MACHINE
Aggregate consisting of a driven machine, a transmission and a driving machine of limited power.
7.3 ANGLE, PRESSURE
Angle between vectors of force and velocity of a point at which the force is applied.
7.4 ANGLE, TRANSMISSION
Angle which is 90 degrees minus pressure angle.
7.5 CHARACTERISTIC, DRIVE
Dependence of the generalized force upon the generalized velocity of a drive.
7.6 CHARACTERISTIC, DYNAMIC DRIVE
1. Drive characteristic described by a set of differential and possibly algebraic equations which must be added to model equations. 2. Particular solution of a model with drive or its graphical representation at steady state or transient state.
7.7 CHARACTERISTIC, STATIC DRIVE
Drive characteristic at steady state with constant speed.
7.8 CHARACTERISTIC, FRICTION
Ratio of the magnitude of a frictional force to the magnitude of the normal component of a reaction as a function of the relative sliding velocity of the contacting points expressed in an analytical and/or graphical and/or tabulated form.
7.9 CONDITIONS, BOUNDARY
Set of values and/or functions which must be satisfied by continuous system variables and their spatial derivatives at given points due to the constraints of the system.
7.10 EFFICIENCY
Measure of utilizing a quantity (mostly energy) within a system at steady state.
7.11 FACTOR, ELASTICITY [DYNAMIC*]
Ratio of some value obtained under consideration of elastic links to the same value obtained under the assumption of rigid links.
7.12 FORCE {MOMENT}, DRIVING
Force {moment} generated by an external source of energy.
7.13 FORCE, FOLLOWER
Non-conservative force which changes its line of action according to the deformation of a system to which it is applied. Usually the line of action coincides with a tangent to the elastic axis of the system in a point of action of the force.
7.14 FORCE {MOMENT}, RESISTANT
Force {moment} applied to the driven (output) link of a mechanism.
7.15 FORCE {MOMENT}, RESTORING
Force {moment}depending upon an elastic displacement of a system from its equilibrium state and acting in the opposite sense to the elastic displacement.
7.16 FRICTION, COULOMB
Idealization of dry (sliding) friction with frictional force independent of relative velocity, but proportional to normal component of the reaction.
7.17 FRICTION, DRY
Friction between surfaces of two contacting bodies at sliding without any intermediate lubricant film.
7.18 HYSTERESIS
Stress-strain relationship on unloading differs from that on loading.
7.19 IMPEDANCE, ANGULAR MECHANICAL
Impedance given by the ratio of applied torque to resulting angular velocity.
7.20 IMPEDANCE, DIRECT [DRIVING-POINT]
Mechanical impedance with force and velocity measured at the same point of a system.
7.21 IMPEDANCE, MECHANICAL
Impedance given by the ratio of applied generalized force to resulting generalized velocity.
7.22 IMPEDANCE, TRANSFER
Mechanical impedance with force and velocity measured at different points (or in different directions at the same point) of a system.
7.23 MOTION {REGIME} (OF A MACHINE), QUASISTATIC
Motion {regime} of a machine when its kinetic energy is constant.
7.24 MOTION {REGIME} (OF A MACHINE), TRANSIENT
Motion {regime} of a machine when its kinetic energy is not fluctuating in a steady manner.
7.25 PARAMETER
Special value of a quantity of a system which describes or determines physical property, characteristic or behaviour of the system or its part, whereby the value can be a constant or can vary discretely or continuously.
7.26 POINT OF ACTION OF A FORCE
Point of a body to which a force is applied.
7.27 QUANTITY
Physical or mathematical entity, or its amount or property measurable or countable in terms of a number, degree or magnitude and expressible by means of a symbol and particular values.
7.28 STATE {MOTION}, {REGIME}, QUASISTATIC
Steady state {motion}, {regime} in which kinetic energy of a system is constant.
7.29 STATE, STATIC
State in which kinetic energy of a system is zero.
7.30 STATE {MOTION}, {REGIME}, STEADY
(Dynamic) state {motion}, {regime} of a system when its kinetic energy varies in a periodic manner.
7.31 STATE {MOTION}, {REGIME}, TRANSIENT
State {motion}, {regime} of a system when its kinetic energy is not periodic or constant.
7.32 SYSTEM, AUTONOMOUS
Time-continuous dynamical system described by a set of ordinary differential equations, in which time does not appear explicitly. Note: Non-autonomous equations can be rendered autonomous by identifying the time as an extra phase coordinate governed by the dummy equation t′ = 1.
7.33 SYSTEM, AUTOPARAMETRIC
System consisting at least of two subsystems where one subsystem represents, due to external- and/or self-excitation, a source of parametric excitation for another subsystem.
7.34 SYSTEM, CONSERVATIVE
System within and upon which act only conservative forces.
7.35 SYSTEM, DETERMINISTIC
System whose equations of equilibrium, of motion, parameters and initial conditions are known and are not stochastic or random. However, deterministic system may have motions that appear random.
7.36 SYSTEM, DYNAMICAL
1. Time-continuous system described by an autonomous set of first-order differential equations (flow). 2. Time-discrete system described by the difference equations or iterated mapping [map].
7.37 SYSTEM, NONLINEAR
System in which at least one characteristic is nonlinear.
7.38 SYSTEM, PARTIAL VIBRATION
Any mechanical vibration system obtained from a given one with finite number of generalized coordinates when only one from the set of the generalized coordinates oscillates while others are constant.
7.39 VALUE, STATIONARY
Value of a characteristic of a quantity in a stationary state {process}.
7.40 VARIABLE
Quantity that can acquire a finite or infinite sequence of values.
7.41 VARIABLE, DEPENDENT
Variable, the value of which is determined by values of independent variables and parameters.
7.42 VARIABLE, INDEPENDENT
Variable, the value of which is not determined by other variables such as time or space coordinate.