7 





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 Nonconservative 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 Stressstrain 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 [DRIVINGPOINT] 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 Timecontinuous dynamical system described by a set of ordinary differential equations, in which time does not appear explicitly. Note: Nonautonomous 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 selfexcitation, 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. Timecontinuous system described by an autonomous set of firstorder differential equations (flow). 2. Timediscrete 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. 