03 Getzner Glossary
03 Getzner Glossary
03 Getzner Glossary
Table of Contents
0-9
1/3 octave band 4
E
Elastic force [N] Elasticity Elongation at rupture under tensile stress [%] Elongation at tear [%] Emission isolation Energy absorption [Nm] Energy dissipation [Nm] Energy equivalent mean level Evaluation level [dB] Excitation frequency [Hz] 6 6 6 7 7 7 7 7 7 7
A
Abrasion (mm3) Airborne noise Ambient temperature [C] Amplitude Amplitude dependence Amplitude of vibration Angle of loss [degrees] 4 4 4 4 4 4 4
B
Bedding modulus [N/mm3] 4
F
Fatigue test Finite Elements Method (FEM) Footfall noise level [dB] Form factor (q) Frequency [Hz] 7 7 7 7 8
C
Center of gravity Coefficient of friction Complex e-modulus [N/mm2] Compression set [%] Crest factor 4 4 5 5 5
H
Hookes Law 8
D
Dampening of footfall noise [dB] Damping Damping coefficient [1/s] Damping ratio (D) Decade Decibel [dB] Deflection [mm] Deformation energy [Nm] Degree of freedom Degree of transmission [dB] Density [kg/m3] Disturbing frequency [Hz] Dynamic load Dynamic range 5 5 5 5 5 5 6 6 6 6 6 6 6 6
I
Immission isolation Impedance [Ns/m] Insertion loss Insertion loss [dB] Isolating vibration Isolation Isolation efficiency Isolation factor [%] 8 8 8 8 8 8 8 8
L
Level [dB] Load deflection curve Load peaks [N/mm2] Loss factor () Loss modulus 8 8 8 8 9
M
Mass-spring system Mechanical loss factor Modal analysis Modulus of elasticity [N/mm2] Multiple mass oscillator 9 9 9 9 9
N
Natural frequency [Hz] Natural mode Noise emission Noise immission Noise pollution 9 9 9 9 9
O
Octave 10
P
Periodic duration [s] Plasticity Poisson Number [] Polyurethane Pre-load [N] 10 10 10 10 10
Q
Quasi-static deformation Quasi-static load deflection curve 10 10
R
Residual compression set [%] Resistance to strain [N/mm2] Resistance to tear propagation [N/mm] Resonance Resonant frequency [Hz] 10 10 10 10 11
Shearing stress [N/mm2] Shock Shock absorbing elements Shock absorption Shock isolation Shock isolation [%] Shock pulse Shock reduction Shore hardness Single-mass oscillator Sound Sound isolation [dB] Sound pressure [Pa] Sound pressure level [dB] Sound spectrum Sound wave Specific load [N/mm2] Specific volume resistance [cm] Spectrum Spring deflection [mm] Static load range [N/mm2] Static creep behaviour [%] Stationary loading Stiffening factor Stiffness [kN/mm] Storage modulus Structure-borne noise Structure-borne noise isolation [dB] Sum level Ltot
11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 13 13 13 13 13 13 13 13 13 13 13 14 14
V
Velocity level [dBv] Vibration dampening Vibration damping Vibration isolation Vibrations 14 14 15 15 15
T
Tangent modulus [N/mm3] Tangent stiffness [kN/mm] Tensile strength [N/mm2] Tensile stress at rupture [N/mm2] Thermal conductivity [W/mK] Transmission function Tuning frequency [Hz] Tuning ratio 14 14 14 14 14 14 14 14
S
Secant modulus [N/mm3] Secant stiffness [kN/mm] Shear modulus [N/mm2] 11 11 11
A-C
Sylodyn materials exhibit a negligible amplitude dependence. The dynamic stiffness of other elastic materials, At temperatures above the maximum such as compact, foamed and bonded limit permanent damage can occur to rubber products (rubber granule), howthe elastomer, and at temperatures ever, is significantly dependent on the below the minimum limit the elastomer amplitude of excitation. may freeze. The maximum working temperature limit denotes the maximum temperature at which the material can be used without beginning to age, i.e. without an excessive loss of elastic properties. Minimum working temperature: low temperatures reduce the mobility of the molecular chains, causing the elastomer to lose elasticity (this process is reversible for Sylomer and Sylodyn).
Abrasion [mm3]
Parameter for the assessment of abrasion (abrasive wear) against abrasive loss; abrasion is the loss in volume in mm3 of a defined testing body on a test emery surface with a defined attack strength, defined contact pressure over a pre-defined path. Abrasion only reflects actual wear behavior under field conditions to a limited extent.
Amplitude of vibration
See amplitude.
Amplitude
A quantity characterizing a vibration; it is the maximum magnitude of variation of a physical quantity from its zero value to a positive or negative value; amplitude refers to a physical quantity (e.g. force, displacement).
Airborne noise
Sound propagated in the air in the form of sound waves, as opposed to sound transmission through liquids or solid bodies.
Center of gravity
The point to which the entire mass of a system can be reduced; the center of gravity is extremely important for the design of elastic equipment bearings.
Amplitude dependence
Amplitude dependence describes the dependence of the dynamic stiffness on the amplitude of vibration. This characteristic is highly specific to the particular material. Sylomer and
Coefficient of friction
The coefficient of friction represents
C-D
the relationship between frictional resistance to normal forces. The coefficient of friction of an elastomer can be determined for materials such as steel, concrete, wood, etc. A distinction is made between static friction and sliding friction; in the material data sheets the values are stated for sliding friction.
from the initial value A0 (t = 0) to the . value A at the time t A=A0 . e- t Note: not the same as spatial damping coefficients (e.g. degree of absorption in acoustics).
Damping
Transformation of kinetic energy into another form of energy which is no longer relevant (reusable) for the oscillatory system (e.g. heat via abrasion, plastic deformation,); damping (dissipation of energy) takes energy out of the mechanical system. In order to limit resonant vibration to an acceptable range, a mechanical system requires adequate damping. Vibration damping and vibration isolation are two different measures for isolating vibrations. See also loss factor, damping ratio.
Decade
The interval at which the upper interval limit is 10 times higher than the lower limit; decades are used for time and also for frequencies. For example, an interval of 100 to 1000 has a bandwidth of one decade, while an interval of 50 to 5000 has a bandwidth of two decades.
Crest factor
Unit for characterizing the damping of a free oscillator with speed-proporRatio of the crest value to the effective tionate damping; it is calculated as time-related amount of damping; value of a vibration. For sinusoidal " describes the (exponential) timevibrations it is 2 = 1.41. related damping of an oscillation
Decibel [dB]
Unit for expressing the ratio against some physical quantity in terms of the base 10 logarithm of that ratio
D-E
10 log(v1/v2). Logarithmic ratios are described as levels or amounts, e.g. velocity level, insertion loss, etc. For example, sound pressure levels are usually put in ratio as a square equation. The 2 of the square equation in the Log will be set in front of the same becoming 20 log (). Example: the velocity level: Lv = 10 . log(v2/v02) = 10 . log(v/v0)2 = 20 . log(v/v0)dB.
Deflection [mm]
The distance which an elastomer is compressed under a specific load or force.
In respect of vibration isolation characterizes the isolation efficiency as a Dynamic range ratio of input and response forces and/ or input and output amplitudes. This is the load range for an elastomer bearing, which includes both the static loads and the dynamic loads; static loads should be lower than the upper Density [kg/m3] limit of the static load range; dynamic The density (volume weight or specific loads should fall in the range between the maximum static load limit and the mass) is the ratio of the mass to the maximum dynamic load limit. volume for elastomers; testing procedure as per DIN 53420. Elastomer bearings are particularly elastic in this range, i.e. the vibration Disturbing frequency [Hz] isolating effect of the elastomer is utilized to the fullest extent. Frequency applied to excite an oscillatory system, e.g. cyclical forces generated by a machine. Elastic force [N] Recovery force of an elastomer from an external force due to its elastic property.
The energy necessary to cause deforDynamic load mation of an elastomer; can be determined based on the surface area under The elastomer is subject to a forced the force-deformation curve (load sinusoidal vibration. The test paramdeflection curve). eters are frequency, pre-load and amplitude.
Elasticity
Material property which causes elastomers to return to the original form following deformation.
Degree of freedom
Describes the possible directions of motion of an oscillatory system; there are 3 translational degrees of freedom in the 3 spatial axes and 3 rotational degrees of freedom around the 3 spatial axes.
Based on the force and deformation result, the dynamic stiffness, the dynamic modulus of elasticity or dynamic bedding modulus and the mechanical loss factor can be derived. The data sheets usually use the frequencies 10 and 30 Hz with a velocity level of 100 dBv. Testing procedures
E-F
Emission isolation
Vibration isolation consisting of an elastic bearing system for an oscillatory system, so that no disturbing vibrations are emitted into the surroundings.
Fatigue test
A method of testing the long-term behavior of an elastomer by subjecting it to a static and simultaneous dynamic Energy (kinetic or potential) withdrawn load; for rail applications up to 12.5 from the system and transformed into million load cycles (oscillations) are usually necessary. heat per load cycle; calculated based on the hysteresis surface of the load deflection curve.
The Finite Elements Method is a method for numerical modeling of problems in various physical disciplines, in particular strains and deformations of all kinds in elastic and plastic spaces.
F-L
Frequency [Hz]
Number of oscillations per second in a periodic signal.
Insertion loss
Ratio of the power of the vibrations (e.g. power of the structure-borne noise) which is transmitted into the adjacent structure without an elastic element or mounting to that which is transmitted when an elastic element or mounting is present.
Isolation efficiency
See isolation factor.
Hookes Law
Describes the linear relationship between specific load and strain; valid for Sylomer and Sylodyn in the linear Note: insertion loss is only independent of the selected site of measurerange of the load deflection curve. ment if the boundary conditions (e.g. subgrade, building design, tunnel design, etc.) are identical. Immission isolation Vibration isolation of a system (recipient) against disturbing vibrations from the surroundings.
Level [dB]
Logarithmic ratio of a quantity to a reference quantity of the same dimension, cf. decibel.
Impedance [Ns/m]
Also known as characteristic acoustic impedance. The greater the difference between the characteristic acoustic impedances of two media, the more sound energy will be reflected at the boundary surface between the two media, i.e. less sound energy is transmitted. Conversely, this also represents better vibration isolation; For good damping there is a so-called jump in impedance, i.e. a significant difference between the characteristic acoustic impedance of the two media involved.
Isolating vibration
See vibration isolation.
Isolation
see vibration isolation.
Loss factor ()
Damping within a material is described with the mechanical loss factor Ratio
L-N
of energy dissipation and deformation work per cycle; testing procedures as per DIN 53513; see also D damping ratio.
modes in the form of translation, rotais a material property and describes the relationship between specific load tion or bending as well. and strain (Hookes Law). ). The emodulus is dependent on the specific load and load acceleration. Noise emission A distinction is made between static e-modulus (quasi-static deformation) and the dynamic e-modulus (dynamic load). Testing procedures similar to DIN 53513. See also complex e-modulus. Noise emission refers to structureborne noise or airborne noise emitted by a sound source; the sound source is located at the emission location.
Loss modulus
See complex e-modulus.
Mass-spring system
A mass-spring system is a type of superstructure for permanent way consisting of a reinforced concrete trough or slab and a spring (for example an elastomer bearing). The large mass of the concrete trough allows for very low tuning frequencies.
Noise immission
Noise immission is the structureborne noise or airborne noise striking a recipient, regardless of the location of the noise emission (source of the structure-borne or airborne noise). The location of the recipient is referred to as the immission location and the level of sound measured there is known as the immission level.
Modal analysis
A method to experimentally determine modal quantities such as natural frequencies and natural damping of a complex multiple mass oscillator (oscillating system); the quasi-numerical counterpart of modal analysis is FEM analysis (Finite Elements Method).
Noise pollution
Noise is defined as airborne sound, which may be disturbing, annoying, hazardous or damaging. Perception of sounds and noise depends to a great degree on the individual and is thus subjective.
Natural mode
Vibratory systems have natural modes, which can be described by natural frequency, natural damping and vibratory form. A system can have natural
O-R
Octave
An octave is the range (frequency band) between a frequency and twice or one-half of that frequency, i.e. fo= 2 . fu bzw. fu= 1/2 . fo . For example, one octave above and below the frequency 1000 Hz is covered by the intervals to 2000 Hz and 500 Hz. In acoustic measurements, standardized mean octave frequencies (fm) are usually used (fm = 16, 31.5, 63, 125, 250, 500, 1000, 2000 Hz).
Polyurethane
Abbreviation: PUR. Polyurethanes are manufactured by poly addition of isocyanates and polyalcohols and can be produced with cellular structures or compact structures. A distinction is made between polyether urethanes and polyester urethanes.
pression deformation of 40%, with 20 s rise and decay duration of the load ramp. The elastomer is usually prestressed with two preliminary cycles, and measurements are carried out for the third cycle.
Pre-load [N]
Static load which is applied to an elastomer before the application of a dynamic load.
Quasi-static deformation
One time application of a load onto an elastomer, whereby the time period for application of the maximum load is 20 s; see quasi-static load deflection curve.
Plasticity
Material property which leaves an elastomer in a deformed state following deformation.
Poisson Number ()
Ratio of the lateral deformation to the axial deformation; for elastomers the Poisson number (also: Poissons ratio) depends to a great degree on the cellular structure and load.
Resonance
When the disturbing frequency of a
10
R-Sh
system is equal to the natural frequen- Shear modulus [N/mm2] cy of the system, resonance occurs. Occurrence of resonance can lead to Elastomer bearings are able to absorb the destruction of the entire oscillating shearing forces and shearing stress. system. The ratio between shearing stress and By damping the vibratory system it is horizontal deflection of the elastomer possible to limit resonance vibrations is referred to as the shear modulus. to an acceptable degree. Flexibility to a changing force is particularly strong Fundamentally speaking, an elastomer with the resonance range. bearing is softer with regard to shearing loads than with regard to compression loads. The relationship of comResonant frequency [Hz] pression to shearing stiffness ranges between factor 4 and 10, depending on the cellular structure and geometry of Frequency, at which resonance the bearing. The quasi-static shearing occurs. deflection curve exhibits relatively linear deformation behavior. A dynamSecant modulus [N/mm3] ic shearing modulus can be calculated from the dynamic shearing load. Denotes the surface-related stiffness Testing procedures similar to DIN ISO of an elastomer bearing; a secant is 1827. drawn through the interface points of two defined secant points (specific loads) with the load deflection curve. The rise in the secant is referred to as Shearing stress [N/mm2] the secant modulus or bedding modulus. Shearing force per unit of surface area of the elastomer.
Shock absorption
See shock reduction.
Shock isolation
Resilient support for passive vibration isolation of machinery and equipment to protect such from the effects of shocks.
Shock
Sudden, non-periodic vibration (generally caused by shock pulse) which can generally be characterized by a triangular-shaped acceleration impulse. The duration of rise is usually shorter than the duration of decay.
Shock pulse
Sudden application of force; characterized by shock duration, maximum shock force and shock form (half-sine pulse, square pulse).
Denotes the stiffness of an elastomer bearing; a secant is drawn through the interface points of two defined secant points (forces) with the load deflection curve; the rise in the secant is referred to as the secant stiffness.
11
Sh-So
Shock reduction
The goal of shock reduction is to reduce the path or the delay of the impacting mass or to reduce the transmission of force. In doing this, the impact energy of the impacting mass is transformed into heat or deformation energy.
Sound
Smallest pressure and density oscillations in an elastic medium in the audible range of humans from approximately 16 Hz to 20,000 Hz, e.g. airborne sound, structure-borne noise, sound transmitted through liquids. Lower frequencies are referred to as infrasound and higher frequencies as ultrasound.
evaluation, the frequency sensitivity of the ear is realized via the so-called A-weighting, and reference is made to the A-weighted sound level (also known as sound level in dB[A]). In addition to this frequency weighting, there are also three different time averaging options that can be selected in the measurements. These three options are: Fast: Rise duration = 125 ms; Decay duration = 125 ms; Slow: Rise duration = 1.0 s; Decay duration = 1.0 s; and impulse: Rise duration = 35 ms; Decay duration = 1.5 s; it is particularly important to indicate the time averaging for impulse and burst sound events.
Shore hardness
Shore hardness is a measurement for the hardness of rubbers for example and can only be used to a limited degree with foamed elastomers. The measurement of Shore hardness is the resistance to indentation of a body of defined shape with force applied by a calibrated spring. There are two hardness scales: the Shore A scale for soft (rubbery) materials and the Shore D scale for harder materials. The measurement for the hardness or elasticity of foamed elastomers is the modulus of elasticity.
Sound spectrum
A graphic representation of sound as a function of frequency. Depending on the type of frequency filter used in the analysis, one can primarily distinguish between spectra in octaves, 1/3 octave bands or narrow band spectra. In comparing various spectra, it is important to take into account the bandwidth of the filter used in the analysis.
Single-mass oscillator
Applications for vibration isolation are often postulated on an oscillatory system with one degree of freedom consisting of a mass and a spring.
is twenty times the 10 base logarithm Sound wave of the ratio of the instantaneous sound pressure to the reference sound presA motion with periodic changes in the sure (audible threshold); For practical position of molecules (vibration), applications in noise abatement and whereby the energy of this vibration
12
Sp-St
propagates at the speed of sound while the individual molecules (e.g. air molecules) oscillate around a static point.
static modulus of elasticity or the static bedding modulus. Normally, elastomers begin to experience creep after a load is applied.
Stiffening factor
The spring deflection properties of elastomers depend on the acceleration of deformation. The ratio between the dynamic and static stiffness stiffness is referred to as the stiffness factor (or ratio of dynamic to static).
Stiffness [kN/mm]
Describes the elasticity of an elastomer to deformation; can be determined using force-displacement measurement; the steepness of the forcedisplacement curve (see load deflection curve) represents the stiffness; stiffness is dependent on load acceleration (quasi-static or dynamic). A distinction is drawn between secant stiffness and tangent stiffness.
Increase in deformation under steady, long-term load. When Sylomer and Sylodyn are subjected to loads as stated in the static load range, the increase in deformation is lower than Spectrum 20% even after 10 years. Increases in deformation of this order of magniGraphic representation of a physical tude have also been observed in elasquantity (ordinate) as a function of frequency (abscissa). A pure sinusoi- tomer bridge bearings. Testing procedal vibration, for example, is represent- dure as per DIN ISO 8013. ed as a line in a line spectrum. Naturally occurring vibrations are rarely pure sinusoidal vibrations; therefore, in order to determine the frequencies comprising the largest portion of the vibration it is expedient and/or necessary to represent it graphically as a spectrum. The largest portions are
Storage modulus
See complex e-modulus.
Stationary loading
The elastomer is subject to a static load which does not vary over time. If the specific load and the resulting deflection are known, it is possible to determine the static stiffness, the
Structure-borne noise
Are vibrations transmitted via solid or liquid bodies
13
St-V
The force that must be applied per unit of a standardized cross-section to cause the elastomer to rupture; tensile stress at rupture is a minimum value; Note that structure-borne noise isolatesting procedure as per DIN EN ISO tion should not be confused with struc- 527. ture-borne noise damping.
Tuning ratio
Ratio of the disturbing frequency to the tuning frequency of an elastically-mounted system; also known as frequency ratio; the disturbing frequency and the tuning frequency must be separated by at least a factor of 2 to achieve isolation of the system.
Transmission function
In respect of vibration isolation the isolation efficiency as a ratio of input and response forces and/or input and output amplitudes.
Vibration dampening
A method of vibration reduction in-
14
volving the removal of energy from an oscillatory system by the attachment of an vibration dampener; the dampener consists of an oscillatory system (e.g. mass, spring and damper) and vibrates at its resonance.
Vibration damping
See damping.
Vibration isolation
Reduction of the transmission of mechanical vibrations by the installation of elastic components; a distinction is drawn between the reduction of vibration transmission from a source of vibration into the surroundings (reduction of emissions, isolation of the emission source) and the shielding of an object from the impact of vibrations from the surroundings (reduction of immissions, isolation of an object). See also immission isolation and emission isolation.
Vibrations
Vibrations are processes in which a physical quantity changes periodically depending on time; these physical quantities can be displacements, accelerations, forces, momentum.
15
Getzner Werkstoffe GmbH Herrenau 5 6706 Brs Austria Phone +43-5552-201-0 Fax +43-5552-201-899 info.buers@getzner.com Getzner Werkstoffe GmbH Am Borsigturm 11 13507 Berlin Germany Phone +49-30-405034-00 Fax +49-30-405034-35 info.berlin@getzner.com Getzner Werkstoffe GmbH Nrdliche Mnchner Str. 27a 82031 Grnwald Germany Phone +49-89-693500-0 Fax +49-89-693500-11 info.gruenwald@getzner.com
Getzner Werkstoffe GmbH Middle East Regional Office Abdul - Hameed Sharaf Str. 114 Rimawi Center - Shmeisani P. O. Box 961 303 Amman 11196, Jordan Phone +9626-560-7341 Fax +9626-569-7352 info@geme.jo Nihon Getzner K.K. Landmark Plaza, 8F Shiba Koen 1-6-7, Minato-ku 105-0011 Tokyo Japan Phone +81-3-5402-5340 Fax +81-3-5402-6039
www.getzner.com
www.getzner.com
climate neutral printing