ASTM D4848-98

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Designation: D 4848 – 98
Standard Terminology of
Force, Deformation and Related Properties of Textiles
This standard is issued under the fixed designation D 4848; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
TABLE 1 Relationship of Force and Deformation Terms
1. Scope
Mathematical
1.1 This terminology standard is a compilation of defini-
Term Symbol Unit
Expression
tions of technical terms related to force and deformation
Length L mm (in.)
properties when evaluating a stress-strain curve of a textile.
Extension DL mm (in.)
(See Figs. X1.1 and X1.2.) A chart showing the relationship of
Strain DL/L
Elongation DL/L 3 100 %
the basic terms is shown in Table 1. Terms that are generally
A
Linear density D tex (den)
understood or adequately defined in other readily available
2 2
Cross-sectionalAmm (in. )
sources are not included.
area
Force F N (lbf)
1.2 For other terms associated with textiles, refer to Termi-
Tension T N (lbf)
nology D 123.
Strength S N (lbf)
A B
Tenacity F/D mN/tex (lbf/den)
2 2 B
2. Referenced Documents
Stress F/A N/m (lbf/yd )
A
2.1 ASTM Standards: In computers, this may be given as “LD” instead of “D ”.
B 2
2 For fibers, these inch-pound units are usually gf/den and gf/in.
D 123 Terminology Relating to Textiles
3. Terminology
DISCUSSION—Breaking toughness is represented by the area and the
stress-strain curve from the origin to the breaking force per unit length,
breaking elongation—See elongation at break.
and, in textile strands, is expressed as work (joules) per unit of linear
breaking force, n—the maximum force applied to a material
density of the material. In textile fabrics, the unit is joules per gram.
carried to rupture. (Compare breaking point, breaking
chord modulus, n—in a stress-strain curve, the ratio of the
strength. Syn. force-at-break)
change in stress to the change in strain between two specified
DISCUSSION—Materials that are brittle usually rupture at the maxi-
points on the curve.
mum force. Materials that are ductile usually experience a maximum
compression, n—the act, process, or result of compacting,
force before rupturing.
condensing, or concentrating.
breaking load—deprecated term. Use the preferred term compressive force, n—the perpendicular force applied to
surface(s) of a material in compaction.
breaking force.
breaking point, n—on a force-elongation curve, or stress- compression recovery, n—the degree to which a material
returns to its original dimension(s) after removal of a
strain curve, the point corresponding with the breaking force
or the breaking stress in a tensile test. (Compare breaking compressive force.
compression resistance, n—the ability of a material to oppose
force.)
breaking strength, n—strength expressed in terms of breaking deformation under a compressive force.
corresponding elongation—See elongation at specified force.
force. (See also breaking force and strength. Syn., strength
at break) corresponding force—See force-at-specified-elongation.
deformation, n—a change in shape of a material caused by
breaking tenacity, n—the tenacity at the breaking force. (See
also breaking force, tenacity.) forces of compression, shear, tension, or torsion.
breaking toughness, n—toughness up to the breaking force of
DISCUSSION—Deformation may be immediate or delayed. Delayed
a material.
deformation may be either recoverable or nonrecoverable.
deformation, permanent, n—the net long-term change in a
dimension of a specimen after deformation and relaxation
This terminology is under the jurisdiction of ASTM Committee D13 on Textiles
under specified conditions. (Syn. permanent set, nonrecov-
and is the direct responsibility of Subcommittee D13.58 on Yarn and Fiber Test
Methods. erable deformation, and nonrecoverable stretch.
Current edition approved April 10, 1998. Published July 1998. Originally
DISCUSSION—Permanent deformation is usually expressed as a per-
published as D 4848 – 88. Last previous edition D 4848 – 97.
Annual Book of ASTM Standards, Vol 07.01. centage of the original dimension.
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D 4848
DISCUSSION—Force is properly expressed in newtons (N) or multiples
delayed deformation, n—deformation which is time-
and submultiples of newtons, for example kilonewtons (kN) and
dependload of a skein of yarn adjusted for the linear density
millinewtons (mN). Force is also expressed as grams-force (gf),
of the yarn expressed in an indirect system.
kilograms-force (kgf), or pounds-force (lbf), but the use of these terms
is deprecated.
DISCUSSION—Deformation may be recoverable or nonrecoverable
following removal of the applied force.
force at break, n—See breaking force.
elastic limit, n—in mechanics, the maximum stress which can
force at rupture, n—the force applied to a material immedi-
be obtained in a material without causing permanent defor-
ately preceding rupture. (Compare breaking force. See also
mation of the material. (Compare yield point.)
rupture.)
DISCUSSION—Elastic limit is a property of a material whereas yield
DISCUSSION—Materials that are brittle usually rupture at the maxi-
point is a specific point on a stress-strain curve.
mum force. Materials that are ductile usually experience a maximum
force before rupturing.
elasticity, n—that property of a material by virtue of which it
force at specified elongation (FASE), n—the force associated
tends to recover its original size and shape immediately after
with a specific elongation on the force-extension or force-
removal of the force causing deformation.
elongation, n—the ratio of the extension of a material to the elongation curve. (Syn. corresponding force.)
force-deformation curve, n—a graphical representation of the
length of the material prior to stretching, expressed as a
percent. force and deformation relationship of a material under
conditions of compression, shear, tension or torsion. (Com-
DISCUSSION—Elongation may be measured at any specified force or at
pare force-elongation curve, force-extension curve and
rupture.
stress-strain curve.)
elongation at break, n—the elongation corresponding to the
DISCUSSION—Force-deformation related curves include force-
breaking force. (Compare elongation at rupture. See also
extension, force-compression, force-shear (displacement), force-torque
elongation.) Syn. breaking elongation.
and stress-strain curves. The shape of the force-extension curve of a
elongation at the breaking load, n—deprecated term. Use the
material and the shape of the corresponding stress-strain curve are the
preferred term elongation at break.
same, only the units are different. Force is expressed in such units as
elongation at specified force, (EASF), n—the elongation newton, kilogram-force, pound force. In tension, shear or compression
tests, deformation is expressed in such units of length as metre,
associated with a specified force on the force-extension
millimetre or inches. In torsion tests, deformation is expressed in such
curve. (Syn. corresponding elongation).
units for plane angles as radians or degrees.
elongation at rupture, n—the elongation corresponding to the
force-at-rupture. (Compare elongation at break.)
force-elongation curve, n—a graphical representation of the
force and elongation relationship of a material under tension.
DISCUSSION—The elongation at rupture for a brittle material is usually
(Compare force-deformation curve, force-extension curve
equal to the elongation at break; but for ductile materials this elongation
and stress-strain curve.)
may be greater.
force-extension curve, n—a graphical representation of the
extensibility, n—that property by virtue of which a material
force and extension relationship of a material under tension.
can undergo extension or elongation following the applica-
(Compare force-deformation curve, force-elongation
tion of sufficient force.
curve and stress-strain curve.)
extension, n—the change in length of a material due to
immediate elastic recovery, n—recoverable deformation
stretching. (Compare elongation.)
which is essentially independent of time, that is, occurring in
(a time approaching) zero time and recoverable in (a time
DISCUSSION—Extension may be measured at any specified force or at
rupture and is expressed in units of length, for example, millimetres and
approaching) zero time after removal of the applied force.
inches.
(Compare delayed deformation and delayed elastic recov-
ery.)
extension-recovery cycle, n—in tension testing, the continu-
initial modulus, n—in a stress-strain curve, the slope of the
ous extension of a specimen, with a momentary hold at a
initial straight-line portion of the curve.
specified extension, followed by a controlled rate of return to
knot breaking force, n—in tensile testing, the breaking force
zero extension.
of a strand having a specified knot configuration tied in the
failure, n—an arbitrary point beyond which a material ceases
portion of the strand mounted between the clamps of a
to be functionally capable of its intended use. (Compare
tensile testing machine. (Compare knot breaking strength.
rupture.)
See also breaking force.)
DISCUSSION—A material may be considered to have failed without
knot breaking load, n—deprecated term. Use the preferred
having ruptured.
term, knot breaking force.
force, n—a physical influence exerted by one body on another knot breaking strength, n—strength expressed in terms of
which produces acceleration of bodies that are free to move knot breaking force. (See also knot breaking force.)
linear density, n—mass per unit length.
and deformation of bodies that are not free to move.
(Compare strength.) load—deprecated term. Use the preferred term, force.
D 4848
load, vt—to apply a force. skein breaking tenacity, n—the skein breaking strength di-
vided by the product of the yarn number in direct numbering
DISCUSSION—Although the terms load and force are frequently used
system and the number of strands placed under tension.
interchangeably to denote the same phenomena, ASTM has adopted use
of the technically correct term force.
DISCUSSION—Observed breaking strength can be converted to break-
ing tenacity by dividing the breaking strength by the product of the yarn
load at specified elongation (LASE)—deprecated term. Use the
measured in a direct numbering system and the number of strands
preferred term, force at specified elongation (FASE).
placed under tension (twice the number of wraps in the skein).
load-deformation curve, n—deprecated term. Use the preferred
strain, n—deformation of a material caused by the application
term, force-deformation curve.
of an external force.
load-elongation curve, n—deprecated term. Use the preferred
term, force-elongation curve.
DISCUSSION—Strain is usually expressed as a ratio involving exten-
loop breaking force, n—in tensile testing, the breaking force
sion.
of a specimen consisting of two lengths of strand from the
strength, n—the property of a material that resists deformation
same supply looped together in a specified configuration and
induced by external forces. (Compare force.)
mounted between the clamps of a tensile testing machine.
(Compare loop breaking strength. See also breaking
DISCUSSION—Strength may be expressed in units of force for a
specific material or units of stress. Traditionally, some have considered
force.)
strength to be an average of individual values rather than the individual
loop breaking load, n—deprecated term. Use the preferred
values.
term, loop breaking force.
loop breaking strength, n—strength expressed in terms of
strength at break, n—See breaking strength.
loop breaking force. (See also loop breaking force,
strength at rupture, n—strength expressed in terms of the
strength.)
force at rupture. (Compare breaking strength.)
modulus, n.—the property of a material representative of its
stress, n—the resistance to deformation developed within a
resistance to deformation. (See also chord modulus, initial
material subjected to an external force.
modulus, tangent modulus, Young’s modulus).
DISCUSSION—Stress is the result of strain and vice versa. In textiles,
pretension, n—the specified tension applied to a specimen
stress is expressed in units of force per unit cross-sectional area. Typical
preparatory to making a test.
examples are tensile stress, shear stress, or compressive stress.
DISCUSSION—Pretension may be used to establish a uniform baseline
stress decay, n—in mechanics, the reduction in force to hold a
for a test. In tensile testing, the pretension is usually a low force
material at a fixed deformation over a period of time.
designed to remove kinks, crimp or wrinkles and essentially straighten
and align the specimen as it is being mounted in the testing machine.
DISCUSSION—This is a generic definition. Stress is already defined.
The stress decay is due to adsorption of energy.
recovery, delayed elastic—See delayed elastic recovery.
recovery immediate elastic—See immediate elastic recovery.
stress-strain curve, n—a graphical representation of the stress
recovery tensile strain—See tensile strain recovery.
and strain relationship of a material under conditions of
rupture, n—the breaking or tearing apart of a material.
compression, shear, tension, or torsion. (Compare force-
(Compare failure.)
deformation curve, force-elongation curve, and force-
extension curve.)
DISCUSSION—As applied to tensile testing, rupture refers to the total
separation of a material into two parts either all at once or in stages, or
DISCUSSION—In tension tests of textile materials, the stress may be
the development of a hole in some materials.
expressed either in (1) units of force per unit cross-sectional area, or (2)
units of force per unit linear density of the original specimen, and the
secant modules, n—deprecated term in textile terminology.
strain may be expressed either as a fraction or as a percentage of the
Use the preferred term chord modulus.
original specimen length.
single-strand breaking force, n—in tensile testing, the break-
tangent modulus, n—in a stress strain curve, the ratio of the
ing force of one strand that follows a specified path, usually
change in stress to the change in strain derived from the
a straight line, between the clamps of a tensile testing
tangent at any point on the curve.
machine. (Compare breaking force.)
tenacity, n—in a tensile test, the force exerted on the specimen
single-strand strength, n—deprecated term. Use single-strand
based on the linear density o
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