ISO 23718:2007 金属材料—機械的テスト—用語, 語彙 | ページ 5

1.5.1.1

吸収されたエネルギー

K

試験片と衝突する直前の打撃部材の位置エネルギーと、試験片の破壊後に部材に残るエネルギーとの差。風損と摩擦損失が補償された、機械上の読み取り装置によって与えられます。

1.5.1.2

実際の吸収エネルギー

kv or ku

振り子衝撃試験機で試験するときに試験片を破壊するのに必要な総エネルギー

注記 1:振り子の開始位置から試験片が破壊される最初の半振りの終了までの位置エネルギーの差に等しい。

1.5.1.3

アンビル

ストライカーおよび試験片サポートに対して衝撃に備えて試験片を適切に配置し、ストライカーの荷重下で試験片を支持する機械の部分。

注記 1:アンビルの支持端の平面は試験片支持体の平面に垂直であり、ストライカーの前縁に平行である。

1.5.1.4

シャルピー衝撃試験

2 つのアンビルで支えられた試験片に振り子が衝突して破壊したときに、振り子から吸収されるエネルギーを測定する衝撃試験

1.5.1.5

衝撃試験

靱性を評価するための試験。多くの場合、ノッチ付きまたは事前に亀裂を入れた試験片を使用して実行され、通常は試験片によって吸収される位置エネルギーの観点から定量化されます。

1.5.1.6

横方向の拡張

ル

試験片が完全に破壊される直前に、ノッチの反対側に形成される最終プラスチックヒンジにおける試験片の幅の増加

1.5.1.7

脆性破壊の割合

試験片の全破壊面積に対する脆性破壊の面積の割合

脆性破壊とは、多数の結晶粒が劈開破壊や結晶間破壊を起こして輝かしく見える破壊のことです。

1.5.1.8

延性破壊率

試験片の全破壊面積に対する延性破壊面積の割合

注記 1: 延性破壊とは、繊維のせん断破壊によって引き起こされる、薄暗くて光沢のない破壊です。

1.5.1.9

せん断破壊率

破壊が開始されるノッチの付け根where の領域、および試験片の側面および残りの靭帯の最終破断領域に特有の破壊の表面特徴。壊れたシャルピー V ノッチ試験片で定量化し、使用することができます。体心立方晶鉄基合金の延性を推定する

注記 1:この用語は歴史的に延性破壊または脆性破壊のパーセントのいずれかで定量化されてきましたが、この用語はせん断破壊領域 (延性) の「額縁」が比較的平坦な破壊を囲む古典的な場合にのみ当てはまります。へき開（脆性）破壊のゾーン。最新の鋼は、延性破壊と脆性破壊の特徴が混在する平らな破壊領域を形成する可能性があるため、この用語は混乱を招く可能性があります。

1.5.1.10

ストライカー

試験片に接触する振り子の部分

注記 1: 試験片に実際に接触するエッジの半径は 2 mm (2 mm ストライカー) または 8 mm (8 mm ストライカー) です。

1.5.1.11

試験片サポート

振り子、ストライカー、およびアンビルの衝撃の中心に対して、衝撃のために試験片を適切に配置するために機能する機械の部分

注記 1:サポートの平面は、アンビルの平面およびストライカーの前縁に対して垂直である。

1.5.1.12

遷移曲線

材料が延性破壊挙動から脆性破壊挙動に変態する温度範囲にわたる、試験温度と吸収エネルギー（またはせん断破壊パーセントまたは横方向膨張率）との関係を示す曲線

1.5.1.13

転移温度

吸収エネルギーが急激に減少（または増加）し、破壊モードが延性から脆性に変化する現象に対応する温度

1.5.1.14

ノッチしてるよ

U 字型断面、指定された深さと谷の半径を持つノッチ

1.5.1.15

Vノッチ

V 字型断面、指定された深さと谷の半径を持つノッチ

1.1.1

crack growth

crack extension

Δa

change in crack length

Note 1 to entry: It is expressed in millimetres.

1.1.2

crack length

a

length of crack measured from load line to crack tip in the CT specimen, from the perpendicular bisector of the central crack to crack tips in the MT specimen, and from the specimen front face to crack tip in the bend specimen

1.1.3

crack length

crack size

a

a linear measure of a principal planar dimension of a crack from a reference plane to the crack tip

Note 1 to entry: It is expressed in millimetres.

1.1.4

ductility

ability of a material to deform plastically without fracturing

1.1.5

elastic limit

maximum stress that a material is capable of sustaining without any permanent strain remaining upon complete release of the stress

1.1.6

force

F

external influence which would cause an unrestrained test piece to accelerate and which induces stresses in a restrained test piece

1.1.7

mechanical properties

those properties of a material that are associated with elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain

1.1.8

mechanical testing

any tests for the determination of mechanical properties

1.1.9

modulus of elasticity

Young's modulus

E

ratio of stress to corresponding strain below the proportional limit

Note 1 to entry: Young’s modulus is the special case of elastic modulus for normal stress and linear strain.

1.1.10

Poisson's ratio

ν

ratio of transverse strain to the corresponding axial strain resulting from an axial stress below the proportional limit of the material

1.1.10.1

transverse strain

linear strain perpendicular to the applied force

1.1.10.2

axial strain

linear strain in the direction of the applied force

1.1.10.3

axial stress

stress component in the direction of the applied force

1.1.11

range

Δ

algebraic difference between the maximum and minimum values of a variable

1.1.12

strain

relative deformation caused by a force applied to a test piece

1.1.12.1

engineering strain

e

axial strain calculated as the change in length divided by the original length

1.1.12.2

linear strain

strain component in a given linear direction

1.1.12.3

true strain

ε

natural logarithm of the ratio of an instantaneous length to its original length in the direction of the applied force up to the onset of necking

1.1.13

stress

localised intensity of forces within a test piece

1.1.13.1

engineering stress

S

axial stress calculated on the basis of the original cross-sectional area

1.1.13.2

normal stress

stress component perpendicular to a given plane

1.1.13.3

true stress

σ

axial stress calculated on the basis of the instantaneous cross-sectional area

1.1.14

test piece

specimen

portion or piece of material to be used for a single test and normally prepared to a predetermined shape and dimensions

1.1.15

uncertainty of measurement

U, u

parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably be attributed to the measurand

Note 1 to entry: See ISO Guide to the Expression of Uncertainty in Measurement (GUM).

1.2.1

creep curve

curve relating strain and time in a creep test

1.2.2

creep rupture time

t_u

time required for the test piece, maintained at the specified temperature, T , and strained by the specified tensile stress, to rupture

Note 1 to entry: The symbol t_u may have as superscript the specified temperature, T , in Celsius degrees (°C) and as subscript the initial stress, σ_o, in newtons per square millimetre (N/mm²⁾.

1.2.2.1

creep elongation time

t_fx

time required for a strained test piece to obtain at the specified values of temperature, T , and initial stress, σ_o, a specified percentage creep elongation, x

1.2.2.2

plastic elongation time

t_px

time required to obtain at the specified values of temperature, T , and initial stress, σ_o, a specified percentage plastic elongation, x

1.2.3

creep strength

stress to cause specified strain in given time during a creep test at a specified constant temperature

1.2.4

creep test

test to measure the change in strain as a function of time with the test piece held at constant temperature and under constant force or constant stress

1.2.5

elongation

increase in the original gauge length, L_o, or reference length, L_r, at any moment during the test

1.2.5.1

percentage elongation

A

elongation, expressed as a percentage of the original gauge length or reference length

1.2.5.2

percentage creep elongation

A_f

Note 1 to entry:A_f may have the specified temperature, T , in Celsius degrees (°C) as superscript and the initial stress, σ_o, in megapascals (MPa) and time t in hours (h) as subscript.

Note 2 to entry: By convention, the beginning of creep-elongation measurement is the time at which the initial stress, σ_o, is applied to the test piece.

1.2.5.3

percentage elongation after creep rupture

A_u

Note 1 to entry:A_u may have the specified temperature, T , in Celsius degrees (°C) as superscript, and the initial stress, σ_o, in megapascals (MPa) as subscript.

1.2.5.4

percentage initial plastic elongation

A_i

non-proportional increase of the original reference length, L_ro, due to the application of the test force

1.2.6

extensometer

device for measuring extension and transversal dimensional changes

1.2.7

gauge length

L

length of the section of the test piece on which elongation is measured

1.2.7.1

extensometer gauge length

L_e

length of the parallel portion of the test piece used for the measurement of extension by means of an extensometer

Note 1 to entry: In some cases, L_e = L_o.

1.2.7.2

final gauge length

L_u

gauge length after fracture of the test piece

1.2.7.3

original gauge length

L_o

gauge length before application of force

1.2.8

initial stress

σ_o

testapplied force divided by the original cross-sectional area, S_o, of the test piece

1.2.9

maximum force

F_m

maximum force which the test piece withstands during the test

1.2.10

maximum force

F_m

maximum force which the test piece withstands during the test after the beginning of discontinuous yielding

1.2.11

parallel length

L_c

parallel length of the reduced section of the test piece

1.2.12

proof strength, non-proportional extension

R_p

stress at which the plastic extension is equal to a specified percentage of the extensometer gauge length, L_e

Note 1 to entry: The symbol used is followed by a suffix giving the prescribed percentage, for example R_p0,2.

1.2.13

proportional limit

greatest stress which a material is capable of sustaining without any deviation from proportionality of stress to strain

Note 1 to entry: The proportional limit depends on the level of observation used to record the data or results of the test.

1.2.14

percentage reduction of area

Z

1.2.15

reference length

L_r

base length used for the calculation of elongation

1.2.16

stress-strain curve

curve representing the relation between nominal stress and corresponding strain of the parallel portion of the test piece throughout the whole process of tensile testing

1.2.17

tensile strength

R_m

stress corresponding to the maximum force, F_m

Note 1 to entry: It is calculated as the ratio between the maximum force during a tensile test carried to rupture and the original cross-sectional area of the specimen.

1.2.18

tensile test

test that involves straining a test piece by tensile force, generally to fracture, for the purpose of determining one or more of the tensile properties

1.2.19

yield strength

stress corresponding to the point reached during the test at which plastic deformation occurs without any increase in the force

1.2.19.1

lower yield strength

R_el

lowest value of stress during plastic yielding, ignoring any initial transient effects

1.2.19.2

upper yield strength

R_eH

maximum value of stress prior to the first decrease in force

1.3.1

bend test

test which consists in submitting a test piece to plastic deformation by bending until a specified angle of bend is reached

Note 1 to entry: The absence of visible cracks is considered as evidence that the test piece withstood the bend test.

1.3.2

bend test of tube

bending a straight tube in full section around a grooved former of a specified radius, r , until the angle of bend α reaches the value specified in the relevant product standard

1.3.3

degree of planar anisotropy

Δr

coefficient calculated using the formula, Δ r = (r₀ + r₉₀ − 2r₄₅)/2

1.3.4

drift-expanding test of tube

expansion of the end of the test piece cut from the tube, by means of a conical mandrel, until the maximum outside diameter reaches the value specified in the relevant product standard

1.3.5

earing test

test in which cylindrical cups are formed from circular blanks taken from metal sheets or strips, and the height of any earing produced by this process is measured

1.3.6

Erichsen cupping index

ie

measured depth of the cup in the Erichsen cupping test

1.3.7

Erichsen cupping test

test which consists in forming a cup shape by pressing a punch with a spherical end against a clamped test piece between a blank holder and a die until a through crack appears

1.3.8

flattening test of tube

test which consists in flattening the end of a tube or a test piece of specified length, cut from a tube in a direction perpendicular to the longitudinal axis of the tube, until the distance between platens measured under load in the direction of flattening reaches a value specified in the relevant product standard

1.3.9

flanging test of tubes

forming a flange on the end of a test piece cut from the tube, in a plane perpendicular to the axis of the tube, until the external diameter of the flange reaches the value specified in the relevant product standard

1.3.10

formability

capability of a material to be formed into a required form without the occurrence of fracture, localized thinning, or wrinkling

1.3.11

formability test

test to compare formability of materials by using forming limits determined by a process in which a test piece is shaped by deformation working analogous to actual forming until cracking occurs, by a test tool with standardized form and dimension

1.3.12

forming-limit diagram

FLD

a forming-limit curve, the extent to which the material can be formed by drawing, stretching or any combination of drawing and stretching

1.3.13

plastic strain ratio

r_e

ratio of the true width strain and true thickness strain in a test piece that has been submitted to uniaxial tensile stress

1.3.14

ring-expanding test of tubes

expanding a ring cut from the end of a tube, over a conical mandrel until fracture, or until the expansion of the test piece reaches the value specified in the relevant product standard

1.3.15

strain hardening exponent

n

exponent of the true strain in the mathematical equation relating the true stress σ to the true strain ε

Note 1 to entry: During uniaxial application of a force: σ = K · ε ⁿ

1.3.16

torsion test of wire

test to examine the number of times of twisting rotation, aspect of fracture surface, state of torsion, etc. at the time of fracture ここで, both ends of the test piece are gripped tightly with the specified free length between grips and one end is rotated while stretching, so as not to show deflection

1.3.16.1

simple torsion test of wire

test which consists of twisting a test piece of wire around its own axis in one direction

1.3.16.2

reverse torsion test of wire

test which consists of a twist through 360° in one direction followed by another twist through 360° in the opposite direction

1.3.17

wrapping test of wire

test to examine the state of occurrence of breaking, flaws, etc. by wrapping a test piece tightly around a mandrel of a specified diameter until it reaches the specified number of turns

1.4.1

Brinell hardness

HBW

measure of a material's resistance to permanent indentation when a test force is applied through a hardmetal ball indenter

1.5.2.1

construction line

line drawn on the J -Δ a or the δ-Δ a test record, thought to represent crack extension (as reflected in crack surfaces displacement) associated with crack-tip blunting

Note 1 to entry: This term was formerly referred to as blunting line.

1.5.2.2

crack-extension resistance curve

R -curve

variation in δ or J with stable crack extension, ∆ a

1.5.2.3

crack plane orientation

disposition of crack in terms of the direction of the normal to the crack plane and the direction of intended crack extension during the test, referencing the characteristic grain-flow direction of the wrought product from which the test specimen is extracted

1.5.2.4

crack-mouth opening displacement

CMOD

V

relative displacement of crack surfaces normal to the original (undeformed) crack plane, measured at or near the crack-starter notch opening

1.5.2.5

crack-tip opening displacement

δ

relative displacement of crack surfaces normal to the original (undeformed) crack plane, measured at the location of the original crack tip (i.e. tip of the fatigue precrack)

1.5.2.6

critical J

value of J associated with the onset of crack extension

1.5.2.7

critical δ

value of δ associated with the onset of crack extension

1.5.2.8

fracture toughness

generic term for resistance to crack extension under quasistatic, monotonic loading (i.e. crack displacement)

1.5.2.9

J -integral

path-independent, closed-contour line or surface integral that characterizes the local stress-strain field at the crack tip and provides the energy release rate for cases where plasticity effects are not negligible

Note 1 to entry: The J -integral characterizes the change in potential energy for virtual crack extension a.

Note 2 to entry: As such, material is treated as non-linear elastic (by applying the deformation theory of plasticity) in its deformation behaviour.

1.5.2.10

J-R curve

plot of J versus Δ a , descriptive of stable crack-extension resistance for cases where plasticity effects are not negligible

1.5.2.11

maximum fatigue-stress intensity factor

K_f

maximum value of K during the final stages of fatigue precracking

1.5.2.12

mode

one of three manners of crack surface displacement

Note 1 to entry: The Arabic numerals 1, 2, and 3 are used for the general case, representing tensile opening, in-plane sliding, and tearing (or anti-plane shear), respectively. Roman numerals are used to specify the mode as plain strain (I and II) or as antiplane-strain (III).

1.5.2.13

plane-strain opening-mode stress intensity factor

K₁

magnitude of plane-strain elastic stress field singularity at the tip of a crack in a homogeneous body subjected to opening mode displacement (mode I)

Note 1 to entry: A function of applied force, crack length, and test specimen size and geometry; has dimensions of force times length to the power −3/2.

1.5.2.14

plane-strain fracture toughness

K_Ic

measure of a material’s resistance to crack-extension when the stress state near the crack tip is predominantly plane strain, plastic deformation is limited, and opening mode (mode I) loading is applied

Note 1 to entry: This is a specific value of K_I.

1.5.2.15

pop-in

abrupt discontinuity in the force versus displacement record, featured as a sudden increase in displacement and, generally, a decrease in force

1.5.2.16

specimen elastic compliance

C

ratio of displacement increment to force increment

Note 1 to entry: It is the reciprocal of specimen stiffness.

1.5.2.17

specimen span

S

distance between support rollers (i.e. points of application of the reaction force) in a three-point bend test setup

1.5.2.18

specimen thickness

B

distance between the parallel sides of a test specimen

1.5.2.19

specimen width

W

distance from a reference surface or line (for example, the front edge of a bend specimen or the load line of a compact specimen, respectively) to the rear surface of the specimen

1.5.2.20

stable crack extension

crack extension that stops when the progress of applied displacement is interrupted

1.5.2.21

stress intensity factor

K

magnitude of the ideal-crack-tip stress field singularity for a particular mode of crack displacement in a homogenous linear-elastic body

1.5.2.22

stress intensity factor range

ΔK

1.5.2.23

stretch zone width

SZW

length of crack extension that occurs during crack-tip blunting; that is prior to the onset of unstable crack extension, pop-in or slow stable crack extension, and which occurs in the same plane as the fatigue precrack.Virtual crack extension associated with crack-tip blunting that precedes the onset of unstable crack extension, pop-in, or slow stable crack extension, and is similar to the original (undeformed) fatigue precrack

1.5.2.24

unstable crack extension

abrupt crack extension occurring with or without prior stable crack extension

1.6.1

amplitude

a, amp

half the range of a variable

Note 1 to entry: Used typically as a subscript; e.g. ε a, for strain amplitude.

1.6.2

cycle

smallest segment of the force-time, stress-time, strain-time, etc., function that is repeated periodically

1.6.3

cyclic strain hardening exponent

n′

slope of cyclic curve log(σ a) as a function of log(σ_pa)

1.6.4

cyclic strength coefficient

K′

value of stress that intercepts at ε_pa = 1 on a cyclic graph log(σ_a) as a function of log(ε_pa)

1.6.5

cyclic yield strength

σ_y'

0,2% offset yield strength determined on a cyclic stress-strain curve

1.6.6

elastic strain

ε_e

1.6.7

fatigue crack growth rate

da/dN

growth in crack length per force cycle (mm/cycle)

1.6.8

fatigue crack growth threshold

ΔK_th

asymptotic value of ΔK for which da/dN approaches zero

Note 1 to entry: For most materials, the threshold is defined as the stress intensity factor range corresponding to 10⁻⁸ mm/cycle.

1.6.9

fatigue life

N_f

number of applied cycles to achieve a defined failure criterion

1.6.10

fatigue limit

term formerly used for the value of stress amplitude below which a test specimen would be expected to endure an infinite number of stress cycles with a stated probability

1.6.11

fatigue notch factor

K_f

ratio of the fatigue strength of a plain specimen to that of a notched specimen at the same fatigue life

1.6.12

fatigue strength

S

value of stress level at which a specimen would fail at an indicated life

1.6.13

fatigue strength at N cycles

σ_N

value of the stress amplitude at a stated stress ratio under which the specimen would have a life of N cycles

Note 1 to entry: Metals generally do not exhibit a “fatigue limit” or “endurance limit” by itself, that is, a stress below which the metal will endure an infinite number of cycles. Typically, the “plateau(s)” in stress-life curves are referred to as the conventional “fatigue limit(s)” or “endurance limit(s)”, but failures below these levels do occur.

1.6.14

fatigue strength exponent

b

value of slope of curve log(ε_e) as a function of log(2N_f)

1.6.15

fatigue test

test to determine fatigue life, fatigue strength at a given life, etc., by applying repeated forces or strains, or varying forces or strains, to a test piece

1.6.16

force ratio

stress ratio

R

algebraic ratio of the minimum force or stress to maximum force or stress in a cycle

1.6.17

frequency

number of force or strain cycles per unit time applied to the test piece during fatigue testing

1.6.18

high-cycle fatigue test

fatigue test carried out in the region where the stress behaviour is dominant and fatigue life is relatively longer

1.6.19

hysteresis loop

closed curve of the stress-strain response of specimens during one cycle

1.6.20

K -decreasing test

test in which the value of the normalized K -gradient, C , is negative

Note 1 to entry: A K -decreasing test is conducted by reducing the stress intensity factor, either by continuously shedding or by a series of steps, as the crack grows

1.6.21

K -increasing test

test in which the value of C is positive

Note 1 to entry: For the standard specimens, constant force amplitude results in a K -increasing test where the value of C is positive and increasing.

1.6.22

low-cycle fatigue test

fatigue test carried out in the region where the cyclic plastic strain behaviour is dominant and fatigue life is relatively shorter

1.6.23

maximum stress

σ_max, S_max

greatest algebraic value of stress in the stress cycle

1.6.24

mean stress

σ_m, S_m

one-half of the algebraic sum of the maximum stress and minimum stress

1.6.25

mechanical strain

ε_m

strain that is independent of temperature and is associated with the force applied onto the specimen

1.6.26

minimum stress

σ_min, S_min

lowest algebraic value of stress in the stress cycle

1.6.27

normalized K -gradient

C

Note 1 to entry: It is expressed as millimetres to the power minus one.

1.6.28

plastic strain

ε_p

plastic strain component of a controlled strain

1.6.29

S-N curve

curve that is the same as the Wöhler curve, or stress-life curve

1.6.30

strain amplitude

ε_p

one-half of the algebraic difference between the maximum strain and the minimum strain in the strain cycle

1.6.31

strain ratio

R_ε

1.6.32

stress amplitude

σ_a, S_a

one-half of the algebraic difference between the maximum stress and the minimum stress in the stress cycle

1.6.33

stress level

S

intensity of the stress under the conditions of control in the test

1.6.34

stress range

Δσ, ΔS

1.6.35

stress step

d

difference between neighbouring stress levels when conducting the test by the staircase method

1.6.36

thermal strain

ε_th

strain corresponding to the free expansion induced by a change in temperature

1.6.37

thermomechanical fatigue test

TMF

fatigue test under the conditions where cyclic, theoretically uniform temperatures within the test section and strain fields are externally imposed, simultaneously varied and controlled

1.6.38

total strain

S_maxε_tot

change in gauge length divided by the original gauge length

1.6.39

Wöhler curve

curve expressing the relation between stress and fatigue life