ASTM D5592-94(2002)e1
(Guide)Standard Guide for Material Properties Needed in Engineering Design Using Plastics
Standard Guide for Material Properties Needed in Engineering Design Using Plastics
SIGNIFICANCE AND USE
This guide is intended to serve as a reference to the plastics community for material properties needed in engineering design.
Product datasheets or product literature typically report single-point values at ambient conditions and hence, by their very nature, are inadequate for engineering design and structural analysis of a component or system. A detailed property profile for the particular grade chosen for a given part not only enhances the confidence of the design engineer by allowing a more realistic assessment of the material under close-to-actual service environments but also may avoid premature failure of the designed component and potential liability litigation later. Additionally, it would also eliminate use of larger “design safety factors” that result in “overengineering” or “overdesign.” Not only is such overdesign unwarranted, but it adds to the total part cost, resulting in a good example of ineffective design with plastics and a prime target for substitution by other materials.
One of the problems faced by design engineers is access to comparable data among similar products from different material suppliers because of the lack of standardized reporting format in the plastics industry. ISO 10350.1, 11403-1, and 11403-2 are intended to address the comparability of data issue only as far as single-point and multipoint data for material selection. This guide attempts to serve as a means to standardize the format to report comparable data for engineering design. It is essential that incorporating standardized test specimen geometry and specific test conditions as recommended in Guide D 1999, Practice D 3641, or ISO 3167 and 294-1 are an integral part of the data generation.
SCOPE
1.1 This guide covers the essential material properties needed for designing with plastics. Its purpose is to raise the awareness of the plastics community regarding the specific considerations involved in using the appropriate material properties in design calculations.
1.2 This guide is intended only as a convenient resource for engineering design. It should be noted that the specific operating conditions (temperature, applied stress or strain, environment, etc. and corresponding duration of such exposures) could vary significantly from one application to another. It is, therefore, the responsibility of the user to perform any pertinent tests under actual conditions of use to determine the suitability of the material in the intended application.
1.3 The applicable ISO and ASTM standard methods for the relevant material properties are listed in this guide for the benefit of design engineers.
1.4 It should be noted that for some of the desired properties, no ASTM or ISO standards exist. These include pvT data, no-flow temperature, ejection temperature, and fatigue in tension. In these instances, relying on available test methods is suggested.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1—There is no similar or equivalent ISO standard.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
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Designation:D5592–94 (Reapproved 2002)
Standard Guide for
Material Properties Needed in Engineering Design Using
Plastics
This standard is issued under the fixed designation D5592; 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 (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Editorially corrected items in the Referenced Documents section, as well as made minor editorial corrections in
August 2002.
INTRODUCTION
Plastics are increasingly being used in durable applications as structural components on a basis
comparable with traditional materials such as steels and aluminum, as well as high performance
composite systems. Unlike many consumer-goods applications, where plastics typically serve as
enclosures, these durables applications primarily involve load-bearing components exposed to rather
broad varying operating environments over the life cycle of the product. This necessitates access to
material property profiles over a wide range of conditions, rather than typical values reported at room
temperature.Inordertodesigneffectivelywithplastics,thedesignermusttakeintoaccounttheeffects
of time, temperature, rate, and environment on the performance of plastics, and the consequences of
failure.
1. Scope* responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This guide covers the essential material properties
bility of regulatory limitations prior to use.
needed for designing with plastics. Its purpose is to raise the
awareness of the plastics community regarding the specific
NOTE 1—There is no similar or equivalent ISO standard.
considerations involved in using the appropriate material
2. Referenced Documents
properties in design calculations.
1.2 This guide is intended only as a convenient resource for
2.1 ASTM Standards:
engineering design. It should be noted that the specific oper-
D543 Practices for Evaluating the Resistance of Plastics to
ating conditions (temperature, applied stress or strain, environ-
Chemical Reagents
ment,etc.andcorrespondingdurationofsuchexposures)could
D638 Test Method for Tensile Properties of Plastics
vary significantly from one application to another. It is,
D671 Test Method for Flexural Fatigue of Plastics by
therefore, the responsibility of the user to perform any perti-
Constant-Amplitude-of-Force
nent tests under actual conditions of use to determine the
D695 Test Method for Compressive Properties of Rigid
suitability of the material in the intended application.
Plastics
1.3 TheapplicableISOandASTMstandardmethodsforthe
D883 Terminology Relating to Plastics
relevant material properties are listed in this guide for the
D1435 Practice for Outdoor Weathering of Plastics
benefit of design engineers.
D1894 Test Method for Static and Kinetic Coefficients of
1.4 It should be noted that for some of the desired proper-
Friction of Plastic Film and Sheeting
ties, noASTM or ISO standards exist. These include pvT data,
D1999 Guide for Selection of Specimens and Test Param-
no-flow temperature, ejection temperature, and fatigue in
eters from ISO/IEC Standards
tension. In these instances, relying on available test methods is
D2565 Practice for Xenon-Arc Exposure of Plastics In-
suggested.
tended for Outdoor Applications
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This guide is under the jurisdiction of ASTM Committee D20 on Plastics and Standards volume information, refer to the standard’s Document Summary page on
is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. the ASTM website.
Current edition approved September 15, 1994. Published November 1994. DOI: Withdrawn. The last approved version of this historical standard is referenced
10.1520/D5592-94R02E01. on www.astm.org.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5592–94 (2002)
D2990 Test Methods for Tensile, Compressive, and Flex- Light Sources—Part 1: General Guidance
ural Creep and Creep-Rupture of Plastics
ISO 4892-2 Plastics—Methods of Exposure to Laboratory
D2991 Practice for Testing Stress-Relaxation of Plastics
Light Sources—Part 2: Xenon Arc Sources
D3045 Practice for Heat Aging of Plastics Without Load
ISO 6721-2 Plastics—Determination of Dynamic Mechani-
D3123 Test Method for Spiral Flow of Low-Pressure Ther-
cal Properties—Part 2: Torsion Pendulum
mosetting Molding Compounds
ISO 8295 Plastics—Film and Sheeting—Determination of
D3417 Test Method for Enthalpies of Fusion and Crystal-
the Coefficients of Friction
lization of Polymers by Differential Scanning Calorimetry
ISO 10350.1 Plastics—Acquisition and Presentation of
(DSC)
Comparable Single-Point Data— Part 1: Moulding Mate-
D3418 Test Method for Transition Temperatures and En-
rials
thalpies of Fusion and Crystallization of Polymers by
ISO 11403-1 Plastics—Acquisition and Presentation of
Differential Scanning Calorimetry
Comparable Multipoint Data—Part 1: Mechanical Prop-
D3641 Practice for Injection Molding Test Specimens of
erties
Thermoplastic Molding and Extrusion Materials
ISO 11403-2 Plastics—Acquisition and Presentation of
D3835 Test Method for Determination of Properties of
Comparable Multipoint Data—Part 2: Thermal and Pro-
Polymeric Materials by Means of a Capillary Rheometer
cessing Properties
D4473 Test Method for Plastics: Dynamic Mechanical
ISO 11443 Plastics—Determination of the Fluidity of Plas-
Properties: Cure Behavior
tics Using Capillary and Slit-Die Rheometers
D5045 Test Methods for Plane-Strain Fracture Toughness
and Strain Energy Release Rate of Plastic Materials
3. Terminology
D5279 Test Method for Plastics: Dynamic Mechanical
3.1 Definitions:
Properties: In Torsion
3.1.1 aging—the effect on materials of exposure to an
E6 TerminologyRelatingtoMethodsofMechanicalTesting
environment for an interval of time (see Terminology D883).
E228 Test Method for Linear Thermal Expansion of Solid
3.1.2 coeffıcient of friction—a measure of the resistance to
Materials With a Push-Rod Dilatometer
sliding of one surface in contact with another surface.
E1150 Definitions of Terms Relating to Fatigue
3.1.3 coeffıcient of linear thermal expansion—the change in
2.2 ISO Standards:
linear dimension per unit of original length of a material for a
ISO 175 Plastics—Determination of the Effects of Immer-
unit change in temperature.
sion in Liquid Chemicals
3.1.4 compressive strength—the compressive stress that a
ISO 294-1 Plastics—Injection Moulding of Test Specimens
material is capable of sustaining. In the case of a material that
of Thermoplastic Materials—General Principles, and
does not fail in compression by a shattering fracture, the value
Moulding of Multipurpose and Bar Test Specimens
for compressive strength is an arbitrary value depending upon
ISO 294-4 Plastics—Injection molding of Test Specimens
the degree of distortion that is regarded as indicating complete
of Thermoplastic Materials - Determination of Moulding
failure of the material (modified from Terminology E6).
Shrinkage
3.1.5 creep—the time-dependent increase in strain in re-
ISO 527-1 Plastics—Determination of Tensile Properties—
sponse to applied stress (modified from Terminology E6).
Part 1: General Principles
3.1.6 creep modulus—the ratio of initial applied stress to
ISO 527-2 Plastics—Determination of Tensile Properties—
creep strain (see Test Method D2990).
Part 2: Test Conditions for Moulding and Extrusion
3.1.7 creep rupture stress—stress to produce material fail-
Plastics
ure corresponding to a fixed time to rupture (modified from
ISO 527-4 Plastics—Determination of Tensile Properties—
Test Method D2990).
Part 4:Test Conditions for Isotropic and Orthotropic Fibre
3.1.8 critical stress intensity factor—toughness parameter
Reinforced Plastic Composites
indicative of the resistance of a material to fracture at fracture
ISO 604 Plastics—Determination of Compressive Proper-
initiation (see Test Method D5045).
ties
3.1.9 engineering stress—stress based on initial cross sec-
ISO 899-1 Plastics—Determination of Creep Behaviour -
tional area of the specimen.
Tensile Creep
3.1.10 fatigue—the process of progressive localized perma-
ISO 899-2 Plastics—Determination of Creep Behaviour -
nent deleterious change or loss of properties occurring in a
Flexural Creep by Three-Point Loading
material subjected to cyclic loading conditions (modified from
ISO 2578 Plastics—Determination of Time-Temperature
Definitions E1150).
Limits After Prolonged Exposure to Heat
3.1.11 Poisson’s ratio—the absolute value of the ratio of
ISO 3167 Plastics—Multipurpose Test Specimens
transverse strain to the corresponding axial strain resulting
ISO4607 Plastics—MethodsofExposuretoNaturalWeath-
from uniformly distributed axial stress below the proportional
ering
limit of the material (see Terminology D883).
ISO 4892-1 Plastics—Methods of Exposure to Laboratory
3.1.12 proportional limit—the greatest stress that a material
is capable of sustaining without any deviation from propor-
tionality of stress to strain (Hooke’s law) (see Test Method
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. D638).
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D5592–94 (2002)
3.1.13 PV limit—the limiting combination of pressure and mended in Guide D1999, Practice D3641,or ISO 3167 and
velocity that will cause failure of any polymer rubbing against 294-1 are an integral part of the data generation.
another surface without lubrication at a specific ambient
temperature and tested in a specific geometry. 5. Material Properties in Engineering Design
3.1.14 secant modulus—the ratio of engineering stress to
5.1 Finite element analysis is an integral part of computer
corresponding strain at a designated strain point on the
aided design/engineering (CAD/CAE). It serves as a powerful
stress-strain curve (see Test Method D638).
tool for design engineers in performing engineering analysis of
3.1.15 shear modulus—the quotient of the shearing stress
plastics components to predict the performance. The material
and the resulting angular deformation of the test specimen
data inputs required for carrying out these analyses essentially
measured in the range of small recoverable deformations (see
constitute the minimum data needed in engineering design.
ISO 6721-2).
5.2 The material properties essential in engineering design
3.1.16 shear strength—the maximum shear stress that a
can be grouped into three main categories; (1) properties
material is capable of sustaining. Shear strength is calculated
essential for structural analysis, (2) properties essential for
from the maximum load during a shear or torsion test and is
assessing manufacturability, and (3) properties essential for
based on the original dimensions of the cross section of the
evaluating assembly. The properties essential for structural
specimen (see Terminology E6).
analysis are employed in assessing the structural integrity of
3.1.17 tensile modulus—the ratio of engineering stress to
the designed part over its useful life or in determining the
corresponding strain below the proportional limit of a material
required geometry of the part to ensure structural integrity.The
in tension (modified from Test Method D638).
properties essential for assessing manufacturability are em-
3.1.18 tensile stress at break—thetensilestresssustainedby
ployed in simulating the part filling/post filling steps to
the material at break (modified from Test Method D638).
optimize processing conditions and for predictions of dimen-
3.1.19 tensile stress at yield—the tensile stress sustained by
sional stability of the manufactured part. The properties essen-
the material at the yield point (modified from Test Method
tial for assembly considerations are employed in evaluating the
D638).
ability to join/assemble the component parts.
3.1.20 warpage—distortion caused by non-uniform change
5.3 As functional requirements are often specific to each
of internal stresses (D883).
application, the material properties essential for structural
3.1.21 yield point—the first point on the stress-strain curve
analysis can be classified into two categories—those that are
at which an increase in strain occurs without an increase in
somewhat application specific and those that are not.
stress (see Test Method D638).
5.4 Whether the individual property is application-specific
4. Significance and Use or not, certain properties are directly employed in design
calculations while others are employed more or less for
4.1 This guide is intended to serve as a reference to the
verification of the design limits. For example, although parts
plastics community for material properties needed in engineer-
may fail in service under multi-axial impact loading condi-
ing design.
tions, the impact energy data can be used only in design
4.2 Product datasheets or product literature typically report
verification, at best.Additional examples of properties that are
single-point values at ambient conditions and hence, by their
usefulonlyfordesignverificationincludefatigue(S-N)curves,
very nature, are inadequate for engineering design and struc-
wear factor, PV limit, retention of properties following expo-
tural analysis of a component or system. A detailed property
sure to chemicals and solvents, and accelerated aging or UV
profile for the particular grade chosen for a given part not only
exposure/outdoor weathering.
enhances the confidence of the design engineer by allowing a
5.5 Almost all structural design calculations fall under one
more realistic assessment of the material under close-to-actual
ofthefollowingtypesofanalysisorsomecombinationthereof:
service environments but also may avoid premature failure of
beam or plate; pipe; snap fits, pressfits, threads, bearing, bolts;
the designed component and potential liability litigation later.
or buckling. The properties needed for each of these design
Additionally, it would also eliminate use of larger “design
calculations are summarized in Table 1.
safety factors” that result in “overengineering” or “overde-
5.6 In plate and beam analyses, flexural modulus is often
sign.” Not only is such overdesign unwarranted, but it adds to
used in determining the beam deflection or s
...
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