ASTM D7290-06(2011)
(Practice)Standard Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications
Standard Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications
SIGNIFICANCE AND USE
This practice covers the procedures for computing material property characteristic values for polymeric composite materials intended for use in civil engineering structural applications. A characteristic value represents a statistical lower bound on the material property structural member resistance factors for civil engineering design codes for composite structures.
This practice may be used to obtain characteristic values for stiffness and strength properties of composite materials obtained from measurements using applicable test methods.
SCOPE
1.1 This practice covers the procedures for computing characteristic values of material properties of polymeric composite materials intended for use in civil engineering structural applications. The characteristic value is a statistically-based material property representing the 80 % lower confidence bound on the 5th-percentile value of a specified population. Characteristic values determined using this standard practice can be used to calculate structural member resistance values in design codes for composite civil engineering structures and for establishing limits upon which qualification and acceptance criteria can be based.
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.
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Designation: D7290 − 06 (Reapproved 2011)
Standard Practice for
Evaluating Material Property Characteristic Values for
Polymeric Composites for Civil Engineering Structural
Applications
This standard is issued under the fixed designation D7290; 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.
1. Scope E178 Practice for Dealing With Outlying Observations
E456 Terminology Relating to Quality and Statistics
1.1 This practice covers the procedures for computing
2.2 Other Document:
characteristic values of material properties of polymeric com-
MIL-Handbook-17 Polymer Matrix Composites, Volume 1,
posite materials intended for use in civil engineering structural
Revision F
applications. The characteristic value is a statistically-based
material property representing the 80 % lower confidence
3. Terminology
bound on the 5th-percentile value of a specified population.
3.1 Definitions—Terminology D3878 defines terms relating
Characteristic values determined using this standard practice
to high-modulus fibers and their composites. Terminology
can be used to calculate structural member resistance values in
D883definestermsrelatingtoplastics.TerminologyE6defines
design codes for composite civil engineering structures and for
termsrelatingtomechanicaltesting.TerminologyE456defines
establishing limits upon which qualification and acceptance
terms relating to statistics. In the event of a conflict between
criteria can be based.
terms, Terminology D3878 shall have precedence over the
1.2 This standard does not purport to address all of the
other documents.
safety concerns, if any, associated with its use. It is the
3.2 Definitions of Terms Specific to This Standard:
responsibility of the user of this standard to establish appro-
3.2.1 characteristic value—a statistically-based material
priate safety and health practices and determine the applica-
property representing the 80 % lower confidence bound on the
bility of regulatory limitations prior to use.
5th-percentile value of a specified population. The character-
2. Referenced Documents
istic value accounts for statistical uncertainty due to a finite
2 sample size.
2.1 ASTM Standards:
3.2.1.1 Discussion—The 80 % confidence bound and 5th-
D883 Terminology Relating to Plastics
percentile levels were selected so that composite material
D3878 Terminology for Composite Materials
characteristic values will produce resistance factors for Load
D5055 Specification for Establishing and Monitoring Struc-
and Resistance Factor Design similar to those for other civil
tural Capacities of Prefabricated Wood I-Joists
engineering materials (see Refs 1 and 2).
D5457 Specification for Computing Reference Resistance of
3.2.1.2 Discussion—The term “characteristic value” is
Wood-Based Materials and Structural Connections for
analogous to the term “basis value” used in the aerospace
Load and Resistance Factor Design
industry where A- and B-basis values are defined as the 95 %
D5574 Test Methods for EstablishingAllowable Mechanical
lower confidence bound on the lower 1 % and 10 % values of
Properties of Wood-Bonding Adhesives for Design of
a population, respectively.
Structural Joints
3.2.2 data confidence factor, Ω—a factor that is used to
E6 Terminology Relating to Methods of Mechanical Testing
adjustthesamplenominalvalueforuncertaintyassociatedwith
finite sample size.
This practice is under the jurisdiction ofASTM Committee D30 on Composite
3.2.3 nominal value—the 5th percentile value of the data
Materials and is the direct responsibility of Subcommittee D30.10 on Composites
represented by a probability density function.
for Civil Structures.
Current edition approved Aug. 1, 2011. Published December 2011. Originally
approved in 2006. Last previous edition approved in 2006 as D7290–06. DOI:
10.1520/D7290-06R11. AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.access.gpo.gov.
Standards volume information, refer to the standard’s Document Summary page on The boldface numbers in parentheses refer to the list of references at the end of
the ASTM website. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7290 − 06 (2011)
3.2.4 outlier—an outlying observation, or “outlier,” is one deviation, is too large to be due to chance.This method detects
that deviates significantly from other observations in the one outlier at a time; hence the significance level pertains to a
sample in which it occurs. single decision.
NOTE 2—Practice E178 provides several methods for statistically
4. Significance and Use
analyzing a dataset for outliers. The MNR method is used here because it
4.1 This practice covers the procedures for computing
is a simple method that is unlikely to be miscalculated, misinterpreted or
materialpropertycharacteristicvaluesforpolymericcomposite
misapplied.
materials intended for use in civil engineering structural
NOTE 3—An outlying observation may be an extreme manifestation of
the random variability of the material property value. For such a case, the
applications. A characteristic value represents a statistical
value should be retained and treated as any other observation in the
lower bound on the material property structural member
sample. However, the outlying observation may be the result of a gross
resistance factors for civil engineering design codes for com-
deviation from prescribed experimental procedure or an error in calculat-
posite structures.
ing or recording the numerical value of the data point in question. When
the experimentalist can document a gross deviation from the prescribed
4.2 Thispracticemaybeusedtoobtaincharacteristicvalues
experimental procedure, the outlying observation may be discarded,
for stiffness and strength properties of composite materials
unless the observation can be corrected in a rational manner.
obtained from measurements using applicable test methods.
6.2.1 Outlier Criteria for Single Samples—For a sample of
5. Sampling
size n, arrange the data values {x , x , x , .x } in order of
1 2 3 n
increasing magnitude with x being the largest value. Calculate
5.1 Samples selected for analysis shall be representative of n
the MNR statistic as the maximum absolute deviation from the
the material property population for which the characteristic
sample mean divided by the sample standard deviation:
values are to be calculated.
x 2 x¯
5.2 The minimum number of samples shall be specified in ? i ?
MNR 5 max (3)
S D
s
design codes that reference this standard. n21
NOTE 1—Section 5.3.1 of the building code requirements for structural
6.2.1.1 Calculate the critical MNR value, CV, based on a
concrete (ACI 318-05) requires at least 30 samples to determine the
5 % significance level using the following approximation:
standard deviation of concrete compressive strength for a new batch plant
but allows a reduction to a minimum of 15 samples, provided that a
modification factor is used to increase the standard deviation if less than
CV' 2 2 (4)
S D
30 samples are used (Ref 3). For wood, Specification D5457 requires a =
5 n
minimum of 30 samples for computing the reference resistance of wood
based materials and structural connections for Load and Resistance Factor
6.2.1.2 Therearenooutliersinthesampleofobservationsif
Design, and states that extreme care must be taken during sampling to
the calculated MNR statistic is smaller than the critical value
ensure a representative sample for sample sizes less than 60. The bending
CV, that is MNR ≤ CV.Ifthe MNR statistic is found to be
capacity of wood I-joists can be determined either by analysis or
greater than the critical value, then th
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