ASTM D6874-20

Standard Test Methods for Nondestructive Evaluation of the Stiffness of Wood and Wood-Based Materials Using Transverse Vibration or Stress Wave Propagation

SIGNIFICANCE AND USE
5.1 The dynamic modulus of elasticity provided by these test methods is a fundamental property for the configuration tested.  
5.1.1 The rapidity and ease of application of these test methods facilitate their use as a substitute for static measurements.  
5.1.2 Dynamic modulus of elasticity is often used for surveys, for segregation of lumber for test purposes, for quality assessment of engineered wood products, and to provide indication of environmental or processing effect.  
5.2 The modulus of elasticity, whether measured statically or dynamically, is often a useful predictor variable to suggest or explain property relationships.  
5.3 Results from these test methods can be related to other measurements of modulus of elasticity, such as static methods (see Annex A1 and Appendix X4).  
5.4 These methods use calculations that assume specimens are prismatic in cross-section and are uniform in modulus of elasticity and density.  
5.4.1 As a result of the above assumptions, the obtained values of modulus of elasticity are dependent on how the specimen is stressed (see Commentary).  
5.4.2 Transverse vibration and longitudinal stress wave modulus of elasticity are correlated but not necessarily equal.  
5.4.3 These methods provide a means to establish a model to predict one dynamic modulus of elasticity from another dynamic method or a static method (i.e., D198, D4761, etc.).  
5.4.4 The methods can also be used to estimate the Class I or Class II modulus of elasticity from the Class III method, or the Class I from the Class II method.  
5.5 Testing specified to be undertaken in accordance with this Method shall include any requirements regarding the following for each Class:  
5.5.1 Grades and/or species permitted to be combined to form the training and validation test sample.  
5.5.2 Selection and positioning of manufacturing or growth characteristics to be included or permitted in the test sample.  
5.5.3 Moisture content conditioning undertaken prior t...
SCOPE
1.1 These test methods cover the non-destructive determination of the following dynamic properties of wood and wood-based materials from measuring the fundamental frequency of vibration:  
1.1.1 Flexural stiffness and apparent modulus of elasticity (Etv) properties using simply or freely supported beam transverse vibration in the vertical direction, and  
1.1.2 Axial stiffness and apparent longitudinal modulus of elasticity (Esw) using stress wave propagation time in the longitudinal direction.  
1.2 The test methods can be used for a broad range of wood-based materials and products ranging from logs, timbers, lumber, and engineered wood products.  
1.2.1 The two flexural methods can be applied to flexural products such as glulam beams and I-joists.  
1.2.2 The longitudinal stress wave methods are limited to solid wood and homogeneous grade glulam (e.g., columns but not products with distinct subcomponents such as wood I-joists).  
1.3 The standard recognizes three implementation classes for each of these test methods.  
1.3.1 Class I—Defines the fundamental method to achieve the highest degree of repeatability and reproducibility that can be achieved under laboratory conditions.
Note 1: Testing should follow Class I methods to develop training and validation data sets for method conversion models (see Annex A2).  
1.3.2 Class II—Method with permitted modifications to the Class I method that can be used to address practical issues found in the field, and where practical deviations from the Class I protocol are known and their effects can be accounted.
Note 2: Practical deviations include, for example, environmental and test boundary conditions. Class II methods allow for corrections to test results to account for quantifiable effect such as machine frame deflections.  
1.3.3 Class III—Method permitting the broadest range of application, with permitted modifications to suit a wider range of practical needs wi...

General Information

• Status: Historical
• Publication Date: 14-Apr-2020
• ICS: 19.100 - Non-destructive testing
• Technical Committee: D07 - Wood
• Drafting Committee: D07.01 - Fundamental Test Methods and Properties

Standards Content (Sample)

Designation: D6874 − 20
Standard Test Methods for
Nondestructive Evaluation of the Stiffness of Wood and
Wood-Based Materials Using Transverse Vibration or Stress
1
Wave Propagation
This standard is issued under the fixed designation D6874; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Nondestructive testing methods are used to determine the physical and mechanical properties of
wood and wood-based materials. These test methods help ensure structural performance of products
manufactured from a variety of wood species and quality levels of raw materials. These test methods
also assist in evaluating the influence of environmental conditions on product performance.
Dynamic test methods based on the transverse vibration of a simply or freely supported beam, or
the propagation of a longitudinal stress wave are methods used to nondestructively evaluate
wood-based materials. These methods yield results comparable to traditional static test methods,
permitting standardization of results, interchange and correlation of data, and establishment of a
cumulative body of information on wood species and products of the world.
1. Scope 1.3.1 Class I—Defines the fundamental method to achieve
the highest degree of repeatability and reproducibility that can
1.1 These test methods cover the non-destructive determi-
be achieved under laboratory conditions.
nation of the following dynamic properties of wood and
wood-based materials from measuring the fundamental fre-
NOTE1—TestingshouldfollowClassImethodstodeveloptrainingand
validation data sets for method conversion models (see Annex A2).
quency of vibration:
1.1.1 Flexural stiffness and apparent modulus of elasticity
1.3.2 Class II—Method with permitted modifications to the
(E ) properties using simply or freely supported beam trans-
tv
Class I method that can be used to address practical issues
verse vibration in the vertical direction, and
found in the field, and where practical deviations from the
1.1.2 Axial stiffness and apparent longitudinal modulus of
Class I protocol are known and their effects can be accounted.
elasticity (E ) using stress wave propagation time in the
sw
NOTE 2—Practical deviations include, for example, environmental and
longitudinal direction.
test boundary conditions. Class II methods allow for corrections to test
1.2 The test methods can be used for a broad range of
results to account for quantifiable effect such as machine frame deflec-
tions.
wood-basedmaterialsandproductsrangingfromlogs,timbers,
lumber, and engineered wood products.
1.3.3 Class III—Method permitting the broadest range of
1.2.1 The two flexural methods can be applied to flexural
application, with permitted modifications to suit a wider range
products such as glulam beams and I-joists.
of practical needs with an emphasis on repeatability.
1.2.2 The longitudinal stress wave methods are limited to
NOTE 3—Online testing machines implemented to grade/sort lumber
solid wood and homogeneous grade glulam (e.g., columns but
may be treated as Class III.
not products with distinct subcomponents such as wood
1.4 The standard provides guidance for developing a model
I-joists).
for estimating a non-destructive test method result (e.g., static
1.3 The standard recognizes three implementation classes
modulus of elasticity obtained in accordance with Test Meth-
for each of these test methods.
ods D198) from another non-destructive test method result
(e.g., dynamic longitudinal modulus of elasticity from mea-
1
surement of longitudinal stress wave propagation time).
These test methods are under the jurisdiction of ASTM Committee D07 on
WoodandisthedirectresponsibilityofSubcommitteeD07.01onFundamentalTest
1.4.1 The standard covers only models developed from test
Methods and Properties.
data obtained directly from non-destructively testing a repre-
Current edition approved April 15, 2020. Published October 2020. Originally
sentative sample using one test method, and retesting the same
approved in 2003. Last previous edition approved in 2012 as D6874–12. DOI:
10.1520/D6874-20. sample following a second test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D6874 − 20
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1.4.2 Results used for model development shall not be 2.2 ISO Standards:
estimated from a model. ISO7626⁄1Mechanical vibration and shock—Experimental
determination of mechanical mobility—Part 1: Basic
1.5 Thevaluesstatedininch-poundunitsaretoberegarded
terms and definitions, and transducer specifications
as standard. The values given in parentheses are mathematical
ISO 7625/5Vibration and shock—Experimental determina-
conversions to SI units that are pr
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6874 − 12 D6874 − 20
Standard Test Methods for
Nondestructive Evaluation of Wood-Based Flexural
Members the Stiffness of Wood and Wood-Based Materials
1
Using Transverse Vibration or Stress Wave Propagation
This standard is issued under the fixed designation D6874; 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.
INTRODUCTION
Nondestructive testing methods are used to determine the physical and mechanical properties of
wood and wood-based materials. These test methods help ensure structural performance of products
manufactured from a variety of wood species and quality levels of raw materials. These test methods
also assist in evaluating the influence of environmental conditions on product performance.
TheseDynamic test methods for based on the transverse vibration nondestructive testing of
wood-based materials adopt methods used by various testing and research organizations. These test
methods will of a simply or freely supported beam, or the propagation of a longitudinal stress wave
are methods used to nondestructively evaluate wood-based materials. These methods yield results
comparable to traditional static test methods, permitting standardization of results, interchange and
correlation of data, and establishment of a cumulative body of information on wood species and
products of the world.
1. Scope
1.1 These test methods cover the determination of the flexural stiffness and modulus of elasticity (E) properties of wood-based
materials by nondestructive testing using transverse vibration in the vertical direction.
1.2 The test methods are limited to specimens having solid, rectangular sections.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 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.
2. Referenced Documents
2
2.1 ASTM Standards:
1
These test methods are under the jurisdiction of ASTM Committee D07 on Wood and is the direct responsibility of Subcommittee D07.01 on Fundamental Test Methods
and Properties.
Current edition approved Oct. 1, 2012April 15, 2020. Published October 2012October 2020. Originally approved in 2003. Last previous edition approved in 20092012
ɛ1
as D6874 – 03D6874 – 12.(2009 ). DOI: 10.1520/D6874-12.10.1520/D6874-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D6874 − 20
FIG. 1 Mode Shape of Simply Supported Beam Under Transverse Vibration in the Fundamental Mode
D9 Terminology Relating to Wood and Wood-Based Products
D198 Test Methods of Static Tests of Lumber in Structural Sizes
D1990 Practice for Establishing Allowable Properties for Visually-Graded Dimension Lumber from In-Grade Tests of Full-Size
Specimens
D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products
D4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Based Materials
D4761 Test Methods for Mechanical Properties of Lumber and Wood-Based Structural Materials
D7438 Practice for Field Calibration and Application of Hand-Held Moisture Meters
E4 Practices for Force Verification of Testing Machines
3
E1267 Guide for Astm Standard Specification Quality Statements (Withdrawn 1996)
2.2 Other Standard:
ISO 7626 ⁄1 Vibration and Shock-Experimental Determination of Mechanical Mobility—Part 1: Basic Definitions and
4
Transducers
3. Terminology
3.1 Definitions—See Terminology D9 and Test Methods D198.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 calibration—the determination of the relationship between the response of standardized instrumentation to properties of
reference material, determined by a st
...