MIL-HDBK-17-2F Volume 2,Chapter 1 General Information CHAPTER 1 GENERAL INFORMATION 1.1 INTRODUCTION The standardization of a statistically-based mechanical property data base,procedures used,and overall material guidelines for characterization of composite material systems is recognized as being beneficial to both manufacturers and governmental agencies.It is also recognized that a complete char- acterization of the capabilities of any engineering material system is primarily dependent on the inherent material physical and chemical composition which precede,and are independent of,specific applications. Therefore,at the material system characterization level,the data and guidelines contained in this hand- book are applicable to military and commercial products and provide the technical basis for establishing statistically valid design values acceptable to certificating or procuring agencies. This standardization handbook has been developed and is maintained as a joint effort of the Depart- ment of Defense and the Federal Aviation Administration.It is oriented toward the standardization of methods used to develop and analyze mechanical property data on current and emerging composite ma- terials. 1.2 PURPOSE AND SCOPE OF VOLUME 2 A primary focus of this Handbook is guidance on the selection and use of composite materials.The data collected within this volume are presented to allow initial assessments of material adequacy for a particular application.It provides a common database that will allow significant reductions in the amount of validation data necessary to use the data for design purposes.This handbook cannot be cited as a DoD contractor requirement. This handbook volume provides a standard source of statistically based mechanical property data for current and emerging polymeric matrix composite materials.Physical,chemical,and mechanical values of the composite constituents-the fibers,matrix material,and prepreg-are reported where applicable. Subsequent chapters include data summaries for the various composite systems.Individual chapters focus on particular type of reinforcement fiber.Strength and strain-to-failure properties are reported in terms of mean and A-values and/or B-values.The A and B statistical allowable values are determined by the procedures of Volume 1.Only mean values are reported for stiffnesses.Maximum and minimum data points,and coefficients of variation are reported for all data items The verification of the ability to attain equivalent statistical properties to the required level of risk (probability and confidence)is the responsibility of the user.The verification of the ability of a manufac- turer to attain the same statistical properties should be performed as outlined in Volume 1,Chapter 2. The specific process to leverage the data in this volume is described in Volume 1,Section 2.3.7. The source and context for much of the handbook data sets has historically come from experience with aerospace flight-critical structures.However,all transportation industries (aerospace,ground,rail, and marine),whether commercial or military,as well as other applications including civil infrastructure and general industrial products,will find the handbook useful.Incorporation of additional information related to broader applications is ongoing.Initial input has led to predominantly lamina mechanical properties of prepreg tape and fabric.The range of materials has expanded to cover resin transfer molded and repair materials.The range of properties covered has expanded to laminate mechanicals.Expansion of the ranges of both properties and material forms is expected to continue. Statistically based strength properties are defined for each composite material system over the usable range of environment.The intent is to provide data at the upper and lower limits of the environmental range for a particular material.If intermediate environmental condition data are available,they are in- cluded to assist in defining the relationship over the environmental range.The statistically based strength data can be used as a starting point for establishing structural design allowables when stress and 1-1
MIL-HDBK-17-2F Volume 2, Chapter 1 General Information 1-1 CHAPTER 1 GENERAL INFORMATION 1.1 INTRODUCTION The standardization of a statistically-based mechanical property data base, procedures used, and overall material guidelines for characterization of composite material systems is recognized as being beneficial to both manufacturers and governmental agencies. It is also recognized that a complete characterization of the capabilities of any engineering material system is primarily dependent on the inherent material physical and chemical composition which precede, and are independent of, specific applications. Therefore, at the material system characterization level, the data and guidelines contained in this handbook are applicable to military and commercial products and provide the technical basis for establishing statistically valid design values acceptable to certificating or procuring agencies. This standardization handbook has been developed and is maintained as a joint effort of the Department of Defense and the Federal Aviation Administration. It is oriented toward the standardization of methods used to develop and analyze mechanical property data on current and emerging composite materials. 1.2 PURPOSE AND SCOPE OF VOLUME 2 A primary focus of this Handbook is guidance on the selection and use of composite materials. The data collected within this volume are presented to allow initial assessments of material adequacy for a particular application. It provides a common database that will allow significant reductions in the amount of validation data necessary to use the data for design purposes. This handbook cannot be cited as a DoD contractor requirement. This handbook volume provides a standard source of statistically based mechanical property data for current and emerging polymeric matrix composite materials. Physical, chemical, and mechanical values of the composite constituents - the fibers, matrix material, and prepreg - are reported where applicable. Subsequent chapters include data summaries for the various composite systems. Individual chapters focus on particular type of reinforcement fiber. Strength and strain-to-failure properties are reported in terms of mean and A-values and/or B-values. The A and B statistical allowable values are determined by the procedures of Volume 1. Only mean values are reported for stiffnesses. Maximum and minimum data points, and coefficients of variation are reported for all data items. The verification of the ability to attain equivalent statistical properties to the required level of risk (probability and confidence) is the responsibility of the user. The verification of the ability of a manufacturer to attain the same statistical properties should be performed as outlined in Volume 1, Chapter 2. The specific process to leverage the data in this volume is described in Volume 1, Section 2.3.7. The source and context for much of the handbook data sets has historically come from experience with aerospace flight-critical structures. However, all transportation industries (aerospace, ground, rail, and marine), whether commercial or military, as well as other applications including civil infrastructure and general industrial products, will find the handbook useful. Incorporation of additional information related to broader applications is ongoing. Initial input has led to predominantly lamina mechanical properties of prepreg tape and fabric. The range of materials has expanded to cover resin transfer molded and repair materials. The range of properties covered has expanded to laminate mechanicals. Expansion of the ranges of both properties and material forms is expected to continue. Statistically based strength properties are defined for each composite material system over the usable range of environment. The intent is to provide data at the upper and lower limits of the environmental range for a particular material. If intermediate environmental condition data are available, they are included to assist in defining the relationship over the environmental range. The statistically based strength data can be used as a starting point for establishing structural design allowables when stress and
MIL-HDBK-17-2F Volume 2,Chapter 1 General Information strength analysis capabilities permit lamina and laminate level margin of safety checks.Depending on the application,some structural design allowables will have to be determined empirically at higher testing levels (element,sub-component,full-scale)as they may be dependent on design geometry and philoso- phies.Additional information and properties will be added to this Volume as they become available and are demonstrated to meet the handbook's criteria. All statistical data included herein are based on test specimens only.Unless otherwise noted,test specimen dimensions conform to those specified for the particular test method that is used.Standard test methods are recommended in Volume 1.In Volume 2,data are limited to those obtained from recom- mended in Volume 1.The data contained in this volume may have been provided by more than one source.Where more than one source for data is used for a reported property.the variability of the data from source to source has been reviewed statistically in accordance with Volume 1,Chapters 2 and 8.If the variability has been sufficiently small for the data to be considered from the same population,the data sets are combined and treated as one data set.Where there are reasons for differences among the data sets,both data sets are presented(for example,Volume 2,Section 4.2.8). The designer,manufacturer and all users are responsible for any translation of the data contained herein to other production sites,specimen dimensions,temperature,humidity,and other environmental conditions not specifically identified in this document.Issues not addressed in this document are scale- up effects and the influence of the selected test method on properties.In general,decisions concerning which properties to use for a specific application or design are the responsibility of the user and are out- side the scope of this handbook.MIL-HDBK-17,Volume 3,addresses some of the relevant issues re- garding design usage of the data in this volume.It is the responsibility of the handbook user to meet end use,customer and regulatory requirements. An overview of the material,guidelines for its usage,and details of the statistical and technical analy- sis of the data are provided at the beginning of each section of Chapters 4 through 10.The format of all information in each data set is described in detail in Section 1.4.A more detailed description of fibers and/or matrix materials may be found in Volume 3,Chapter 2. 1.3 ORGANIZATION OF DATA IN HANDBOOK The data in Volume 2 is divided into chapters of fiber properties,resin properties,and composite properties organized by fiber and then resin. 1.3.1 Fiber properties Chapter 2 in Volume 2 will provide data for fiber properties.Sections are to be included for different types of fiber.e.g.,glass fibers and carbon fibers.Fiber properties and methods for obtaining them are discussed in Volume 1,Chapter 3. 1.3.2 Matrix properties Matrix or resin properties will be included in Chapter 3 which will be divided into sections according to the type of resin.For example,Section 3.2 will give data for epoxies and Section 3.3 will provide data for polyester resins.Resin properties and methods for obtaining them are presented in Volume 1,Chapter 4. 1.3.3 Composite properties The remaining chapters of Volume 2 will provide data for prepreg,lamina,laminate,and joint proper- ties.Methods for characterizing materials are discussed in Volume 1,Chapter 5,and properties and defi- nitions for laminae and laminates are presented in Volume 1,Chapter 6.Properties for structural ele- ments are presented in Volume 1,Chapter 7.The statistical methods used in determining these proper- 1-2
MIL-HDBK-17-2F Volume 2, Chapter 1 General Information 1-2 strength analysis capabilities permit lamina and laminate level margin of safety checks. Depending on the application, some structural design allowables will have to be determined empirically at higher testing levels (element, sub-component, full-scale) as they may be dependent on design geometry and philosophies. Additional information and properties will be added to this Volume as they become available and are demonstrated to meet the handbook's criteria. All statistical data included herein are based on test specimens only. Unless otherwise noted, test specimen dimensions conform to those specified for the particular test method that is used. Standard test methods are recommended in Volume 1. In Volume 2, data are limited to those obtained from recommended in Volume 1. The data contained in this volume may have been provided by more than one source. Where more than one source for data is used for a reported property, the variability of the data from source to source has been reviewed statistically in accordance with Volume 1, Chapters 2 and 8. If the variability has been sufficiently small for the data to be considered from the same population, the data sets are combined and treated as one data set. Where there are reasons for differences among the data sets, both data sets are presented (for example, Volume 2, Section 4.2.8). The designer, manufacturer and all users are responsible for any translation of the data contained herein to other production sites, specimen dimensions, temperature, humidity, and other environmental conditions not specifically identified in this document. Issues not addressed in this document are scaleup effects and the influence of the selected test method on properties. In general, decisions concerning which properties to use for a specific application or design are the responsibility of the user and are outside the scope of this handbook. MIL-HDBK-17, Volume 3, addresses some of the relevant issues regarding design usage of the data in this volume. It is the responsibility of the handbook user to meet end use, customer and regulatory requirements. An overview of the material, guidelines for its usage, and details of the statistical and technical analysis of the data are provided at the beginning of each section of Chapters 4 through 10. The format of all information in each data set is described in detail in Section 1.4. A more detailed description of fibers and/or matrix materials may be found in Volume 3, Chapter 2. 1.3 ORGANIZATION OF DATA IN HANDBOOK The data in Volume 2 is divided into chapters of fiber properties, resin properties, and composite properties organized by fiber and then resin. 1.3.1 Fiber properties Chapter 2 in Volume 2 will provide data for fiber properties. Sections are to be included for different types of fiber, e.g., glass fibers and carbon fibers. Fiber properties and methods for obtaining them are discussed in Volume 1, Chapter 3. 1.3.2 Matrix properties Matrix or resin properties will be included in Chapter 3 which will be divided into sections according to the type of resin. For example, Section 3.2 will give data for epoxies and Section 3.3 will provide data for polyester resins. Resin properties and methods for obtaining them are presented in Volume 1, Chapter 4. 1.3.3 Composite properties The remaining chapters of Volume 2 will provide data for prepreg, lamina, laminate, and joint properties. Methods for characterizing materials are discussed in Volume 1, Chapter 5, and properties and definitions for laminae and laminates are presented in Volume 1, Chapter 6. Properties for structural elements are presented in Volume 1, Chapter 7. The statistical methods used in determining these proper-
MIL-HDBK-17-2F Volume 2,Chapter 1 General Information ties are discussed in Volume 1,Chapter 8.There will be individual chapters for each family of composites based on fiber type.For example,Chapter 4 describes carbon fiber composites. 1.4 PRESENTATION OF DATA This section provides information on how the data are presented in this volume,both to help under- stand the data as presented and to ensure the data presentation is consistent.Information enclosed in 's represents data that should be included in a given field.Information that is not applicable or not avail- able is omitted. Each section is titled based on the following information. {Fiber Commercial Name){Filament Count)/(Matrix Commercial Name}{Tape/Weave Type/Weave Style}{Critical Processing Information} Examples of the tape/weave type include unidirectional tape,plain weave,and five-harness satin weave.Weave styles are descriptive codes most commonly used for glass fabrics,such as 7781.Addi- tional information is shown when it is necessary to discriminate between data sets.This includes material information such as glass surface finish or critical processing information,such as bleed or no-bleed.If a warning regarding data documentation is included for the data set,an asterisk follows the section title. Each section contains three types of information(Figure 1.4). The data set description identifies the specific material system,provides selected supplier informa- tion,and discusses any anomalies which appeared during data sets.The summary data tables give an overview of property types and data classes included in the section.The Individual individual data tables provide the details of data analysis.A Data Tables separate individual data table is included for each test type, loading direction,and lay-up in the data set.The following Summary Data describe the content and format for each of these subsec- Tables tions. Data Set 1.4.1 Data set description Description The first page of each section presents general informa- tion. Material Description: FIGURE 1.4 Types of information in Material-[Fiber Commercial Name){Filament Count)/{Ma- each data section. trix Commercial Name}for the material tested. Form-Description of material tested including unidirectional tape or weave type,nominal fiber areal weight,typical cured resin content,typical cured ply thickness,sizing,tackifier or binder(class,form, manufacturer,and common name),and/or scrim fiber class and scrim fabric style as relevant.This infor- mation is specific to the data set that follows it. Processing-Description of processing including information listed under Process Description in Volume 1,Table2.5.6. General Supplier Information:This section presents information often provided by the material supplier. There are no requirements for substantiation of this information. Fiber:Often includes precursor,surface treatment,twist,filament count,typical tensile modulus or modulus family,and typical tensile strength. 1-3
MIL-HDBK-17-2F Volume 2, Chapter 1 General Information 1-3 ties are discussed in Volume 1, Chapter 8. There will be individual chapters for each family of composites based on fiber type. For example, Chapter 4 describes carbon fiber composites. 1.4 PRESENTATION OF DATA This section provides information on how the data are presented in this volume, both to help understand the data as presented and to ensure the data presentation is consistent. Information enclosed in {}’s represents data that should be included in a given field. Information that is not applicable or not available is omitted. Each section is titled based on the following information. {Fiber Commercial Name} {Filament Count}/{Matrix Commercial Name} {Tape/Weave Type/Weave Style} {Critical Processing Information} Examples of the tape/weave type include unidirectional tape, plain weave, and five-harness satin weave. Weave styles are descriptive codes most commonly used for glass fabrics, such as 7781. Additional information is shown when it is necessary to discriminate between data sets. This includes material information such as glass surface finish or critical processing information, such as bleed or no-bleed. If a warning regarding data documentation is included for the data set, an asterisk follows the section title. Each section contains three types of information (Figure 1.4). The data set description identifies the specific material system, provides selected supplier information, and discusses any anomalies which appeared during data sets. The summary data tables give an overview of property types and data classes included in the section. The individual data tables provide the details of data analysis. A separate individual data table is included for each test type, loading direction, and lay-up in the data set. The following describe the content and format for each of these subsections. 1.4.1 Data set description The first page of each section presents general information. Material Description: Material - {Fiber Commercial Name} {Filament Count}/ {Matrix Commercial Name} for the material tested. Form - Description of material tested including unidirectional tape or weave type, nominal fiber areal weight, typical cured resin content, typical cured ply thickness, sizing, tackifier or binder (class, form, manufacturer, and common name), and/or scrim fiber class and scrim fabric style as relevant. This information is specific to the data set that follows it. Processing - Description of processing including information listed under Process Description in Volume 1, Table 2.5.6. General Supplier Information: This section presents information often provided by the material supplier. There are no requirements for substantiation of this information. Fiber: Often includes precursor, surface treatment, twist, filament count, typical tensile modulus or modulus family, and typical tensile strength. Individual Data Tables Individual DataTables Individual Data Tables Summary Data Tables Summary Data Tables Data Set Description FIGURE 1.4 Types of information in each data section
MIL-HDBK-17-2F Volume 2,Chapter 1 General Information Matrix:Often includes resin type,cure temperature family,description of characteristics. Maximum Service Temperature:For dry and wet conditions. Typical Applications:Brief description of applications.May be as generic as "general purpose structural applications"or more specific based on critical characteristics. Data Analysis Summary:This section contains pertinent information from the statistical analysis of the data.If no other information is included in this section,no data analysis. Testing:Often includes information on documented deviations from standard test method. Outliers:Often includes information on the outliers observed,particularly after pooling batches,and their disposition (see Volume 1,Sections 2.5.8 and 2.4.4). Batch Definition:Often includes information on independence of fiber and matrix lots used in the compos- ite batches. Batch-to-Batch Variability and Pooling of Data Sets:Often includes information on decision-making for pooling based on batch-to-batch variability.May also contain information on relative batch behavior,such as one batch consistently providing results different from other batches. Additional Information:For any notes or comments to highlight other concerns by the Secretariat or Data Review working group during analysis and review of the data. Processing Trace:When available,a processing trace will be presented.Included will be the process- ing history based on the specification including ramp rates and relative timing of the application of the various processing parameters. Lay-Up Schematic:When available,a sketch of the processing lay-up will be presented.Included will be bagging,damming,bleeder material,and so on. The remaining pages in each data section represent data analyzed by the Secretariat,evaluated by the Data Review working group,and approved by the Coordination Group.These data are presented in tables that are described in more detail below.Tables in each section are organized in the same order the properties are listed in the summary tables. 1.4.2 Summary tables The format for the first page of summary information is shown in Table 1.4.2(a).Details for different portions of the figure are indexed to descriptions in the text by numbered circles. The first set of information in a data section is a summary table containing information on the ma- terials,processing,etc.The box with a heavy border in the upper right-hand corner identifies the first summary table. [Fiber Class)/{Matrix Class){Nominal FAW)-{Tape/Weave Type} {Fiber)/Matrix) Summary 1-4
MIL-HDBK-17-2F Volume 2, Chapter 1 General Information 1-4 Matrix: Often includes resin type, cure temperature family, description of characteristics. Maximum Service Temperature: For dry and wet conditions. Typical Applications: Brief description of applications. May be as generic as "general purpose structural applications" or more specific based on critical characteristics. Data Analysis Summary: This section contains pertinent information from the statistical analysis of the data. If no other information is included in this section, no data analysis. Testing: Often includes information on documented deviations from standard test method. Outliers: Often includes information on the outliers observed, particularly after pooling batches, and their disposition (see Volume 1, Sections 2.5.8 and 2.4.4). Batch Definition: Often includes information on independence of fiber and matrix lots used in the composite batches. Batch-to-Batch Variability and Pooling of Data Sets: Often includes information on decision-making for pooling based on batch-to-batch variability. May also contain information on relative batch behavior, such as one batch consistently providing results different from other batches. Additional Information: For any notes or comments to highlight other concerns by the Secretariat or Data Review working group during analysis and review of the data. Processing Trace: When available, a processing trace will be presented. Included will be the processing history based on the specification including ramp rates and relative timing of the application of the various processing parameters. Lay-Up Schematic: When available, a sketch of the processing lay-up will be presented. Included will be bagging, damming, bleeder material, and so on. The remaining pages in each data section represent data analyzed by the Secretariat, evaluated by the Data Review working group, and approved by the Coordination Group. These data are presented in tables that are described in more detail below. Tables in each section are organized in the same order the properties are listed in the summary tables. 1.4.2 Summary tables The format for the first page of summary information is shown in Table 1.4.2(a). Details for different portions of the figure are indexed to descriptions in the text by numbered circles. ➊ The first set of information in a data section is a summary table containing information on the materials, processing, etc. The box with a heavy border in the upper right-hand corner identifies the first summary table. {Fiber Class}/{Matrix Class} {Nominal FAW} - {Tape/Weave Type} {Fiber}/{Matrix} Summary
MIL-HDBK-17-2F Volume 2,Chapter 1 General Information This box contains the fiber/matrix class of the material,such as carbon/epoxy,identified using the material system codes in Section 1.5.1.With the fiber and matrix classes is the nominal fiber areal weight and the abbreviated tape/weave type.Abbreviations for tape and weave type include UT(unidirectional tape),PW(plain weave),or nHS(n-harness satin)The material identification is summarized by the fiber and matrix names. 2 Material information is presented for the composite,the preconsolidation form,the fiber,and the matrix.Composite material identification,presented in the Material slot,is the same as the section title. The preconsolidation Form description depends on the form type.For prepregs,the Form de- scription includes (Manufacturer)(Commercial Name)Weave pattern)[Tape/Weave Type}prepreg For prepregged fabric,information such as warp and fill fiber spacing is included when it is avail- able.For RTM and wet fabric lay-up,the Form description includes (Weaver)[Fabric Style if glass)(Weave PatternH(tow/in x tow/in)(Fabric Sizing Identification) {Fabric Sizing Content),{Tackifier)tackifier +[liquid/film)resin If a binder is used,information on the binder replaces information on a tackifier. Fiber identification includes [Manufacturer)[Commercial Name)[Filament Count){Sizing)[Sizing Amount)[Twist)([not]surface treated/surface treatment type).Resin identification is presented as {Manufacturer){Commercial Name). 3 Overall processing information is presented as Reinforcement Application Process (how the fi- ber/preform was put together)followed by Cure Process Type (how the part was cured/molded) from Table 1.4.2(b).Basic processing information for one or more processing steps,including the type of processing step (from Table 1.4.2(b),temperature,pressure,duration,and any other criti- cal parameters,is presented.A more complete description may be provided in graphical form as part of the summary information(see Section 1.4.1). 4 Glass transition temperature under dry and wet conditions is presented with the test method used to obtain these data(See Volume 1,Section 6.6.3).These may be nominal values obtained from the matrix supplier. 5 Any warning for limited data documentation is presented on each page of data presentation.On the first page of the data section,a warning is shown below the material identification block. 6 The block below the material identification block presents various dates relevant to the fabrication and testing of the material.The date of data submittal determines the data documentation re- quirements that were used for the data set(Volume 1,Section 2.5.6)and the date of analysis de- termines the statistical analysis that was used(Volume 1,Section 8.3).Ranges of dates are pre- sented where appropriate,such as for a testing program that lasted several months. 7 Lamina properties are summarized with the class of data provided for each property.The columns of the lamina property summary table define the environmental conditions.The first column con- tains room temperature ambient or dry data.Dry is used only if a drying procedure was used.Am- bient refers to as-fabricated with subsequent storage in an ambient laboratory environment.The remaining columns are ordered from lowest to highest moisture content and within a given mois- ture content,from lowest to highest temperature.If there is enough space,a blank column sepa- rates the room temperature ambient/dry column from the other columns and each moisture condi- tion from the others. 1-5
MIL-HDBK-17-2F Volume 2, Chapter 1 General Information 1-5 This box contains the fiber/matrix class of the material, such as carbon/epoxy, identified using the material system codes in Section 1.5.1. With the fiber and matrix classes is the nominal fiber areal weight and the abbreviated tape/weave type. Abbreviations for tape and weave type include UT (unidirectional tape), PW (plain weave), or nHS (n-harness satin) The material identification is summarized by the fiber and matrix names. ➋ Material information is presented for the composite, the preconsolidation form, the fiber, and the matrix. Composite material identification, presented in the Material slot, is the same as the section title. The preconsolidation Form description depends on the form type. For prepregs, the Form description includes {Manufacturer} {Commercial Name} {Weave pattern} {Tape/Weave Type} prepreg For prepregged fabric, information such as warp and fill fiber spacing is included when it is available. For RTM and wet fabric lay-up, the Form description includes {Weaver} {Fabric Style if glass} {Weave Pattern}{tow/in x tow/in} {Fabric Sizing Identification} {Fabric Sizing Content}, {Tackifier} tackifier + {liquid/film} resin If a binder is used, information on the binder replaces information on a tackifier. Fiber identification includes {Manufacturer} {Commercial Name} {Filament Count} {Sizing} {Sizing Amount} {Twist} {[not] surface treated/surface treatment type}. Resin identification is presented as {Manufacturer} {Commercial Name}. ➌ Overall processing information is presented as Reinforcement Application Process (how the fiber/preform was put together) followed by Cure Process Type (how the part was cured/molded) from Table 1.4.2(b). Basic processing information for one or more processing steps, including the type of processing step (from Table 1.4.2(b), temperature, pressure, duration, and any other critical parameters, is presented. A more complete description may be provided in graphical form as part of the summary information (see Section 1.4.1). ➍ Glass transition temperature under dry and wet conditions is presented with the test method used to obtain these data (See Volume 1, Section 6.6.3). These may be nominal values obtained from the matrix supplier. ➎ Any warning for limited data documentation is presented on each page of data presentation. On the first page of the data section, a warning is shown below the material identification block. ➏ The block below the material identification block presents various dates relevant to the fabrication and testing of the material. The date of data submittal determines the data documentation requirements that were used for the data set (Volume 1, Section 2.5.6) and the date of analysis determines the statistical analysis that was used (Volume 1, Section 8.3). Ranges of dates are presented where appropriate, such as for a testing program that lasted several months. ➐ Lamina properties are summarized with the class of data provided for each property. The columns of the lamina property summary table define the environmental conditions. The first column contains room temperature ambient or dry data. Dry is used only if a drying procedure was used. Ambient refers to as-fabricated with subsequent storage in an ambient laboratory environment. The remaining columns are ordered from lowest to highest moisture content and within a given moisture content, from lowest to highest temperature. If there is enough space, a blank column separates the room temperature ambient/dry column from the other columns and each moisture condition from the others