COMPOSITE MATERIALS HANDBOOK VOLUME 2
|Publication Date:||1 March 2012|
PURPOSE AND SCOPE OF VOLUME 2
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 elastic properties. Maximum and minimum data values 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. A specific process to demonstrate equivalency of 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, repair materials, and multi-directional laminate properties.
The statistically based strength data can be used as a starting point for establishing structural design allowables. 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 specific manufacturing process. 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. In Volume 2, data are limited to those obtained from recommended test methods 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 188.8.131.52).
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 2 through 5. The format of all information in each data set is described in detail in Section 1.5. A more detailed description of fibers and/or matrix materials may be found in Volume 3, Chapter 2.
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 outside the scope of this handbook. CMH-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.