Description / Abstract:
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
2.3.1.7).
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.