MMC Coordination Group
CMH-17 MMC Coordinators
The primary purpose of CMH-17 Volume 4 is the standardization of engineering data development methodologies related to characterization testing, data reduction, and data reporting of properties for metal matrix composite materials. In support of this objective CMH-17 Volume 4 publishes properties on composite material systems for which data meeting specific requirements is available. In addition, CMH-17 provides selected guidance on other technical topics related to composites, including material selection, material specification, material processing, design, analysis, quality control, and repair of typical metal matrix composite materials. Thus, CMH-17 is published in three major sections, and serves as a source for the following:
Section 1 - Guidelines: Documents material characterization data development methodology guidelines adaptable to a wide variety of needs, as well as specific requirements to be met by data published in the handbook. Most procuring and certifying agencies prefer, and some may require, that composite material systems used in critical applications either be characterized in accordance with Section 1 guidelines or selected from material systems published in Section 3.
Section 2 - Utilization of Data: This section provides guidance on statistical analysis of metal matrix composite data. In addition, methodologies and recommendations for design, modeling, joining, structural reliability, and repair are given.
Section 3 - Materials Property Data: Provides a repository of potential design data. The documented property summaries for material systems provide data meeting the criteria for any of the two CMH-17 data documentation classes, (screening and fully approved).
Volume 4 of CMH-17 serves as a general reference source for technical information on metal matrix composites, including:
This volume contains guidelines for determining the properties of composite material systems, their constituents, and generic structural elements, including test planning, test matrices, sampling, conditioning, test procedure selection, data reporting, data reduction, statistical analysis, and other related topics. Special attention is given to the statistical treatment and analysis of data. Section 1 contains guidelines for general development of material characterization data as well as specific requirements for publication of metal matrix composite material data in CMH-17.
It must be emphasized that this handbook differentiates between material basis values (material allowables) and design allowable values. Material basis values, being an intrinsic property of a composite material system, are the focus of this handbook. Design allowable values, while often rooted in material basis values, are application dependent, and consider and include specific additional considerations that may further affect the strength or stiffness of the structure. Also, when establishing application design values there may be additional certification or procurement agency requirements that go beyond CMH-17.
Utilization of data
Section 2 provides methodologies and lessons learned for the design, manufacture, analysis, and supportability of composite structures, and for utilization of the material data provided in Section 3 consistent with the guidance provided in Section 1. Topics discussed in Section 2 include materials and processing, quality control, design and analysis, joints, reliability, and supportability.
Material property data
Section 3 contains statistically-based data meeting specific CMH-17 population sampling and data documentation requirements, covering constituents and material systems of general interest. Data published in Section 3 are under the jurisdiction of the Data Review Working Group and are approved by the overall Coordination Group (the CMH-17 Coordination Group and Working Groups are discussed in Section 1.1.5). New material systems will be included and additional material data for existing systems will be added as data become available and are approved.
The material properties in Section 3 are defined over a range of potential use conditions, focusing, when possible, on the upper and lower material environmental limits so that application-specific environments do not limit use of the data. Data at intermediate environmental conditions, when available, provide additional definition of the relation between material response and environment.
While the process of establishing structural design values for specific applications can begin with the data contained in Section 3, most applications require collection of additional data, especially if there are requirements for data from the laminate or higher structural complexity levels (structural complexity level is discussed in 188.8.131.52). Also, the ability to manufacture material equivalent to that from which the data in Section 3 were obtained typically must be proven to the procuring or certifying agency, which usually involves limited testing and data comparison. The details of such an evaluation remain at the discretion of the procuring or certifying agency.
Second release of Volume 4 will be available for purchase shortly from ASTM
© 2009 Materials Sciences Corporation.