ASTM D8335-20

4.1 This guide provides the recommended data elements for the identification of fiber-reinforced composite materials and the information which is considered essential to uniquely describe a fiber, filler, or core material.

4.2 The intent of this guide is to provide sufficient detail that values are known for the material parameters that may influence test results or material property values.

4.3 This guide is for material identification and description only. It does not include the recommended data elements for mechanical test data or other specific types of test data. Such items are covered by separate formats to be referenced in material specifications or other test standards.

4.4 Composite materials are defined as two or more materials that are combined on a macroscale. There is a gray area between composites and other material classes. Two examples of this gray area between polymer matrix composites and plastics are toughened polystyrene and liquid crystal polymer. Appendix X1 contains a table, which provides guidelines for distinguishing between reinforced polymers and polymer matrix composites.

4.5 Composite materials consist of a matrix phase and one or more discrete reinforcements. Reinforcements may be interpreted broadly to include any macroscale second material, including fibers, particulates, precipitated particles, or structured domains of the parent material. The reinforcements covered in this guide include fibers and such particulates and precipitated particles that can be described adequately as filler within the matrix. The reinforcements may be polymers, metals, ceramics, or other materials. Sandwich constructions are covered by this guide via identification of the core material. These guidelines are suitable for the identification of composites in simple shapes of constant thickness; for example, plates or tubes. For complex structures, additional information relevant to a specific application may be required.

4.6 Classification of composite materials is complicated by the fact that composites are formed by combining different materials in varying amounts and configurations; this results in an infinite number of possibilities. An effective identification scheme must be capable of possible combinations without overburdening the system with details relevant only to a limited number of material systems. This guide provides both essential data elements and data elements that are considered desirable but not essential. Data elements are considered essential if they are required to make a meaningful comparison of property data from different sources.

4.7 Identification of constituent materials of the composites is included to the level considered necessary for identification of the composite.

4.8 Comparison of property data from different databases will be most meaningful if all the essential information defined by the guide is present. Comparison may still be possible if essential information is omitted, but the usefulness of the comparison may be greatly reduced.

4.9 For identification of composite materials, Table 1 (Part A) and Tables 2 and 3 shall be used.

1.1 This guide establishes essential and desirable identification elements for fiber-reinforced composite materials and for fibers, fillers, and core materials, matrices, preforms, prepregs, processes, and parts used in these composite materials. This guide is intended for preparing test reports, databases, and material documents.

1.2 These guidelines are specific to fiber-reinforced polymer-matrix composite materials. Composite materials, which also contain particulates or precipitated particles, are also included, provided they can be described adequately as a filler in the matrix.

1.3 The materials covered by this guide include fibers, both continuous and discontinuous, and fillers of various geometries which are used as reinforcements in composite materials, as well as core materials used in sandwich composites, matrices both thermoset and thermoplastic, fiber preforms, prepreg product forms, manufacturing processes, and generic part forms. Cores may be foam, honeycomb, or naturally occurring materials such as balsa wood. These materials are distinguished from bulk materials by the importance of their specialized geometric forms to their properties. This difference is reflected in the use of geometry, along with chemistry, as a primary basis for classification. Additional data elements that are considered desirable, but not essential, are also defined. The purpose is to allow the meaningful comparison of data from different sources.

1.4 Data elements in this guide are relevant to test data, data as obtained in the test laboratory and historically recorded in laboratory notebooks. Property data, data that have been analyzed and reviewed, may only need a subset of these data elements.

1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.