ASTM C297/C297M-16 (2024) PDF

Full title and description

St ASTM C297/C297M-16 (2024) — Standard Test Method for Flatwise Tensile Strength of Sandwich Constructions. This document describes a laboratory test procedure to determine the flatwise tensile strength of sandwich panels, including the strength of the core material, the core‑to‑facing bond, or the facing when subjected to a uniaxial tensile load normal to the panel plane.

Abstract

This standard specifies specimen preparation, loading-fixture requirements, loading procedure, rate of loading, calculation of flatwise tensile strength, and required reporting information for sandwich constructions with continuous or discontinuous core bonding surfaces (e.g., balsa, foam, honeycomb). The values are provided in both SI and inch‑pound units which are to be treated independently.

General information

• Status: Active (2016 edition reapproved/issued in 2024 as C297/C297M-16 (R2024)).
• Publication date: 2024 (reapproved/issued in 2024 — listed by publishers with effective dates in August 2024).
• Publisher: ASTM International (American Society for Testing and Materials).
• ICS / categories: 83.120 (Reinforced plastics / composite sandwich constructions).
• Edition / version: C297/C297M-16 (2016 edition) — reapproved/issued with R2024 activity (commonly shown as C297/C297M-16(2024) or C297/C297M: 2016: R2024).
• Number of pages: 8 pages.

Scope

Defines a laboratory test to measure flatwise tensile strength of sandwich construction specimens. The method covers continuous-core (foams, balsa) and discontinuous-core (honeycomb) forms, bonding of loading blocks to specimen faces, test-fixture alignment, loading rate, and calculation/reporting of tensile strength for core, core‑to‑facing bond, or facing failure modes. SI and inch‑pound unit systems are provided and treated independently.

Key topics and requirements

• Specimen preparation and dimensions — trimming, faceplate attachment (loading blocks) and adhesive bonding practices.
• Fixture and alignment — dual‑yoke or equivalent flatwise tensile fixtures to transmit load normal to the sandwich plane.
• Loading rate and control — specified constant rate of crosshead movement or stress/strain rate to failure.
• Calculation of flatwise tensile strength — peak load divided by specified area, reported in MPa or psi (unit systems treated separately).
• Failure mode classification and reporting — core failure, core‑to‑facing bond failure, or facing failure.
• Permitted core types and applicability — continuous bonding surfaces (balsa, foam) and discontinuous bonding surfaces (honeycomb) explicitly covered.
• Data reporting requirements — specimen identification, dimensions, adhesive and facing descriptions, test conditions, and units used.
• Safety and handling notes — user responsibility to observe appropriate lab safety and environmental practices when performing the test.

(Summary based on the standard test method and common laboratory practice.)

Typical use and users

Used by materials testing laboratories, composite and sandwich‑panel manufacturers, aerospace and marine industries, quality control/assurance teams, and research organizations to assess bond integrity and core/facing tensile properties of sandwich constructions. Equipment vendors and test‑fixture suppliers commonly reference this method when offering fixtures and test services.

Related standards

Standards commonly referenced with C297 include test methods and specifications for sandwich/core materials and related mechanical tests, for example: ASTM C272/C272M (water absorption of core materials for sandwich constructions), ASTM C363/C363M (node tensile strength of honeycomb core materials), ASTM D2734 (void content/ignition-weight tests for composite cores), and other composite mechanical property methods such as D3410/D3410M. These related documents help characterize core material properties and complementary mechanical behaviors.

Keywords

sandwich construction, flatwise tensile, core-to-facing bond, core tensile strength, honeycomb, foam core, balsa core, loading blocks, tensile adhesion, dual‑yoke fixture, ASTM C297.

FAQ

Q: What is this standard?

A: ASTM C297/C297M-16 (reapproved 2024) is the Standard Test Method for Flatwise Tensile Strength of Sandwich Constructions used to measure the tensile strength normal to the plane of sandwich panels and to evaluate core, facing, or core‑to‑facing bond strength.

Q: What does it cover?

A: It covers specimen preparation, loading‑block attachment, test fixtures and alignment, loading rate, calculation of tensile strength, failure‑mode classification, and reporting requirements for sandwich panels with continuous or discontinuous core bonding surfaces. Both SI and inch‑pound units are provided and treated independently.

Q: Who typically uses it?

A: Test laboratories, composite and sandwich panel manufacturers, aerospace, marine, automotive and research organizations, and suppliers of testing fixtures and services. Results are used for quality control, design verification, supplier qualification, and R&D.

Q: Is it current or superseded?

A: The technical content originates from the 2016 edition (C297/C297M-16) and was subject to reapproval/reissue activity in 2024 (commonly referenced as C297/C297M-16 (2024) or C297/C297M: 2016: R2024). The document is listed as active/current following the 2024 reapproval. Always confirm the latest status with ASTM or an official standards provider before relying on a specific edition.

Q: Is it part of a series?

A: It is part of ASTM’s body of test methods for sandwich and composite materials and is frequently used alongside other ASTM tests for core characterization and composite mechanical properties (examples include C272/C272M, C363/C363M, D2734, D3410).

Q: What are the key keywords?

A: flatwise tensile, sandwich construction, core, facing, core‑to‑facing bond, honeycomb, foam, balsa, tensile strength.