ASTM C393/C393M-16
Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure

Standard No.

ASTM C393/C393M-16

Release Date

2016

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM C393/C393M-20

Latest

ASTM C393/C393M-20

Scope

5.1 Flexure tests on flat sandwich construction may be conducted to determine the sandwich flexural stiffness, the core shear strength and shear modulus, or the facings compressive and tensile strengths. Tests to evaluate core shear strength may also be used to evaluate core-to-facing bonds.

5.2 This test method is limited to obtaining the core shear strength or core-to-facing shear strength and the stiffness of the sandwich beam, and to obtaining load-deflection data for use in calculating sandwich beam flexural and shear stiffness using Practice D7250/D7250M.

Note 1: Core shear strength and shear modulus are best determined in accordance with Test Method C273 provided bare core material is available.

5.3 Facing strength is best determined in accordance with Test Method D7249/D7249M.

5.4 Practice D7250/D7250M covers the determination of sandwich flexural and shear stiffness and core shear modulus using calculations involving measured deflections of sandwich flexure specimens.

5.5 This test method can be used to produce core shear strength and core-to-facing shear strength data for structural design allowables, material specifications, and research and development applications; it may also be used as a quality control test for bonded sandwich panels.

5.6 Factors that influence the shear strength and shall therefore be reported include the following: facing material, core material, adhesive material, methods of material fabrication, core geometry (cell size), core density, adhesive thickness, specimen geometry, specimen preparation, specimen conditioning, environment of testing, specimen alignment, loading procedure, speed of testing, and adhesive void content. Further, core-to-facing strength may be different between precured/bonded and co-cured facings in sandwich panels with the same core and facing material.

Note 2: Concentrated loads on beams with thin facings and low density cores can produce results that are difficult to interpret, especially close to the failure point. Wider load pads with rubber pads may assist in distributing the loads.

1.1 This test method covers determination of the core shear properties of flat sandwich constructions subjected to flexure in such a manner that the applied moments produce curvature of the sandwich facing planes. Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as honeycomb).

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of ......

ASTM C393/C393M-16 Referenced Document

• ASTM C273 Standard Test Method for Shear Properties of Sandwich Core Materials
• ASTM D3878 Standard Terminology Composite Materials
• ASTM D5229/D5229M Standard Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite Materials
• ASTM D7249/D7249M Standard Test Method for Facesheet Properties of Sandwich Constructions by Long Beam Flexure
• ASTM D7250/D7250M Standard Practice for Determining Sandwich Beam Flexural and Shear Stiffness
• ASTM D883 Standard Terminology Relating to Plastics
• ASTM E122 Standard Practice for Calculating Sample Size to Estimate, With a Specified Tolerable Error, the Average for Characteristic of a Lot or Process
• ASTM E177 Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• ASTM E4 Standard Practices for Force Verification of Testing Machines
• ASTM E456 Standard Terminology for Relating to Quality and Statistics
• ASTM E6 Standard Terminology Relating to Methods of Mechanical Testing

ASTM C393/C393M-16 history

• 2020 ASTM C393/C393M-20 Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure
• 2016 ASTM C393/C393M-16 Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure
• 2011 ASTM C393/C393M-11e1 Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure
• 2011 ASTM C393/C393M-11 Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure
• 2006 ASTM C393/C393M-06 Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure
• 2000 ASTM C393-00 Standard Test Method for Flexural Properties of Sandwich Constructions