Sandwich Flexural Stiffness by ASTM D7249

Facing properties of sandwich constructions by long beam flexure, so called four point flexure.

Four point flexure of flat sandwich constructions to produce curvature of the sandwich facing plane. The test provides information on sandwich flexural stiffness, core shear strength, shear modulus, facing compressive strength and facing tensile strength. Core materials applicable include continuous (foams) and discontinuous bonding surfaces (honeycomb).

Test procedure: Bonded strain gages are applied to the specimens (if applicable). Specimens are conditioned (if required). The specimens are installed into the 4-point test fixture of the Universal Test Machine. The fixture and specimen are aligned – specimen perpendicular to the loading bars with the bars perpendicular to the plane of the specimen facing. Initiate a compressive force until failure. The four-point loading configuration is standard.

Specimen size: Five specimens tested at thickness. Standard specimens are rectangular 75 mm [3.0 inch] width x 600 mm [24.0 inch] long.

Data: From 4-point flexure results the following calculations can be made:

  1. Force-Displacement Behavior
  2. Facing Ultimate Stress
  3. Ultimate Facing Stress
  4. Effective Compressive and Tensile Chord Modulus
  5. Effective Sandwich Flexural Stiffness
  6. Failure type/mode

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Standards may be obtained from appropriate standard authorities.

 
Need help or have a question? +1 413 499 0983
 

Need help or have a question?

+1 413 499 0983
Wilton UK:
+44 1642 435 788
Benelux:
+31 88 126 8888
France:
+33 (0) 385 99 12 80
APAC:
+65 6805 4800
Germany:
0800 5855888
+49 711 27311 152
Switzerland:
+41 61 686 4800
Mexico:
01 800 5468 3783
+52 55 5091 2150
Brazil:
+55 11 2322 8033
Australia:
+61 1300 046 837
India:
+91 (22) 4245 0204