Standard Test Methods for Bend Testing of Metallic Flat Materials for Spring Applications Involving Static Loading

Importancia y uso:

4.1 Measurements of bending proof strength, offset yield strength in bending, and modulus of elasticity in bending should be made for materials whose principal stressing mode is bending. For many materials, the tensile and compressive moduli are somewhat different. Since the modulus of elasticity in bending is a combination of the tensile and compressive moduli, it is often different from each of them.

4.2 Precise measurements of the modulus of elasticity in bending offset yield strength in bending, and bending proof strength require due regard for numerous variables that can affect their determination. These include (1) material characteristics such as specimen orientation with respect to the rolling direction, grain size, residual stresses, previous strain history, dimensions and specimen preparation, orientation of deformed grains relative to the direction of the normal stress; and (2) test conditions, such as temperature, temperature variations, condition of the test equipment, and adherence to the test procedure.

4.3 Fundamental Assumptions: 

4.3.1 The test section of the specimen is subjected to uniform bending moment, which produces a uniform strain at the outer fiber throughout the gauge length of the specimen (applies to Test Method C only).

4.3.2 The neutral axis is located at the centerline of the thickness of the test specimen.

4.3.3 Transverse cross sections of the beam remain plane and normal to the longitudinal fiber of the beam during bending.

4.3.4 The effect of shear stresses is negligible.

Subcomité:

E28.02

Volúmen:

03.01

Número ICS:

21.160 (Springs)

Palabras clave:

bending; bending proof strength; modulus of elasticity in bending; offset yield strength in bending; spring;