Standard Test Method for Measuring the Curved Beam Strength of a Fiber-Reinforced Polymer-Matrix Composite

Importancia y uso:

5.1 Susceptibility to delamination is one of the major design concerns for many advanced laminated composite structures. Complex structural geometries can result in out-of-plane stresses, which may be difficult to analyze. When curved structural details are loaded such that the deformation results in an increase in the radius of curvature, interlaminar tensile stress and delaminations can result. Knowledge of a laminated composite material’s resistance to interlaminar fracture is useful for product development and material selection. Failure criteria and design allowables involving out-of-plane stresses may not be readily available or may be poorly validated, requiring additional experimental data.

5.2 This test method can serve the following purposes:

5.2.1 To measure a curved-beam strength;

5.2.2 To measure an interlaminar strength when using a unidirectional specimen where all fibers are oriented 0° relative to the long straight edges of the specimen;

5.2.3 To establish quantitatively the effect of fiber surface treatment, local variations in fiber volume fraction, and processing and environmental variables on the curved beam strength or the interlaminar (through-the-thickness) tensile strength of a particular composite material;

5.2.4 To compare quantitatively the relative curved-beam strength or interlaminar tensile strengths of composite materials with different constituents;

5.2.5 To compare quantitatively the values of the curved-beam strength or interlaminar tensile strengths obtained from different batches of a specific composite material, for example, to use as a material screening criterion, to use for quality assurance, or to develop a design allowable;

5.2.6 To produce out-of-plane structural failure data for structural design and analysis; and

5.2.7 To develop failure criteria for predicting failures caused by out-of-plane stresses.

Subcomité:

D30.06

Referida por:

D6856_D6856M-23, D4762-23

Volúmen:

15.03

Número ICS:

83.120 (Reinforced plastics)

Palabras clave:

composite materials; curved beam; curved beam strength; interlaminar tensile strength; out-of-plane tension; through-the-thickness strength;