Standard Test Method for Local Buckling and Crippling under Axial Compressive Loading

Importancia y uso:

5.1 This test method is designed to produce composite stiffener cross-section local buckling and crippling data for research and development, and for structural design and analysis. The standard generic configurations for this procedure provide data for two types of cross-section segments: one-edge-free and no-edge-free. This type of data is used in classical stiffener analysis methods. Compressive loading of composite column type specimens may exhibit one of four modes: (1) a compression material strength failure, (2) an overall column flexural, torsional, and or flexural-torsional instability, (3) a local instability followed by a continued post-buckled force carrying capability which eventually results in a material strength failure, or (4) a combination of local and overall instability followed by post-buckling failure. The first two modes are outside the scope of this test method. The latter two modes are categorized as crippling failure and is the purpose of this test method.

5.1.1 The desired failure mode is characterized by an initial linear elastic structural deformation. Continued loading eventually renders one of the cross-sectional segments unstable. Additional loading beyond this point of initial buckling exhibits a pattern of local lateral deflections or buckles. These deflections will grow, and possibly change modes, until catastrophic column failure occurs. This failure is considered the ultimate crippling stress for the buckled segments.

5.2 General factors that influence the mechanical response of composite laminates and should therefore be reported include the following: material, methods of material preparation and lay-up, specimen stacking sequence, specimen preparation, specimen conditioning, environment of testing, specimen alignment and gripping, speed of testing, time held at test temperature, void content, and volume percent reinforcement.

Subcomité:

D30.05

Referida por:

D8511_D8511M-23, D4762-23

Volúmen:

15.03

Número ICS:

59.100.01 (Materials for the reinforcement of composites in general)

Palabras clave:

composite materials; compression test; crippling; local buckling;