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- Standard / ASTM-D5766-D5766-M
ASTM D5766 / D5766 M
ASTM D5766 / D5766 M
Structural applications with polymer matrix composites always include holes, cutouts, or fastener penetrations with these high-stress concentration areas. ASTM D5766/D5766M is the standard test method to obtain the damage sensitivity and notch-effect data needed by structural engineers and material qualifiers through measurements of tensile strength of composite laminates at these open hole locations. Presto Stantest tensile testing machines deliver the precision load application and measurement capability that ASTM D5766/D5766M-compliant composite testing demands.
Significance
Open holes represent the most mechanically critical regions in composite structural assemblies — stress concentrations at hole boundaries can reduce effective tensile strength significantly below the unnotched laminate value. ASTM D5766/D5766M quantifies this reduction, enabling aerospace, automotive, and defence manufacturers to establish design allowables, validate material selections, compare composite systems, and verify manufacturing quality at fastener and joining locations.
Scope
ASTM D5766/D5766M covers tensile strength testing of multidirectional polymer matrix composite laminates containing a centrally located open hole of defined diameter-to-width ratio. Specimens are loaded uniaxially to failure under controlled crosshead displacement, with failure load, failure mode, and hole-bearing area all recorded and reported.