||Determine Filled-Hole Strength of Composites with New ASTM Standard
When stress engineers create design values for lay-ups used in
composite structures, they sometimes require both open-hole and
filled-hole strength data.
Aerospace scientists on ASTM Composites Committee D30 recently developed standard testing for filled-hole tension
Published this year, ASTM D 6742/D 6742M, Standard Practice for Filled-Hole Tension and Compression Testing
of Polymer Matrix Composite Laminates, applies to structures utilizing
bolted joints in aircraft, spacecraft, marine structures, and
Adam Sawicki, an engineer-scientist with The Boeing Company, Philadelphia,
Pa., said, When we generate design data to size an aircraft,
we consider the worst casefilled hole or open holeand we test
both conditions. Sawicki drafted the standard with input from
an ASTM task group of stress analysts from leading aerospace corporations.
The practice supplements open-hole tests in:
ASTM D 5766/D 5766M, Standard Test Method for Open Hole Tensile Strength of Polymer
Matrix Composite Laminates; and
D 6484/D 6484M, Standard Test Method for Open-Hole Compressive Strength of Polymer
Matrix Composite Laminates.
The task group based key sections of the standard on fastener
torque and clearance issues reported in Failure Mechanisms in
Compression-Loaded Composite Laminates Containing Open and Filled
Holes, by Sawicki, and P. Minguet, Journal of Reinforced Plastics
and Composites, Vol. 18, No. 18 (1999). Five studies sponsored
by NASA, the U.S. Air Force, the Federal Aviation Administration,
and others also influenced the standards content.
The standard provides:
Procedures and measurements necessary for filled-hole testing;
Guidance on factors influencing filled-hole tensile and compressive
Historical references on values likely to be filled-hole vs.
A table with examples of common modes in open-hole tension and
compression testing covering a variety of failure locations and
modes; and more.
For further technical information, contact Adam Sawicki, The Boeing Company, Philadelphia, Pa. (phone: 610/591-2807).
Committee D30 meets Oct. 23-25 at Purdue University, West Lafayette,
Ind., in conjunction with the American Society of Composites.
For meeting or membership details, contact Jim Olshefsky, manager, ASTM Technical Committees (phone: 610/832-9714). //
Copyright 2002, ASTM