	US 7,574,922 B2
	Test apparatus to determine the shear strength of a composite sandwich beam under a high hydrostatic load
Robert F. Doleski, Middletown, R.I. (US); Stanley J. Olson, Newport, R.I. (US); and Stephen F. Oliver, Portsmouth, R.I. (US)
Assigned to The United States of America as represented by the Secretary of the Navy, Washington, D.C. (US)
Filed on Jul. 12, 2007, as Appl. No. 11/776,776.
Prior Publication US 2009/0013796 A1, Jan. 15, 2009
Int. Cl. G01N 3/24 (2006.01)

U.S. Cl. 73—841

20 Claims

1. A test apparatus for determining shear strength of an insertable and removable composite sandwich beam as a test piece, said apparatus comprising:

an enclosure with a first aperture at a first end and a second aperture at a second end with a cutout along at least one side of said enclosure with the cutout extending from the second end partially to the first end wherein the cutout allows removable and insertion of the composite sandwich in said enclosure;

a bladder sized to be insertable through the first aperture and expandable to create a volume within said enclosure with said bladder including a bladder flange integral to and extending outward from a first end of said bladder and to said at least one side of said enclosure;

a blind flange mechanically attachable to the first end of said enclosure and said bladder flange such that said blind flange is capable of securing said bladder flange to said enclosure;

at least one support platform for the insertable and removable composite sandwich beam, said support platform sized to be positioned at an open end of a perimeter of the cutout;

at least one pressure fitting fluidly connected to said bladder through said blind flange, said pressure fitting capable of fluidly attaching to a pressure source to pressurize said bladder; and

at least one drain fitting fluidly connected to said bladder for draining said bladder;

wherein said bladder once filled to a predetermined pressure by way of said pressure fitting imparts a measurable hydrostatic load to the insertable and removable composite sandwich beam as a result of a constraining action by said enclosure and said blind flange during the filling action of said bladder.