More D The standard configuration for each procedure is very specific and is intended primarily for development of quantitative double- and single-shear bearing response data for material comparison and structural design. Procedures A and D, the double-shear configurations, with a single fastener loaded in shear and reacted by laminate tension or compression, are particularly recommended for basic material evaluation and comparison. Procedures B and C, the single-shear, single- or double-fastener configurations are more useful in evaluation of specific joint configurations, including fastener failure modes. The Procedure B specimen may be tested in either an unstabilized no support fixture or stabilized configuration. The unstabilized configuration is intended for tensile loading and the stabilized configuration is intended for compressive loading although tensile loading is permitted.
|Country:||Trinidad & Tobago|
|Published (Last):||13 September 2017|
|PDF File Size:||5.83 Mb|
|ePub File Size:||15.69 Mb|
|Price:||Free* [*Free Regsitration Required]|
Procedure B is actually a specimen support fixture and is described on its own page of this website. The other three procedures are pin bearing fixtures, as will be described here.
That is, the pin in the fixture attempts to shear out a segment of the composite laminate test specimen by creating two shear planes in the pin. The standard test specimen is 5. This simple test fixture is shown in Fig. The two halves of the fixture are separated by a spacer not provided of the same thickness as the specimen being tested.
Obviously, a piece of the same test material can be used as a spacer, if desired. Since a raised boss is present at the pin hole, the opposite end of the fixture is thicker by an equal amount so that the specimen is uniformly supported when gripped. The end of the fixture with the spacer in place is gripped in a standard tensile wedge grip. Each half of the fixture is 0. The free end of the specimen is held in a second tensile wedge grip.
A tensile load is applied until a maximum loading has been reached, monitoring both applied force and hole deformation, as described in the ASTM standard. Sometimes the customer has a requirement to test non-standard specimen sizes, requiring Wyoming Test Fixtures, Inc. An example is shown in Fig. An alternate version of the test fixture shown in Figs. As described in Section H-2, the SACMA fixture is much easier to use since the specimen holder is one piece, with adjustable bushings to accommodate variations in specimen thickness.
That is, a single shear plane is developed in the loading pin as the tensile load is applied. The test fixture is shown in Fig. Or a pin can be used. The flat tang at the top of the test fixture is gripped in a wedge grip and a tensile force is applied to the lower end of the specimen. The maximum force attained and the deformation of the hole in the specimen are recorded. The fixture is shown in Fig. The two lower components of the fixture are spread apart to permit inserting the 1.
A pin or fastener is inserted in the hole, the fastener being torqued as desired. The upper end of the fixture is held in a grip, as is the lower end of the test specimen. The specimen is kept short enough to avoid buckling. The applied compressive loading induces a double shear in both the specimen and the loading fastener or pin. Load at failure and hole deformation are measured.
ASTM D5961 Composite Bearing Response Testing
The bearing force is created by tension or compression loading. It can be applied through a lightly torqued fastener or pin that is reacted in single shear or double shear depending on the test procedure. Results from each procedure should not generally be expected to yield comparable results due to difference in the loading direction, localized damage modes, support fixture friction and specimen dimension differences. The specimen should have a centerline hole, 18mm 0. It is important to maintain the specimen width to hole diameter at 6, even if the specimen dimensions change.
ASTM D5961 PDF
More D Scope 1. Standard specimen configurations using fixed values of test parameters are described for each procedure. However, when fully documented in the test report, a number of test parameters may be optionally varied. The composite material forms are limited to continuous-fiber or discontinuous-fiber tape or fabric, or both reinforced composites for which the laminate is balanced and symmetric with respect to the test direction. The range of acceptable test laminates and thicknesses are described in 8. Note that the scope of this test method is limited to bearing and fastener failure modes.