Grips and Fixtures for Materials testing
TTS can offer new grips and fixtures to suit any test application and are designed to fit most OEM machines. All our grips and fixtures are manufactured here in the UK to the most exacting specifications.
Our grips are supplied and priced as a pair and include a standard set of jaws, exceptions are fixtures such as bending jigs, friction testing etc where the upper part is completely different from the bottom. All grips and fixtures come complete and ready to use and are adapted to suit your particular testing machine. Due to the large quantity of different testing machines in the market we keep our grips as piece parts and assemble to order.
Our grips are significantly more cost effective than OEM grips and but made to equally high standards.
Specially designed for accurate and repeatable testing of composite materials, this range includes compression fixtures, short beam shear test jigs, peel jigs and tensile test jigs.
Precision grips and fixtures enable you to perform mechanical tests to assess the full characterization of the properties of anisotropic and homogeneous composite materials. All our test fixtures can also be changed quickly and easily so you can perform a wide range of tests and reduce productivity time lost through to test delays.
Our compression testing fixtures are compliant with all relevant ASTM, ISO, prEN and DIN test standards.
ASTM D 6641 Compression of Composite Laminates
This is a combined loading fixture to ASTM D 6641 for determining the compressive strength of polymer matrix composite materials.
The load is introduced to the sample through a combination of shear load and end load.
The sample is 5.5” as per the standard and can be tabbed or untabbed.
The gripping surfaces are coated with synthetic diamond particles to give a good transference of the shear portion of the load.
This test requires two compression platens to apply the load to the ASTM fixture.
ASTM D 695 Compression Anti-Buckling Fixture for Composites
This fixture supports a composite compression sample to prevent buckling of the sample before compression failure of the bulk material.
The fixture includes the Boeing/SACMA mounting fixture, which also allows space for attaching strain gauges to one or both faces of the sample.
Please note this fixture is compressed between two compression platens that must be ordered separately; ST6/4 would be suitable.
This fixture could also be used for ASTM D 3849/Boeing BSS 7260 /SACMA SRM 1-88 and EN 2850
ASTM D 5748-95 (2012) Puncture Jig
This fixture is used to measure the energy to rupture of shrink wrap and other films by plunging a probe through a clamped sample of the film.
The sample is clamped between two rubber-coated plates, each with a 4 inch or 102 mm hole in the centre.
A ¾ inch or 19mm diameter Teflon hemispherical probe is used to penetrate the sample and the energy to break, etc, is calculated according to the standard.
ASTM D 3410
This fixture complies with the requirements of ASTM D 3410 for testing composite materials in compression. The top and bottom halves of the fixture are guided on precision linear bearings to ensure accurate alignment. Samples are first loaded into an alignment jig with the jaws to ensure the sample is square to the axis of the jaw faces. The sample/jaw face assembly is then loaded in to the fixture and the two halves brought together to perform the test.
Separate jaw faces are included with the jig to allow testing within 3 ranges of thickness, 3-9 mm, 7-12 mm and 10-15 mm. Jaw faces are hardened to approximately 60HRC and have a fine tooth pattern on the gripping surface. Alternative hard particle faces can be supplied if required.
ASTM D 3410
Designed to take a restricted sample size, both in width and thickness compared to the full range fixture ST55, this fixture is both lighter and cheaper. It complies with the requirements of ASTM D 3410 for testing composite materials in compression. The top and bottom halves of the fixture are guided on precision linear bearings to ensure accurate alignment. Samples are first loaded in to an alignment jig with the jaws to ensure the sample is square to the axis of the jaw faces. The sample/jaw face assembly is then loaded in to the fixture and the two halves brought together to perform the test.
Jaw faces are hardened to approximately 60HRC and have a fine tooth pattern on the gripping surface. Alternative hard particle faces can be supplied if required.
ASTM D 3410 Celanese test
The German DIN standard test is a modification of the American ASTM D 3410 Celanese test. The Celanese test jig has conical tapered wedges which only contact correctly at one position in the body, thus sample thickness is critical to get full wedge contact with the body. The DIN fixture has straight tapered wedges allowing full contact with the body of the fixture.
The fixture will accommodate both Celanese and DIN samples. Jaw faces to accommodate other sample sizes can be considered within the overall restraints of the fixture. Standard faces are cut with fine serration’s and hardened to approximately 60HRC. Alternative faces such as hard particles can be supplied.
An alternative guidance system using linear bearings and guide rods can be supplied with this fixture, this is designated ST57/2.
100mm diameter Steel compression platen. Price per pair
ST57/1 DIN 65 380 Celanese Compression Fixture
ST57/1 DIN 65 380 Celanese Compression Fixture
As per ST57/1 but with the addition of guide bearings.
Short Beam Shear Test
A guided three point bend jig in accordance with ASTM D 2344 designed to test the interlaminar shear properties of composite materials. The lower span is adjustable to allow the span/sample thickness ratio to be set in accordance with the standard. Precision guide shafts and linear bearings ensure the alignment remains correct throughout the test. Side guidance for centralising the sample is provided.
Anvils are hardened steel. The lower support anvils are 3.2mm ( 1/8" ) diameter and the upper loading anvil is 6.35mm ( 1/4" ) diameter. All anvils can rotate about their axes during the test. Load can be applied to the fixture either through a pair of compression plattens, or via the loose fitting connection shown. This connection allows for angular misalignment of the loading rod.
Climbing Drum Peel Jig
Typically this jig is used to test aluminium faced honeycomb cored structural panels used in the aerospace and similar industries. The test measures the force required to peel the facing sheet from the core, thus testing the effectiveness of the adhesive joint. An alternative use is for testing the adhesive strength of bonded assemblies. A flat steel plate is supplied with the fixture to support this type of sample in accordance with the ASTM standard.
To perform the test, one end of one of the facing panels is attached to an eccentric roller grip attached to the loadcell of the machine. The opposite end of the opposing facing panel is attached to the eccentric roller on the drum. The drum has two steel bands wrapped around it’s circumference, these are attached to the lower crosshead of the machine. As the upper crosshead is moved away the bands rotate the drum which climbs up the panel, peeling off the facing sheet.
Floating Roller Peel Test DIN 53 289/ASTM D 3167
This jig is used to test the peel strength of laminated samples where the backing sheet is rigid and the facing sheet is flexible. It complies with both the DIN and ASTM standards. It is an alternative to the climbing drum jig ST59 for testing laminates. The peel angle is greater than 90 degrees.
Samples as defined by the DIN and ASTM standards are near enough identical. The ASTM sample is 10" long with a 2" extension of the flexible layer, sample width is 0.5" cut from a prepared sample of 3" width.
The jig mounts on the upper crosshead of the machine with the sample laying on top of the rollers. The flexible sheet is facing downwards and the extended end is peeled back and bent down between the two rollers to be gripped by a suitable vice attached to the lower crosshead of the machine. As the test proceeds the flexible layer peels off the backing sheet which moves across the rollers to the right.
Split Disc Tensile Test Jig ASTM D 2290
A split ring, is fitted to the inside of the annular shaped sample. The two halves of the split ring are separated by the action of the testing machine, applying a tensile load to two sections of the sample. 4 specimen types are defined, the fixture varies according to the sample type under test. Universal joints are recommended to be used.
Type A specimens are defined in width, thickness and diameter.
Type B specimens have the same width and internal diameter as Type A but the thickness is left as wound and cured.
The reduced section samples can be any diameter or thickness, according to the product they are taken from. Overall width and reduced width are defined by the standard as 0.5" and 0.25" respectively.