Bone Cement Fatigue Test Fixture – 30 kN

Fatigue grips for acrylic bone cement and rigid specimens

The UGC-VG-160 is a compact, lightweight pair of fatigue grips built for constant-amplitude, force-controlled tests on acrylic bone cement to ASTM F2118. Bone cement specimens are small and brittle, and a fatigue test can run for a very large number of cycles in tension and compression. Any looseness in the grips shows up as a dead band each time the load crosses zero, and any excess mass on the actuator limits the frequency you can run. This fixture addresses both: it clamps without backlash and weighs about 1.5 kg (3.3 lb) per grip. Orthopedic device makers, cement suppliers and biomechanics labs are the core users.

How it works

The grips are adjusted with a backlash-free mechanism, so once the specimen is clamped there is no free play to take up when the load reverses from tension to compression. High clamping force holds the specimen without relying on the test load to tighten the jaws. Grips and jaws are made of steel hardened to 58 HRC and nickel-coated, rated from -40 to +280 °C, and each grip mounts on an M12 x 1.75 threaded stud for a stiff, aligned load train.

Flat or round specimens

• Flat-specimen version: serrated 30 x 30 mm jaws (1.2 x 45° serration), opening 0–12 mm, set up for ASTM F2118 specimens

• Round-specimen version: V-jaws for Ø 4–12 mm with a 1 mm tooth pitch

• Diamond-coated jaws: 30 x 30 mm, opening 0–10 mm, for hard or polished surfaces

Beyond bone cement

The same grips suit fatigue work on medical implant materials, steel and aluminum, and CFRP and fiberglass composites, including in temperature chambers within the -40 to +280 °C range. Special builds extend the concept: high-capacity fatigue grips at 50, 100 or 200 kN, and a 30 kN high-temperature version for up to +600 °C with a TiN coating, both on request.

Machine fit

Fatigue tests to ASTM F2118 need a dynamic test system, so these grips are usually fitted to the customer's servo-hydraulic or electrodynamic frame. If its load cell or actuator uses a thread other than M12 x 1.75, we supply adapters. For chamber work see our environmental chambers, and for heavier composite fatigue loads compare the UGC-VG-060 dynamic vise grip rated 100 kN. Other cyclic-loading fixtures are grouped under fatigue grips.

Tell us whether your specimens are flat or round, their size, the capacity and test temperature, and your coupling thread, and we will configure the pair: request a quote.