TEST FIXTUREA clamping fixture is used to secure one half of the tibial tray, simulating a fully supported condyle. The other unsupported condyle is then subjected to physiologically representative loading. By using our patented Dynacell™ load cell, dynamic inertial errors (such as those caused by the fixturing and from hydro-dynamics that result when testing in an environmental bath) can be removed, allowing for a more accurate measurement of load being applied to the specimen.
TEST FIXTURETibial tray tests are carried out in force control with the peak force set to 10% of the maximum force the tray can withstand. 900N is a typical value, but depending on the material, the force used is often in excess of 2000N. The number of cycles is determined by the user, but a typical value is 10 million. 10 Hz is the prescribed frequency for this test (although higher frequencies can be used if evidence that test results match those obtained at 10Hz is provided). Tests are run until either the spacer thickness is reduced to 3 mm or fragments, the tibial tray fails, cracks are detected in the specimen following visual inspection or non-destructive inspection or finally, if the maximum number of cycles is reached.
TEST FIXTURETibial tray tests are carried out in force control with the peak force set to 10% of the maximum force the tray can withstand. 900N is a typical value, but depending on the material, the force used is often in excess of 2000N. The number of cycles is determined by the user, but a typical value is 10 million. 10 Hz is the prescribed frequency for this test (although higher frequencies can be used if evidence that test results match those obtained at 10Hz is provided). Tests are run until either the spacer thickness is reduced to 3 mm or fragments, the tibial tray fails, cracks are detected in the specimen following visual inspection or non-destructive inspection or finally, if the maximum number of cycles is reached.