Alignment Fixtures

Exact axial alignment of the test axis of the materials testing system is a basic requirement for determining accurate characteristic values.

Alignment must be performed very carefully, particularly when testing brittle materials such as fiber composites or certain metals.

Alignment fixture for alignment measurement

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Advantages and features
Exact alignment measurement
Mounting the alignment fixture
Verifying the test axis alignment
Technical overview
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Key Advantages and Features

Reliable test results through precise alignment of the test axes
Accurate positioning, reproducible and play-free adaption in each axis guarantees reliable test results
Angle and offset errors can be set independently from each other easily and quickly
Secure gripping of the alignment fixture for long-term retention of any adjustments
Adapting to top crossheads, moving crossheads, and base crossheads enables a flexible range of application
At a force level of 250 kN, there is an option that includes a flange interface, which allows for shorter test arrangements and a higher degree of stiffness

Exact Alignment Measurement

Function description

The alignment fixture is used to accurately compensate for angular and offset errors in the test arrangement.

The alignment fixture is an alignment element and is mounted directly on the testing system’s base crosshead. The adjustment screws are used first to adjust the angular error and then the axial offset. The screw configuration for making adjustments in the X and Y direction makes it possible to correct errors in their respective working direction. The alignment can take place in the loading state.

Alignment measurement

Precise guidelines regarding maximum permissible transverse loads are established in the respective application standards.

To verify machine accuracy, adjustment must take place in a loaded state using optionally available strain-gauged alignment specimens, measurement amplifiers, and ZwickRoell testXpert III testing software. The calculation routines comply with ASTM E1012.

Purely mechanical adjustment in an unloaded state can be performed via the mounting studs or via a divided specimen clamped in the specimen grips.

Mounting the Alignment Fixture

Alignment fixture in flange connection mounted between the load cell and the specimen grip (image on left)
Alignment fixture with bolt connection mounted directly on the crosshead (image on right)

Learn more about our alignment measurement services

Alignment Measurement—Verifying Test Axis Alignment

Technical Overview