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.

Key Advantages and Features

  • Significant reduction in time and effort required for adjustment
  • Convenient adjustment, even under tensile or compression load
  • Ample adjustment range
  • Angular and axial errors can be corrected independently of each other
  • Secure gripping of the alignment fixture for long-term retention of any adjustments
  • Can be attached to top, moving or base crossheads.
  • A version with flanged interface is available for force level 250kN, enabling a shorter test arrangement and even greater stiffness.

Exact Alignment Measurement

Function description

The alignment fixture is used to accurately compensate for angular and offset errors in the test arrangement. It is an alignment element that is mounted between the testing system's crosshead and the specimen grip or test tool. The adjustment screws are used first to adjust the angular error and then the axis offset. In this way it is possible to adjust each error individually and by means of the configuration. The screw configuration for making adjustments in the X and Y direction makes it possible to correct errors in their respective working direction.

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-gaged alignment specimens, measurement amplifiers, and testXpert® II software application. 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)

Technical Overview

Item no.

058005

058006

068902

Version

50 kN bolts

250 kN bolts

250 kN flange

In conjunction with

AllroundLine and symmetrical specimen grips

AllroundLine and symmetrical specimen grips

AllroundLine and symmetrical specimen grips

Test load, max. (Fmax)

50

250

250

kN

Connection

Bolts Ø36

Bolt Ø60

Flange connection

mm

Load types (symmetric force application)

Tensile/compression/alternating load (static)

Tensile/compression/alternating load (static)

Tensile/compression/alternating load (static)

Permissible bending moment on the mounting stud/flange, max.

1

7.5

30

kNm

Crosshead interface

Centering D70, 8 x M8 on a pitch circle of 115

Centering D70, 8 x M16 on a pitch circle 220

Centering D70, 8 x M16 on a pitch circle 220[1], 8 x M16 on a pitch circle of 264

Specimen grip interface

Bolt D 36g6

Bolt D 60g6

Centering D70, 8 x M16 on a pitch circle 220

Offset adjustment

± 3

±3

±3

mm

Attainable accuracy with offset adjustment

± 0.01

±0.01

±0.01

angular correction

± 1

±0.7

±0.35

°

Attainable accuracy with angle correction

± 0.006

±0.004

±0.002

°

Dimensions:

Overall height

152

211

145

mm

Installation space height

111

138

142

mm

Diameter

180

250

290

mm

Weight, approx.

14

34

49

kg

Ambient temperature

+10 to +35

+10 to +35

+10 to +35

°C

  1. with intermediate flange (optional unit in BPos)
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