The gripping force applied to a test specimen by a grip is determined by hydraulic pressure supplied to the grip. The ideal gripping force is large enough to securely grip the specimen but low enough to minimize damage or deformation of the specimen and to prevent specimen slippage during the test.

In the formulas below
A = Area of the grip piston (cm2 or in2)
L = Maximum axial load applied to the specimen (kN or lbf)
P = Grip supply pressure (MPa or psi)
T = Torque (N-m or lb-in)
D = Diameter of test specimen (mm or in)

Fatigue and monotonic testing
To determine the hydraulic pressure required you need to know the maximum axial load to be applied to the specimen for the test. Calculate the minimum hydraulic pressure required:

For monotonic testing
P = 1.04 x L / A

For fatigue testing
P = 12 x L / A

Axial-Torsional testing
To determine the minimum hydraulic pressure required to grip round specimens for axial/torsional testing you need to know the maximum torque to be applied to the specimen for the test. Calculate the minimum hydraulic pressure required:
P = 7.7 x T / A x D

301 Series Load Frame

Designed specifically to provide fatigue or compression/ tension test capability in only 1.7 sq. ft. (.158 sq. m) of bench space. Typical applications include

  • Cyclic material testing
  • Application of precision force
  • Fatigue testing

These fatigue rated load frames come standard with 6 inch (150 mm) stroke lengths and force ratings from 1.1 KIP (5 kN) to 10 KIP (45 kN). Advanced design, quality components, and variety of options makes the 301 Series Load Frame your best choice for tabletop testing applications

   301 Load Frame

Features

  • Smooth, chrome plated columns – 301 utilizes smooth, chrome plated columns to provide long life and easy crosshead position changes.

  • Infinitely adjustable crosshead – The crosshead is vertically adjustable with infinite resolution. Position of the crosshead is maintained free of backlash by friction clamp locks.

  • Internal Displacement transducer – The actuator has a co-axially mounted LVDT in the piston rod.  The design protects the LVDT and insures accurate displacement signals for the control system.

  • Extremely rigid construction – No intermediate threaded joints or compression joints are utilized and the load is transmitted directly into the crosshead during testing.

  • Ease of mounting – The 301 Series Load Frame requires no tie downs but can be mounted directly to a work surface or on isolation pads. Convenient Size: 20.5"  Wide x 12.0" Deep  x 48" Height

  • Ease of use – The actuator is mounted to the moveable crosshead and the system supplied load cell is mounted directly to fixed position metal base platen, simplifying and accelerating up test setups.

Options

  • Hydraulic crosshead controls – The standard 301 configuration uses a manual crosshead positioning system. Hydraulic lift and lock controls  are also available. Located on the front of the load frame a panel controls crosshead movement. With simple controls you unlock, raise or lower and lock the crosshead. The design ensures a sudden loss of hydraulic power will not result in any unwanted crosshead motion.

  • Vibration isolation mounts – Vibration or dynamic testing can produce unwanted noise and vibration which can be transmitted to the laboratory environment. Isolation pads under the load unit help reduce noise and dampen vibrations transmitted to the laboratory environment.

  • Safety enclosure – A safety enclosure can be fitted around the test area to protect the operator during destruction testing.

  • Accessories – Choose from a wide variety of grips, fixtures, extensometers, larger power supplies and various load cell force ratings.