MTS Series 311 Load Frame - Manual (Page 16)

Series 311 Load Frame 16
Component Identification
Introduction
Component Descriptions
Item Description
Lifting rings Allows the load frame to be moved by lifting the entire load frame.
Crosshead Moves up and down the columns to accommodate different sized specimens
and fixtures. The crosshead is stiff and light weight; it is one end of the force
train.
Crosshead locks Clamps the crosshead to the columns. The crosshead locks are hydraulically
powered.
Force transducer Measures the axial forces applied to specimen.
Crosshead lifts Raises and lowers the crosshead hydraulically to accommodate different
specimen sizes. The lifts are small hydraulic actuators.
Actuator Applies axial forces to specimens. The actuator is a hydraulically powered
device that provides linear displacement of (or forces into) a specimen. Grips
and fixtures can be mounted to the actuator.
Control panel
Crosshead lift
control
Crosshead locks
Emergency Stop
The Emergency Stop button is standard; the other controls are optional. See
“Lift and Lock Controls” on page 42 for more information.
Controls the crosshead lifts to raise and lower the crosshead hydraulically.
Clamps and unclamps the crosshead to lock it in place or to unlock it so the
crosshead can be repositioned.
Removes hydraulic pressure from the load frame and issues an interlock signal
to the controller to stop the test program.
Servovalve Controls both the flow rate and the direction of fluid entering the actuators. It
determines how fast the actuator extends or retracts.
Manifold Serves as the junction point between the hydraulic power unit (HPU),
accumulators, servovalve, and actuator. The actuator manifold controls the
hydraulic circuit that connects the hydraulic components.
Accumulators Stores hydraulic fluid under pressure to increase the actuator’s response time.
Accumulators also minimize line pressure fluctuations. One accumulator
connects to the pressure line; the other to the return line.
LVDT Measures the displacement of the actuator’s travel. The linear variable
displacement transducer (LVDT) is located inside the actuator.
Isolation pads Dampens the natural frequency to about 20 Hz. Optional air inflated isolators
dampen the frequency to about 2 Hz.