MTS Series 242 Actuators - Manual (Page 34)

Series 242 Actuator Product Information 34
Sideload Calculation Procedure
Operation
where:
S = Actuator stroke (see table)
A = Actuator bearing spacing (see table)
D = Bearing length = 35.8 mm (1.41 in)
E = Bearing area = 42.2 mm (1.66 in)
G = Rod diameter = 28.6 mm (1.12 in)
K = Cyclic sideload = 3.6
3. Divide the actuator bearing load (L) by the actuator area constant (E) to
determine the bearing pressure (V).
where: E = Constant based on actuator bearing area
The maximum allowable bearing pressure (V) is 6.55 MPa (950 psi). If the
value produced by this step exceeds 950 psi, then you will have to select an
actuator with a larger piston rod diameter.
4. Calculate the bending stress placed on the actuator piston rod.
where: G = actuator piston rod diameter
The maximum allowable piston rod stress is 275.8 MPa (40,000 psi). If the
value produced by this step exceeds 40,000 psi, then you will have to select
an actuator with a larger piston rod diameter.
5. If the sideload force is applied to the actuator continuously, then determine
the maximum allowable actuator piston rod velocity for the bearing pressure
(V) calculated in Step 3. This is the highest velocity that the actuator can be
allowed to experience when the current sideload is present.
Use the following equation:
6. If the sideload force is applied to the actuator cyclically (sideload varies
equally through zero), then determine the minimum frequency for the
sideload force. If the test parameters require a lower sideload frequency,
then you will have to select an actuator with a larger piston rod diameter.
L
P S A D C + + + ( ) F B × ( ) +
S A + ( )
---------------------------------------------------------------------- =
bearing pressure (V)
L
E
---- =
Piston Rod Stress
32 P D C + ( ) F B × ( ) + ( )
π G 3 ×
------------------------------------------------------------- =
Maximum Allowable Piston Rod Velocity
5200
V
-------------in/sec =