Large-scale, high-performance dynamic and static actuators, providing
the ability to conduct dynamic, pseudo-dynamic, hybrid pseudo-dynamic
testing.
The actuators and associated control systems will allow for the
development of new testing methodologies, including the effective
force control testing method, in which large structures could be
directly subjected to dynamic excitations without the need for shake
tables.
A large reaction wall, built next to the shake tables and equipped
with dynamic actuators, will allow for the application of computer-predicted
external forces on shake table-mounted substructures, thus simulating
the reaction of the entire structure (Real-Time Dynamic Hybrid Testing,
or RTDHT).
Equipment required to operate the actuators, including a high-capacity,
high-performance hydraulic supply and distribution system (up to
1600 gpm), and numerous digital control systems.
Networked tele-experimentation capabilities using modular and expandable
teleobservation and teleoperation equipment, tied to the testing
systems using discrete and global sensors, including high-resolution
digital video and imaging capabilities.
Real Time Structural System Specifications:
A. Dynamic Actuator Assemblies (Quantity 3 sets)
244.51S 100 Ton Dynamic Actuator Assembly
Linear Hydraulic Actuator
Dynamically Rated for high performance testing.
100 tons static rated, 90 tons dynamic rated.
Double acting (hydraulic pressure on both sides of the equal area
piston)
LVDT type full stroke coaxially mounted displacement transducer
Polymeric bearings for low friction and high side load capability
Double amplitude displacement, 40 inches, +/- 20 inches (Note
that these long stroke actuators will have low natural frequencies)
Rubber rest pads to protect actuator and floor during storage
Lifting shackles
Swivel Head Assembly, MTS Model 249.51
Rated force capacity, ± 100 tons
Adjustable bearing clearance to minimize backlash
Tilt angle ±8 °
Swivel angle +90 °, -30°
Swivel Base Assembly, MTS Model 249.51
Rated force capacity, ± 100 tons
Adjustable bearing clearance to minimize backlash
Tilt angle ±8°
Swivel angle +90 °, -30 °
Hydraulic Servovalve Assembly
There is also MTS 256.80S three stage servovalve for this application.
This valve is rated in excess of 3000 LPM and will provide the ability
to run demanding earthquake records for real time hybrid applications.
A load of approximately 150 kips (70 tons) can be achieved at 1
meter/second velocity condition with this valve assembly.
Additionally, a custom port shut off valve assembly and a second
low flow servovalve manifold with a conventional MTS 252.25 (57
LPM) servovalve and port shut off. This will allow either high flow
or low flow operation with the actuators. The port shut off valves
requires a manual operation and the operator must also switch the
valve electronic cables to move from one configuration to the other.
Load Cell, MTS Model 661.31E-01
Rated at ± 100 tons force capacity
Single bridge
150% static load capacity
1 x 109 cycles fatigue at ±75% of rated load
Combined accuracy of load cell and transducer conditioner of 0.5%
of range for loads between 0% and 100% of calibrated range.
B. Static Actuator Assemblies (Quantity 2 sets)
243.90T Linear Hydraulic Actuator
Recommended for static applications.
Standard Rated force capacity: 446 kip Tension / 600 kip Compression,
but for this application, MTS will include a load limiting valve
on the compression side limiting it to 446 kips tension/446 kips
compression allowing for matched size pivot head and base.
Single ended (piston rod extends from front end of the unequal
area piston)
Double acting (hydraulic pressure on both sides of the unequal
area piston)
Full stroke coaxially mounted Temposonics II displacement transducer
High quality, non-metallic bearings provide long life and resist
bearing-to-rod galling failures
Rubber rest pads to protect actuator and floor during storage
Compression Relief Valve - Factory set pressure relief valve limits
compressive force to 446 kip to allow MTS 243.80 pivot head and
base assemblies rated at +/- 446 kips to be used.
Allows selection of lower capacity swivels and load cell when
maximum compression of actuator is not required
Located on the servovalve manifold
243.80 Pivot Head Assembly
Rated force capacity: ± 446 kip
Swivel angle: + 90°, - 80°
Not for use on cyclic, reversing load applications.
243.80 Pivot Base Assembly
Rated force capacity: ± 446 kip
Swivel angle: + 90°, - 80°
Not for use on cyclic, reversing load applications.
Servovalve Manifold Assembly for 252.25 Servovalve
Servovalve manifold with dual servovalve mounting capability (one
valve included). Cover plate over unused valve ports.
Two stage, four way operation
Four port valve.
Requires two stage valve driver
One MTS 252.25 Servovalve, 15 gpm included.
660.23 Differential Pressure Cell
Used for load control or readout in the absence of a load cell.
Includes protection manifold to eliminate damage due to pressure
spikes.
C. Hydraulic Power Supply Subsystem
MTS Model 506.92 HPS (quantity =4)
Rated at 185 gpm (700 lpm) at 3,000 psi (207 bar) each.
High Flow Hydraulic Distribution Manifolds (qty 4 locations)
Four high flow hydraulic distribution manifolds that will each
allow a high flow actuator running 800 GPM valves to be connected
through it’s 800 gpm Hydraulic service Manifold. These manifolds
will be located on the strong floor area. These manifolds will each
have four, four bolt flange ports with independent manual shut off
valves to allow the four 2 inch hose sets to be attached simultaneously
for the 800 GPM servovalve performance actuators.
Hydraulic Distribution Outlet Manifolds (qty 3 total)
Three Hydraulic distribution Outlet stations with 2 sets of ball
and check valves will be provided near the south end of the strong
floor feeding from the 50 mm diameter piping system.
Custom 800 gpm Hydraulic Service manifolds (qty 3 total)
Three, High flow HSM’s, one for each high flow actuator will be
provided with 40 gallons each of pressure and return accumulation.
Each manifold will have pilot pressure on, low flow low pressure,
and a high flow high pressure electronically switchable states and
can control one high flow actuator configured with an 800 GPM valve.
One subtle feature of these custom manifolds is that the pressure
and return line accumulators are always active when connected to
the distribution system providing additional accumulation throughout
the distribution system.
MTS 293.12 Low Flow Hydraulic Service Manifold (qty 2)
Two HSM’s with single station control will be provided.
Each HSM allows turning off pressure to an actuator without shutting
down the HPU. These would be used for the MTS 243 static actuators.
Hydraulic ramp (low to high and high to low) reduces shock
to specimen, provides pressure regulation, reduces the chance of
specimen damage, and increases the life of the hydraulic components.
Local accumulators protect the hydraulic lines from pressure
spikes and reduce flow fluctuations resulting from changing system
demands. (1 gallon pressure and 1 quart return line accumulators)
10 micron main filtration
Servovalve controllers for low flow services MTS 407 (5 sets)
Miscellaneous Piping, Manifolds, fitting, etc. to integrate the
structural components to the main hardline system.
The hydraulic distribution system will be designed to meet an oil
filtration quality of ISO 13/10. This level of cleanliness is critical
for high fidelity servovalve systems.
Cable-stayed bridge
segment with RTDHT using two shake tables, reaction walls, and
large-scale high performance actuators.
Real-time hybrid seismic testing system (Substructure
dynamic testing)
