SOW JSC High Force EVTS 2022.pdf

STATEMENT OF WORK

HIGH-FORCE ELECTRODYNAMIC VIBRATION TEST SYSTEM

1.0 INTRODUCTION

This Statement of Work (SOW) describes the requirement of a high-force Electrodynamic Vibration Test System (EVTS) to be provided to the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) in Houston, Texas. This EVTS will be used to perform vibration or mechanical shock with sinusoidal, random, or transient input signal excitation in either the vertical or horizontal direction. Specifically, this SOW is seeking the maximum EVTS performance available on the commercial off-the-shelf market to meet flight environments of large spacecraft and spacecraft components. The vendor shall also provide a turnkey reliable and proven EVTS to meet the following defined requirements, along with on-site utilization services, including, system functional checkout and system operation training. The vendor shall demonstrate prior track record of providing similar EVTS that are currently in operation and have been proven to be reliable.

2.0 SYSTEM PERFORMANCE REQUIREMENTS

2.1 MAJOR COMPONENTS

The vendor shall provide a complete reliable and proven turnkey system ready to be utilized with the following major components.

An electrodynamic shaker with its cooling system An air-cooled amplifier and DC current supply to provide the excitation and control of the shaker

A slip table for testing in the horizontal directions.

2.2 TECHNICAL REQUIREMENTS

The vendor shall provide an EVTS that meets the requirements defined in the following sections. Whenever applicable, the vendor shall provide data demonstrating that their proposed system meets the defined requirements.

2.2.1 Test Requirements

The EVTS shall be capable of performing sinusoidal, random vibration, and shock tests with the following minimum requirements.

TEST TYPE ELEMENT REQUIREMENT

Sinusoidal Test Frequency Range 5.0 - 2,500 Hz

Rated Force 55,000 lbf peak

Max Acceleration 130 g-peak on base table

Max Velocity 80 inches/second

Random Test Frequency Range 5.0 - 2,500 Hz

Rated Force 55,000 lbf RMS (based on flat spectrum with 1000 lbs payload)

Max Acceleration 100 g-RMS with 10 lb. test article ISO 5344 Spectral Density

Shock Test Frequency Range 5.0 - 5,000 Hz

Rated Force 100,000 lbf half sine peak shock

2.2.2 Shaker Requirements

ELEMENT REQUIREMENT

Armature Type Induction Ring Concept without Electrical or Fluid Connections in the Moving Parts to Reduce Maintenance

Armature Minimum Load Capacity 4,000 lbs without external support device

Armature Minimum Displacement 3-inch peak-to-peak continuous

Armature Fundamental Resonance 1,700 Hz minimum (unloaded)

Armature Weight 400 lbs maximum

Armature Overall Diameter 25 inches minimum

Armature Table Mounting Replaceable Stainless Steel free-running raised inserts ½ “ - 20 UNF.

Armature Table Bolt Pattern 1 bolt at center of armature head 4 bolts at 4” diameters of armature head 8 bolts each at 8”, 12”, 16”, 20” and 24” diameters of armature head

Cross-Axis Motion At a 0.5-inch peak-peak displacement or 10g acceleration (whichever is less) between 15 and 2000 Hz, the cross-axis motion measured on the thrust center line parallel or perpendicular to the shaker trunnions shall not exceed 10%. Small exception at limited number of points can be acceptable.

Armature Table Tolerance Flatness shall be within +/- 0.005 inch.

Armature Positioning Shall be equipped with automated re-centering system when loaded without operator intervention.

Stray Magnetic Field Less than 20 gausses at 6 inch above the table mounting surface.

Shaker Operation Shaker shall be able to operate in vertical or horizontal orientations

Shaker Configuration Mechanism Shaker shall be equipment with a mechanism to rotate it from vertical to horizontal orientation by a single operator in around 10 minutes

Shaker Configuration and Isolation Shaker and slip table shall be mounted on a single base and shall be isolated from the floor with a resonance frequency of less than 5 Hz

Shaker Head Expander The acquisition of a shaker head expander is not included in this SOW but the shaker shall be able to accommodate a head expander with guidance bearings and load support.

Drive Power Cables 75 ft. minimum (distance between power amplifier and shaker unit)

2.2.3 Power Amplifier Requirements

Power Source The amplifier must provide its own internal circuit breaker for lockout capability. The amplifier shall have its own power distribution so that it can provide power to all EVTS components (system has only one power connection to the facility). Exceptions can be made on isolated EVTS components to meet electrical code. A separate disconnect is required for each major component.

Input Signal The amplifier input shall accept full scale voltage level of 2.5 Vrms or less into 10K ohms impedance for full output.

Output

Requirement

Output load connections shall be isolated from ground. At a minimum, the power output shall be capable to drive the shaker to the levels defined in Section 2.2.1.

Frequency Range: 20 to 2,000 Hz at full rating.

Signal Noise Ratio: Shall be -60 dB or less at full rating with input shorted.

Connection The amplifier must be directly connected to the shaker without matching transformer.

Cooling The amplifier must be totally air cooled

Racks All electronics equipment shall be housed in standard electronic equipment racks.

Future Expansion The amplifier shall be expandable to accommodate future greater capabilities or additional shakers.

Maximum Noise 85 dBA maximum running at full power capacity measured at 2 meters away.

Energy Efficient Energy saving provision is desirable

2.2.4 Shaker Cooling Unit Requirements

Water-Cooling and Chilled Unit Cooling unit shall provide sufficient cooling to the EVTS to drive it at full rating without damaging any of its components.

Inter connection Hoses Length of water hoses shall be at least 75 ft. from cooling unit to the shaker

Blower Duct If a blower is provided, the duct length shall be at least 20 ft.

Racks All cooling equipment shall be housed in standard equipment racks.

2.2.5 Horizontal Slip Table

Slip Table Plate Size Shall be minimum 60 inches by 60 inches of magnesium slip plate.

Slip Table Type Shall have linear guide bearings (minimum of 4 bearings).

Slip Table Minimum Moment 600k in-lbf

Slip Table Plate Bolt Pattern Shall have a 2-inch grid pattern with tap-lock inserts 3/8”-24UNF by

1.0” deep minimum. Helicoil inserts are not acceptable.

Slip Table Plate Tolerance Flatness shall be within +/- 0.005 inch

Slip Table Plate Support Shall be supported on a natural granite bearing surface and its flatness shall be within +/- 0.005 inch

Slip Table Attachment Shall be compatible with armature Table Bolt Pattern defined in Section 2.2.2.

Effective Travel Shall be no less than the minimum armature displacement defined in

Section 2.2.2.

Usable Frequency Range 5.0 – 2,000 Hz minimum

Minimum Weight Capacity 4,000 lbf. without external support device

Hydraulic Supply Shall be provided to drive the slip plate up to 300 psi maximum.

Interconnection Hoses Length of hydraulic hoses to shaker shall be at least 40 feet if hydraulic unit is not integrated in the slip table base.

Shaker Configuration and Isolation Shaker and slip table shall be mounted on a single base and shall be isolated from the floor with a resonance frequency of less than 5 Hz

2.2.6 Safety Protective Devices

At a minimum, the system shall have protective devices (with LED indicator when applicable) against the following failures or conditions to provide fail-safe operations of the system:

Emergency shut-down button

Shaker over-travel

Shaker stator over-temperature

Shaker field coil over-temperature

Field under voltage / current only

Peak current over-limit and rms current over-limit

Amplifier over-temperature

Amplifier equipment bay door open

Slip-table system failure

If a heat exchanger is supplied for amplifier or shaker cooling the following interlocks shall be provided:

Outer-loop water pressure

Coolant pressure

Coolant flow rate

Coolant contamination

2.2.7 Switching Panel Control

The amplifier control panel shall include all the switches, indicators, and adjustments to enable control of the EVTS. As a minimum, the control panel shall include the following:

Be designed to operate from a local panel or a remote panel. The remote panel shall include all functions of the local panel. Operation from either the local or remote panel shall be selectable and the unused panel shall be automatically locked out. If a remote panel is not provided or purchased, the system shall provide the option of adding it in the future.

Provide an auto-start function that would enable the amplifier to be brought from an off state to a full operational state with a single remote contact closure.

Provide indication when the system is ready for operations.

Provide overall gain control of the amplifier.

Provide front panel adjustable limits for the over-voltage and over-current interlocks.

Provide readouts of input DC voltage and current.

Provide readout of output AC voltage and current.

Provide a visual indication of the state of the system.

Provide visual indicators on the type of system or component failures or interlock violations.

Provide a soft start interval of no more than 500 milliseconds between off state and application of full line voltage to minimize shocking of power amplifier components.

Shall automatically sense the operational mode, i.e., sine or random, and automatically adjust the amplifier parameters for optimum performance in the operating mode. No manual reconnections shall be required for operation in sine, random, or transient mode.

3.0 SITE SPECIFICATION

3.1 UTILITIES

The EVTS shall be capable to operate within the following site utility capabilities.

Electrical: 480 V, 60 Hz, 3 Phases Compressed Air: 120 psig Chilled Water: 100 psig; Around 45oF

3.2 ENVIRONMENTAL CONDITIONS

The system shall be operable at rated performance in any orientation under single or combined environmental conditions of temperature and humidity specified below:

Temperature 50 to 80°F

Humidity 15 to 75% relative humidity

Rated electromagnetic interference shall be within the limits specified for industrial devices.

4.0 OPERATING MANUALS

Two copies of Operating and Service Instructions shall be supplied. Electronic media on compact disk in common format, such as MS office or Adobe Acrobat is acceptable. As a minimum, the operating manual shall include the following sections:

Nomenclature

Description of equipment

Principles and methods of operation

Performance curves

Diagram of service connections

Cabling diagram

Inspection and maintenance schedules and procedures.

Assembly and disassembly procedures

List of special tools

Preferred list of spare parts

Acceptance test report

5.0 WARRANTY

The system shall be covered by warranty on material and workmanship for a minimum period of one year from in-service date.

6.0 DELIVERY SCHEDULE

The complete system shall be delivered to NASA-JSC (Houston, Texas) no later than 18 months after the order has been placed.

7.0 INSTALLATION

Installation responsibility is defined as follows:

The vendor shall provide all cables, hoses, and interface connections. Hoses and cable lengths are defined in previous sections.

The vendor shall specify detailed installation requirement and documentation no later than 8 weeks after contract award. As a minimum, the following information shall be provided:

• Electrical circuit breaker requirements for each EVTS component

• Interface and connection requirements between EVTS and facility

• Precise dimensions of each EVTS components with footprint layout

• Connection definitions and details between EVTS components

• Overall EVTS layout options

• Detailed part list

NASA-JSC shall be responsible for the installation of the entire EVTS per vendor directions and documentation. Vendor shall provide telephone or electronic correspondence support during the installation process.

8.0 ACCEPTANCE

The vendor shall perform acceptance tests to demonstrate compliance with the requirements of this statement of work and to demonstrate there are no manufacturing defects. The vendor response to this statement of work should include a description of the acceptance tests to be performed. The acceptance tests may be performed at the vendor facitlity or at NASA-JSC. The accceptance tests may be observed by a NASA-JSC representative.

9.0 TRAINING

The vendor shall provide a minimum of one day on-site hands-on training at NASA-JSC.