Introduction

Vibration testing is essential in aerospace, automotive, and electronics industries to verify product durability, identify design flaws, and ensure compliance with standards like MIL-STD-810 or ISO 16063. In this article, we guide you through building a complete vibration test system using a shaker, accelerometers, and National Instruments Sound & Vibration modules integrated with LabVIEW.

What Is a Vibration Test System?

A typical vibration test system subjects a unit under test (UUT) to controlled oscillatory motion over a defined frequency range and acceleration profile. The system includes:

• Shaker: Electrodynamic or servo-hydraulic actuator to apply vibration
• Power amplifier: Drives the shaker with sine/random signals
• Accelerometers: Sensing devices mounted on the UUT
• DAQ modules: Acquire signals from sensors and provide control feedback
• Software: Control interface and data logger (usually LabVIEW)

The system supports both development and qualification testing across vibration profiles like sine sweep, random, and resonance search & dwell.

Choosing a Shaker

Electrodynamic shakers are preferred for frequencies from 5 Hz to 5–10 kHz and accelerations up to 100 g. Key parameters include:

• Peak force rating: Typically 100–10,000 lbf
• Frequency range: Must match your application (e.g., 10–2,000 Hz for automotive)
• Payload mass and mounting: UUT must not exceed shaker specs

Cooling (air or water) and vibration tables (slip table for 3-axis testing) may be needed depending on your test plan.

Sensor and Signal Conditioning

Accelerometers are typically IEPE (ICP-type) or charge mode devices. For compatibility with NI modules, ensure:

• IEPE sensors: Connect directly to NI Sound & Vibration modules (e.g., NI 9234, NI 9232)
• Charge mode sensors: Require a charge amplifier or external conditioning
• Signal cables: Must be low-noise and short to avoid signal degradation

NI Sound and Vibration modules offer built-in IEPE excitation and anti-aliasing filters. See the Electronic Test & Instrumentation section for relevant products.

DAQ and Control Hardware

The key to high-fidelity vibration measurement lies in synchronized data acquisition. Recommended options include:

• NI PXI Platform: For multi-channel, high-speed (102.4 kS/s) sampling across axes
• CompactDAQ (cDAQ): For portable or mid-range setups
• Real-Time Controllers: For closed-loop feedback and real-time test execution

Explore PXI Platform or CompactDAQ for scalable options based on your test complexity.

LabVIEW-Based Vibration Control

With LabVIEW and the Sound and Vibration Toolkit, you can:

• Generate excitation signals (sine, random, shock)
• Control the shaker via feedback loop from accelerometers
• Perform real-time FFT and power spectral density (PSD) analysis
• Log test data and generate automatic test reports

LabVIEW’s flexible GUI and modular architecture allow tailored test interfaces, profile import/export, and result post-processing.

Common Test Applications

• Automotive: Engine-mounted components, battery modules, infotainment systems
• Aerospace: Satellite components, avionics, flight hardware
• Consumer electronics: Vibration fatigue, resonance testing, drop simulation
• Defense: Environmental stress screening (ESS)

FAQs: Vibration Testing with NI Tools

Can I run sine and random profiles in LabVIEW?

Yes. The Sound & Vibration Toolkit supports user-defined test profiles, real-time output, and data acquisition.

What’s the best DAQ module for vibration?

NI 9234 and NI 9232 (IEPE) are common for accelerometer-based testing. PXIe-449x series offers high-density configurations.

How do I synchronize data across channels?

Use PXI hardware with NI-TClk or cDAQ chassis with shared timing engines for phase alignment.

Conclusion

A well-integrated vibration test system provides reliable insights into mechanical durability and product performance. By combining a shaker, high-quality sensors, and National Instruments DAQ with LabVIEW software, engineers can build scalable, precise, and standards-compliant testing environments. Explore the Electronic Test & Instrumentation and PXI Platform sections to start building your setup today.