The AC 156 standard is the go-to method for testing nonstructural components for seismic performance. Nonstructural elements—such as equipment, ceilings, and mechanical systems—are critical for maintaining operational functionality during and after seismic events. The ability to accurately replicate seismic forces through shake table testing ensures that these components perform as intended under real-world earthquake conditions.

The AC 156 standard is widely adopted for evaluating the seismic performance of nonstructural components, such as HVAC systems, lighting fixtures, ceilings, and mechanical equipment. These elements, while not part of the structural frame, are essential for operational continuity during and after seismic events. Accurately replicating seismic forces through shake table testing ensures these components can perform as intended under real-world earthquake conditions.

This blog provides a detailed roadmap covering seismic data access, response spectrum generation, shake table setup, and post-test analysis. The goal is to help professionals meet AC 156 compliance effectively, whether for U.S. or international projects.

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1. Importance of S_D Values for Nonstructural Testing

S_D values represent the short-period design acceleration, evaluated at 0.2 seconds spectral period, and are critical for defining the seismic forces applied to nonstructural components. Accurate S_D values ensure the testing reflects site-specific seismic hazards, aligning with AC 156 requirements.

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2. Tools for Accessing S_D Values in the United States

• ASCE Hazard Tool: Generate seismic design parameters such as S_D for specific U.S. locations by entering project coordinates.
• Seismic Design Maps: A USGS-powered tool offering detailed seismic hazard information for compliance with building codes.

These tools streamline seismic design, ensuring compliance with AC 156 standards for U.S.-based projects.

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3. Finding S_D Values for International Projects

Each region has unique seismic hazard models, making it challenging to obtain accurate S_D values internationally. Below are useful resources for global projects:

• Global Seismic Hazard Map: Provides hazard data for various countries worldwide.

Additionally, QuakeLogic offers custom seismic hazard data for regions such as:

• Turkey
• North Africa
• Central Asia
• Europe

For tailored seismic data, contact us directly. We can provide S_D values, scaled ground motions, and site-specific data.

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4. Ground Motion Selection and Filtering for AC 156 Testing

Ground motion selection is a critical step to ensure the seismic conditions simulated on the shake table accurately reflect site-specific hazards.

• NGA West 2 Database: Access a wide range of unscaled ground motion records. Use filtering tools to select appropriate records based on parameters such as magnitude and fault type.

According to AC 156, both horizontal and vertical seismic forces must be tested separately or simultaneously. The selected motions should meet the Required Response Spectrum (RRS) derived from the building’s location.

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5. Ground Motion Scaling and Spectral Matching

Scaling and matching ground motion to the Test Response Spectrum (TRS) is essential for AC 156 compliance. Key techniques include:

• Time-Domain Matching: Adjusts time history to align with the target spectrum.
• Frequency-Domain Matching: Alters frequency content to match the RRS.

The process ensures the test simulates real seismic forces and meets performance standards required by ASCE 7-22.

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6. Generating a 5% Damped Response Spectrum Using Python

A 5% damped response spectrum is the standard reference for seismic design and testing. We offer a free Python code that generates this spectrum, along with an example for easy implementation. This tool will aid in compliance with AC 156 by ensuring the selected ground motions meet the required spectrum. Please reach us at support@quakelogic.net

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7. Shake Table Setup and Instrumentation Overview

AC 156 requires rigorous shake table testing to certify nonstructural components. Below are key elements for setup:

Shake Tables:

• Electromechanical Tables: For small components.
• Servo-Hydraulic Tables: For larger equipment.
• Portable Bi-Axial Tables: For field applications or lab testing.

Sensors and Instrumentation:

• Accelerometers measure acceleration during shaking.
• Displacement Sensors track movement.
• Strain Gauges monitor internal stress.

The Test Response Spectrum (TRS) measures the actual response of components under seismic forces. TRS must envelop the RRS to ensure the test simulates seismic events accurately.

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8. Post-Test Analysis and Certification

After testing, post-test inspections verify the operational and physical integrity of components. The component must maintain:

• Structural Integrity: Limited yielding allowed, but no significant damage.
• Operational Integrity: Critical components (Ip = 1.5) must function post-test.
• Anchorage Compliance: All mounting systems must remain intact during testing.

Detailed reports documenting setup, results, and performance are essential for certification. Compliance with ASCE 7-22 and FEMA 461 ensures regulatory approval and safety in high-risk seismic zones.

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9. Industry Applications of AC 156

AC 156 is essential for sectors where nonstructural components must remain operational during seismic events, including:

• Healthcare: Hospitals require seismic compliance for life-sustaining equipment.
• Telecommunications: Ensures data centers remain operational post-earthquake.
• Energy and Utilities: Critical systems must withstand seismic forces for safety.
• Nuclear Power: Adheres to IEEE Standard 344 for seismic qualification.

Shake table testing provides confidence that nonstructural components will perform reliably under seismic conditions, minimizing downtime and enhancing safety.

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10. Selecting the Right Shake Table for Your Project

At QuakeLogic, we offer a variety of shake tables designed to meet AC 156 standards:

• Small-scale tables: Ideal for compact nonstructural components.
• Large-scale tables: Capable of simulating higher forces for industrial applications.

Please share your shake table specifications, and we will prepare a custom offer. Reach us at sales@quakelogic.net

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Conclusion

Shake table testing under AC 156 is critical for certifying the seismic performance of nonstructural components. By selecting appropriate ground motions, scaling them accurately, and using advanced instrumentation, you can ensure compliance and operational integrity.

With tools like the ASCE Hazard Tool, Global Seismic Hazard Map, and NGA West 2 Database, we help you meet AC 156 requirements effectively for both domestic and international projects.

As always, “Seeing is Believing”—reach out to us for shake table demonstrations or solutions tailored to your needs.

Selecting the right shake table for research, testing, and educational purposes requires careful consideration of design, performance, longevity, and overall user experience. Both QuakeLogic and Quanser offer bi-axial shake tables, there are key differences that make the QuakeLogic Portable Bi-Axial Shake Table (Servo Motor) the clear choice for clients seeking a superior, user-friendly, and high-performance solution.

Below, we outline the primary advantages that set our equipment (shown on the left) apart from Quanser’s (shown on the right).

1. Higher Operating Frequency and Larger Payload Capacity

QuakeLogic’s biaxial shake table operates at a maximum frequency of 20 Hz, which is double that of Quanser’s biaxial shake table II (10 Hz). This higher frequency allows for a wider range of testing scenarios, especially when high-frequency vibrations or accelerations are involved.

Additionally, our equipment offers a larger payload area of 500×500 mm and a maximum stroke of ±100 mm, enabling the testing of larger and heavier models. Quanser’s smaller payload area (460×460 mm) and smaller stroke (±76.2 mm) limit its capacity to accommodate similar testing scenarios.

QuakeLogic’s shake table has a capacity of 50 kg at 2g peak acceleration simultaneously in both the X and Y directions. In contrast, Quanser’s shake table can only achieve a maximum acceleration of 1.0g in the X direction and 2.5g in the Y direction with a significantly lower payload of 7.5 kg. This makes our shake table far superior in terms of handling larger payloads with higher and more balanced acceleration across both axes. In fact, at 7.5 kg payload our shake table can achieve more than 4 g acceleration in both the X and Y directions.

2. Software Integration: EasyTest Software vs. Third-Party MATLAB Solutions

One of our biaxial shake table’s greatest strengths is the inclusion of its proprietary EasyTest Software, which provides an intuitive, comprehensive interface for operating the shake table. EasyTest is fully integrated with the hardware, meaning there is no need for costly third-party software.

On the other hand, Quanser’s system requires the purchase of MATLAB/Simulink, along with toolboxes to operate the system. This dramatically increases the overall cost and complexity of using the system. QuakeLogic’s system is ready to use out of the box.

3. Durability and Dust Protection

Durability is another area where QuakeLogic’s system excels. Our Portable Bi-Axial Shake Table is equipped with dust covers that protect the internal components from environmental contaminants, extending the system’s operational life. These protective features ensure consistent performance over time, even in challenging environments.

By contrast, Quanser’s shake table has exposed components, including rails, making it more susceptible to dust, debris and falling objects during the testing. Over time, this exposure can degrade the system’s performance and shorten its lifespan, leading to higher maintenance costs and reduced reliability.

4. Remote Control and User-Friendly Operation

The QuakeLogic system is IP-based, allowing for remote control and monitoring—an essential feature for modern testing environments. This flexibility enables users to operate the system remotely, improving the efficiency and convenience of testing workflows.

Furthermore, QuakeLogic’s EasyTest Software ensures that users can quickly set up and conduct tests without needing specialized programming skills or additional training. Quanser’s reliance on MATLAB/Simulink, however, adds an extra layer of complexity and operational difficulty.

5. Aesthetic and Practical Design

QuakeLogic’s Portable Bi-Axial Shake Table boasts a compact, visually appealing design with a dust-protected structure, making it ideal for educational and research labs. In contrast, Quanser’s system, with its exposed components, is not only less visually appealing but also less practical in terms of maintenance and long-term durability. QuakeLogic’s polished and professional appearance reflects the advanced engineering inside, making it the better option for clients who value both form and function.

6. Comparing Technical Specifications

When comparing the technical specifications of QuakeLogic’s shake table with those of Quanser’s, the differences are striking:

Feature	Quanser Biaxial Shake Table II	QuakeLogic Portable Bi-Axial Shake Table
Dimensions	610 x 460 mm x 130 mm	800 x 800 x 225 mm
Total Weight	27.2 kg	78 kg
Top Stage Dimensions	460 x 460 mm	500 x 500 mm
Maximum Travel (Stroke)	±76.2 mm	±100 mm
Maximum Acceleration	2.5 g with 7.5 kg payload	±2 g with 50 kg payload ±1 g with 100 kg payload
Maximum Velocity	399 mm/s	1,000 mm/s
Operational Bandwidth (Frequency)	10 Hz	20 Hz

8. Conclusion: A Superior and Cost-Effective Solution

In comparing the QuakeLogic Portable Bi-Axial Shake Table with the Quanser Biaxial Shake Table II, QuakeLogic’s advantages are evident. With a specifically engineered bi-axial design, integrated EasyTest software, superior mechanical components, dust protection, and greater operational frequency and payload capacity, our system delivers a high-performance yet cost-effective solution.

Clients such as NOKIA-BELLS-LAB have praised the ease of setup and exceptional performance of our shake table. The EasyTest software stands out for its intuitive design, allowing users to focus on testing rather than on lengthy configurations or troubleshooting.

For anyone in need of a reliable, easy-to-use shake table that minimizes setup time and maximizes operational efficiency, QuakeLogic’s Portable Bi-Axial Shake Table is the ideal choice. Its seamless user experience and long-term reliability make it perfect for research institutions, universities, and industries dedicated to seismic and vibration analysis.

To learn about our biaxial shake table, please visit the product page HERE.

Reference:

Technical specifications for the Quanser Shake Table II were sourced from the official Quanser website.