Driving Better Design and Validation Through Modal Analysis
Modal analysis shows how energy moves through a structure. It bridges the gap between simulation and reality, showing whether the model truly reflects how the system, subsystem, or structure reacts.
Understanding the True Dynamics of Your Design
Today’s equipment is a complex integration of subsystems and components sourced from diverse suppliers — each with unique manufacturing specifications. When vibration from one subsystem resonates through another, it can trigger unexpected failures, leading to unplanned downtime, excessive warranty claims, and unrecoverable costs.
Without the right diagnostic tools, identifying the root cause of these issues can feel like a guessing game.
At Six D Testing & Analysis, we remove the guesswork. Through modal testing, we help engineers uncover the dynamic behavior of their systems, revealing how and why structures vibrate, deform, or fail under real-world conditions.
What Is Modal Testing?
Modal Testing is the process of identifying a structure’s inherent dynamic characteristics, its natural frequencies, mode shapes, and damping factors.
These parameters describe how a system responds to vibration and excitation. By collecting this data, Six D creates mathematical models that represent the true dynamic behavior of your product.
Armed with these insights, engineers can make informed design decisions, optimize stiffness and damping, and prevent vibration-related failures before they occur.
Applications include:
- Troubleshooting field vibration or noise issues
- Correlating test data with simulation or FEA models
- Validating next-generation or enhanced product designs
- Supporting NVH, fatigue, and durability investigations
Seeing What Others Can’t
Every component, from a vehicle subframe to a turbine blade, has its own vibration “fingerprint.” When excited by an external force, it responds at specific frequencies and shapes known as modes. If one of these modes aligns with the system’s operating frequency, resonance occurs, amplifying vibration, accelerating fatigue, and compromising reliability.
Modal testing makes those hidden dynamics visible. Using precision sensors, impact hammers, and shakers, Six D engineers measure how your structure reacts to controlled excitation. From these tests, we extract frequency response functions (FRFs) that quantify energy flow and identify weak links in your design.
Modal Testing Techniques at Six D
Impact – Bump
6D offers comprehensive engineering solutions, including impact testing and bump testing. Impact testing involves subjecting specimens to controlled impact forces or impacts from to measure their response. Bump testing is a valuable technique employed to evaluate the structural integrity and performance of products or systems when subjected to sudden mechanical shocks or bumps, sometimes during operation. The response is analyzed to study mode shapes, natural frequencies, damping factors, etc.
Shaker
6D provides shaker testing by partnering with local test labs as well as through some in-house capabilities. Shaker testing is a highly effective method for subjecting products and components to controlled vibrations to evaluate their structural integrity, performance, and reliability. By simulating real-world vibration conditions, such as those experienced during transportation or operational use, shaker testing helps identify potential weaknesses, resonances, or durability issues.
Pull – Step Relaxation
This technique involves incrementally applying a sudden load or strain step to a structure or component and allowing it to relax over a series of time steps. Step relaxation analysis helps engineers understand how materials respond to sudden changes in load, allowing them to assess factors such as stress redistribution, creep, and relaxation effects. 6D assists clients in predicting and optimizing the long-term behavior and performance of their products, using step relaxation tests.
From Test Data to Digital Correlation
Modal test results are most powerful when connected to simulation. Six D specializes in test-to-model correlation, aligning measured modal parameters with FEA predictions. This process refines assumptions about mass, stiffness, and damping, leading to simulations that more accurately predict real-world behavior.
This capability also supports digital twin development, where live test data continually informs and updates simulation models, enabling predictive maintenance and ongoing performance optimization.
Ready to See What Your Structure Is Saying?
If vibration, fatigue, or NVH issues are impacting your product’s performance, modal testing is the place to start. Six D Testing & Analysis helps you visualize your product’s true dynamic behavior, turning complex vibration data into actionable insights that improve durability, reliability, and customer satisfaction.
- Use the form below request a call to discuss your modal testing or structural dynamics needs.
- Go here to request our free guide: “An Engineer’s Guide to Experimental Modal Analysis”