Design for dynamic stability

How to ensure that a product will fulfill its dynamics and vibration requirements. From specification to actual design; what is the right approach?

One of the challenges in product or system design is to fulfill dynamics and vibration requirements. For instance, if your system needs to be highly accurate, vibrations from internal sources (e.g. motion stages) or from external sources (e.g. sound, floor vibration, other machinery) may disturb your accurate production or measurement process.

In other applications, your product may intentionally need vibrational behavior, while the user should not feel that vibration and the product must withstand the induced fatigue loading. Your product or system may also be exposed to harsh vibration disturbances like in rotary machinery or transport systems, while sound and vibration levels perceived by the process or the user must be below certain levels.

Solution: include dynamic computations in all phases of the design

For optimal solutions, it is important to include dynamic computations in all phases of the design. To be efficient, different modeling techniques are used for each phase, with different levels of detail and different focus. Also, relevant influences (external and internal) affecting the performance have to be considered.

How we can help you with design for dynamic stability

We have ample experience in designing systems and products that meet specific vibration requirements for various applications. Thereby, dynamic behavior is considered to be of key importance in system architectural choices, as well as in specific design choices. Our system architects, dynamics experts and mechanical designers use different modeling techniques to predict dynamic behavior during the design, as to meet requirements by design first time right.

The flexibility you need

We can help you to make the right design decisions and evaluate architectural concepts for dynamic performance.

• That can be in the form of expert consultancy
• By involving our specialists and designers in your development team or
• By outsourcing your design challenge to our multi-disciplinary mechatronics design group

We can help you with:

• Selection of system concepts for high-precision (nanometer accuracy) motion stages using lumped mass modeling (1D – 2D mass spring systems including servo control loops).
• Component optimization to realize minimum eigenfrequency using Finite Element analysis (modal analysis).
• Compliant sensor design in domestic robot design for robust force feedback, using 2D rigid body models including force feedback loop simulations.
• Vibration isolation system design with good compliance and isolation behavior for vibration sensitive applications with varying payload forces. (RockSolid).
• Application of visco-elastic material to incorporate passive damping in high precision equipment, using in-house test-rig for qualification of visco-elastic material properties up to 1 kHz.
• Leaf spring optimization to reduce fatigue stress loading in a resonating actuator for a consumer product by combining 1D lumped mass models for dynamic analysis with Finite Element models for stress analysis.
• Introduction of acoustic shortcuts in mechanical design to cope with vibro-acoustic coupling in high-precision motion stages, using Finite Element modeling and model reduction techniques for fast design iterations.
• Prediction of image quality of a healthcare imaging system to specify construction stiffness, using rigid body models and quantitative models for vibration disturbance inputs.
• Cooling circuit optimization (hose stiffness and geometry) to minimize fluid dynamics excitation for fast moving motion stages leading to reduced dynamic stability of nanometer positioning stages.

Performing thorough and sensible dynamic measurements is more than just knowing which sensors to use and appropriate equipment. It’s also about insight and knowledge of the object, not just about how to measure, but also about what to measure.

The info you have determines your conclusion. With some additional information, a bag turns out to be a mug. Similarly, when performing a modal analysis, it is important to measure all relevant parts of an object. Missing a crucial part (the hand in the picture!) may result in misunderstanding the mode-shape and can lead to wrong conclusions.