Providing Vibration And Acoustic Consulting Services Since 1984
Response Dynamics works within the United States and worldwide as acoustic and vibration consultants, providing unmatched services in advanced vibration analysis, including acoustic analysis, vibration testing, acoustic testing, vibration monitoring and noise monitoring services, as well as engineering design. For over 40 years, we have combined our engineering expertise in vibration testing, acoustic noise, strain, thermal heat flow, airflow, and magnetic fields. We utilize our specialized knowledge and skills to work with and be a part of our clients' teams. Please feel free to call us to discuss your team's product, system, or facility issues.
We have worked on a myriad of systems and facilities, with responses ranging from subnanometer-amplitude disturbances of electron microscopes, interferometers, and atomic force microscopes, to micron-amplitude motions of giant telescopes in Hawaii and the Chilean Andes, to meter-amplitude storm responses of offshore oil rigs, to name just a few. (See our Client list by industry.)
Industries and Projects Spanning 9 Orders of Magnitude
Semiconductor
Electron Microscopes
Telescopes
Optical Systems
Offshore Facilities
Working in the roles of vibration consultant, acoustic consultant, and EMF consultant, we partner with R&D teams on the design and development of hundreds of critical systems, products, and facilities.
We have worked on hundreds of systems and facilities for high-tech and heavy industry.
High Tech Industries include:
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Semiconductor
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Biotechnology
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Pharmaceutical
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Nanotechnology
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Medical Device
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Communication
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Aerospace and Defense
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Electric & Hybrid Vehicles
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Power Generation & Alternative Energy Systems
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Scientific Research
Heavy Industry Consulting include:
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Transportation
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Power Generation
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Food Industry
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Automotive
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Paper
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Mining
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Oil
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Agriculture
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Construction
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Other industries
We characterize complex (often multivariable) problems, design tests to diagnose the root cause of the issue, and provide engineered solutions (see Industries).
Vibration problems and acoustic noise problems can be very complex and subtle. As a result, it is often our role as the consultant to perform vibration analysis, vibration testing, acoustic analysis, and acoustic testing to develop an understanding of the problem and provide a means for the rest of the design team to directly visualize the problem, whether it is the vibration deformation mode shapes associated with problematic resonances or the distribution of acoustic noise power radiating from a complex product.
Once the design team can visualize the problem, developing the solution becomes much more straightforward. It is a little like the children's party game of pin-the-tail-on-the-donkey; our job, as the Vibration Consultant or Acoustic Noise Consultant, is to take the blindfold off the design team so that they can easily hit the target, instead of using the frustrating, time-consuming, and expensive trial-and-error process that the team had been struggling with when blindfolded.
Diagnostic Testing
Response Dynamics has made Diagnostic Vibration Testing and Diagnostic Acoustic Testing our bread-and-butter work for more than 30 years. We enjoy this work, and we do it well because we are well grounded in basic applied physics, digital signal processing, structural dynamics, and vibro-acoustics, as well as how they relate to system and facility vibration and acoustic noise issues on a myriad of levels.
We are expert vibration consultants in resonance testing, Modal Analysis, Operating Deflection Shape Testing (ODS), as well as both Steady State and Transient Analysis, with literally decades of experience developing our detailed methodologies that produce meaningful results.
Fundamental to Dynamic Testing are Frequency Response Functions (FRFs). As Vibration Consultants and Acoustic Consultants, we design tests and/or analyze frequency response functions (FRFs) almost daily. These FRF measurements form the basis of modal analysis and the theory of linear system structural dynamics. We are fluent in spectral analysis and the digital signal processing inherent in the vibration analysis measurement process, and thus we can spot problems before they corrupt a whole data set or an entire project.
Tools of the Trade for Structural Dynamics Testing
Nonlinearities exist in all physical structures and are often not a problem. However, when they are involved, we know how to spot them and deal with these unique dynamics. While performing vibration testing, the choice to use electromagnetic shakers, force hammers, or known inertial loads as force inputs depends on the nature of the system dynamics, the response amplitudes, and the transient/steady-state characteristics of the vibration issue. We have refined these vibration consulting skills for more than 30 years.
The physical principles of structural dynamics, acoustics, optics, and thermodynamics apply to structures and systems large and small. The wide variety of our projects keeps our work interesting, even after all these years, as we apply the same fundamentals again and again.
Meaningful Test Data, Knowing Good Data From Bad
We use our vibration testing and noise testing expertise, as well as various methods of analytical and computer modeling and Finite Element Analysis (FEA), to make sense of complex vibration and noise problems, thereby enabling efficient solutions.
Strain Gage Testing and Stress Analysis of Fan Blade for FEA Validation
The nuts and bolts of knowing good data from bad brings indispensable value to our analyses.
We also make an effort to know what we don't know by considering measurement error, instrumentation noise, resolution limitations, and nonlinear behaviors. See our discussion on Product R&D.
120 Megawatt Steam Turbine, Concrete Turbine Pedestal, and Steel Building Structure, Using Thermal Analysis and Operating Deflection Shape Testing (ODS)
Semiconductor Inspection Tool Testing Using Sub-Nanometer Capacitive Sensor Between Wafer and Optics Plate
The limitations of where instrumentation can be placed, the inherent sensor limitations, and the impact on system dynamics need to be considered. Thus, designing the experimental setup to extract meaningful vibration analysis and acoustic analysis results is perhaps the most important step in solving a pressing issue where time, patience, and resources are in short supply.
We most often characterize a problem first, work from known conditions, and stay within "the known" as we proceed, making sense of what we observe as we move forward. This is very important. We test and analyze the changes in dynamics we are trying to create in real time, on-site, and often make changes to our experimental test plan on the fly as we discover how a system is actually behaving. In doing so, we often get meaningful results from which we can make sound engineering decisions in a short time frame. We do NOT make measurements and spit out data.
We are experienced in vibration testing and acoustic noise testing instrumentation, digital signal processing, and spectral analysis. As Vibration Consultants and Acoustic Consultants, we use our specialized skill set and a vast selection of instrumentation that we have collected for over three decades to design tests and solve complex problems.
Multi-Variable Testing
Multivariable testing is usually necessary to really get a handle on an issue involving multiple disciplines of physics. We design tests to measure static and dynamic strain, acoustic noise, static and dynamic pressure, vibration acceleration, velocity and displacement, magnetic fields, temperature, fluid flow, and light intensity, to name a few.
Real-world problems involving the measurement of multiple variables require an understanding of the physics of the coupling between them, as well as the physics and limitations of the measurement instrumentation. Problems in different frequency ranges necessitate unique approaches involving instrument selection, mounting dynamics, cabling, and coupling with other structures and media.
Multi-variable testing
Measurements of ambient acoustic noise, floor vibration, and the frequency response of the semiconductor tool response showing resonances that dictate the disturbance response of the tool to the environment
For instance, when a consumer product is too noisy, such as a bedside medical device, thermal analysis and heat flow optimization of the cooling system will often be part of the acoustic solution, in addition to acoustic analysis and testing, Damping Treatments, motor vibration isolation, and other measures, based on vibration analysis and testing results. When debugging scanning electron microscope (SEM) issues, disturbances due to acoustic excitation, floor vibration, control instability, frame resonances, thermal drift, and magnetic fields all superimpose to create a confounding image disturbance. Additionally, each of these disturbances can be aliased. We have years of experience untangling overlapping disturbances involving multiple sources to make the issue understandable and allow for informed decisions when weighing different solution strategies.
Prototyping
We very often get our hands dirty and build proof-of-concept “fixes” on-site or back in our shop to quickly perform a vibration test or an acoustic test of a “design-fix” concept based on our vibration analysis or acoustic noise analysis. We do this prototype testing carefully, drawing on more than 30 years of structural dynamics and acoustics experience as vibration consultants, and always work hard to test and maintain an accurate understanding of the current system dynamics and the boundary conditions associated with our vibration testing and vibration analysis as we make changes.
Tuned mass damper design for biotech optical tool
However, as so often happens to our clients, when quick-and-dirty fixes are attempted by other engineers with little structural dynamics experience, confusion, delay, and uncertainty regarding the design of the experiment often result. A faulty vibration test often leads to the wrong conclusion and drives the wrong course of action, moving the team away from a good solution. Valuable development time is often wasted, and the issue soon becomes an emergency. For a more detailed breakdown of this, see our discussion on Product and Facility Emergencies.
We have the experience, as vibration consultants and acoustic consultants, to quickly analyze past test methodologies and explain to the team what has been done well and what needs improving, tweaking, or additional attention to a particular dynamic parameter. This is important for getting an engineering team on the same page by making sure everyone understands the problem, what has been done, and how to move forward. These unique abilities have brought us long-lasting working relationships with our clients.
Starting From Scratch, The Design Phase, Facility and Product Development
We enjoy being part of the team during the design phase. We help get the design right from the first alpha system onward to avoid last-minute emergencies. We have recently worked in the design phase, performing analytical and experimental vibration analyses on a tabletop scanning electron microscope and a tabletop genomics ID system. We also worked through the design and testing of a cutting-edge biotech imaging system with 25 nm resolution that will operate on upper floors of buildings with lightweight construction. As vibration consultants and acoustic noise consultants, we have quieted noisy dialysis machines, eye surgery equipment, surgical robots, semiconductor imaging tools, and multi-ton solar tracking arrays.
On new Facility Design projects with unique acoustics and vibration needs, we perform the roles of Vibration Consultant, Acoustic Consultant, and EMF Consultant as part of the architect's team. These facilities include state-of-the-art semiconductor research facilities, university research buildings, tech-group collaborative office spaces, and others.
Tuned mass damper design for biotech optical tool
New facility design considerations that require our expertise include HVAC acoustic design, mechanical room design, equipment vibration isolation mounting, sensitive tool placement, floor system design, wall and partition design, sound masking, active cancellation of vibration and acoustic noise, and passive acoustics (added reverberation or added sound absorption in particular frequency bands).
Acoustic Analysis Results Comparing Sound Levels with NC Noise Criteria
As Vibration Consultants and Acoustic Noise Consultants for the design of new High Tech Facilities (such as semiconductor, biotechnology, pharmaceutical, and nanotechnology facilities), we not only have expertise in testing building floor dynamics, vibration, and acoustics, but also understand the needs of the high-resolution, sensitive equipment used in these facilities because we design, fix, and test this equipment. We perform Sensitivity Testing and write specifications for some of the high-resolution imaging and testing systems used in these industries. Additionally, we have spent decades working with facilities teams to troubleshoot facility issues and thus have intimate knowledge of what issues to expect and how to prevent them. We translate that knowledge into design specifications and work with the design team on these critical design details.
Comparison of vibration sensitivity modeling with experimental test data used to evaluate structural modifications for performance improvements
Some of the clients we have worked with over the years as Vibration Consultants now manage engineering groups. These past clients are the ones who most often call us during the product design phase, when we provide valuable input in design reviews, helping identify potential pitfalls and opportunities for significant improvement through adjustments to a few engineering details. Our input during the design phase saves valuable development time and resources and has proven to be key to the success of many product R&D efforts.
In product development, we provide assistance at several points along the product development cycle. First, we provide assistance and guidance in the development of conceptual and detailed designs, often using a combination of analytical, numerical, and Finite Element Modeling methods. Our extensive experience as Vibration Consultants allows us to identify potential pitfalls and find effective solutions as part of your team from the start of the design process. This is critical to staying on budget, on schedule, and meeting performance goals.
Once the prototype has been built, we perform vibration measurements and vibration analysis of the dynamic response of these systems to expected disturbances, including both internal sources of vibration and acoustic noise (such as X-Y stage stopping transients) and external sources (such as floor vibration and HVAC acoustic noise). In addition, determining system resonances through Modal Testing and analysis often provides critical design information. If necessary, the design is then improved by making appropriate changes to the Structural Design, Stage Control, Vibration Isolation, and Damping Treatment.
Effective damping treatment design is possible with a thorough understanding of the structural dynamics of the system
We may also suggest modifications to control system parameters or other system changes. We use our testing and analysis to explain why a system performs as it does and why the modification will improve performance. Our experience as vibration consultants allows us to be both efficient and thorough, minimizing troubleshooting, tool time, and prototype iterations.
For tool vendors, we perform vibration Sensitivity Testing to determine the specifications for allowable levels of Facility Vibration and facility acoustic noise at the system's installation site. We also perform Site Evaluation measurements to verify that the proposed installation site (in the end user's facility) provides an acceptable vibration and acoustic noise environment for the successful operation of the sensitive system. If facility problems are identified at an installation site, we often work with the owner's facilities team to identify and solve the problem or find a suitable alternative site for the system. The solution may involve reducing or isolating the disturbance source, actively canceling the disturbance at the sensitive tool, modifying the floor system, or improving the tool (such as with Tuned Mass Dampers).
Some of the metrology tools that we have worked on as vibration consultants include SEM tools, FIB tools, TEM tools, AFMs (atomic force microscopes), stylus profilometers, wafer steppers, interferometers, electron microscopes, CD-SEM tools, ellipsometers, and SPM tools. These tools are manufactured by companies such as KLA-Tencor, Veeco, Applied Materials, Rudolf Technologies, Nikon, Wyko, Zygo, Sensys, JEOL, Amray, Schlumberger, Therma-Wave, FEI, and Nanometrics.
Whether making a few dynamic measurements, performing a full modal analysis test, or working on the R&D of a new sensitive tool or critical facility, we use our extensive experience to efficiently achieve the project goals. Our founder, Reuben Hale, P.E., started the company over 40 years ago, in 1984. For more information on our engineering team, check out our About Us page. We love what we do and are at the very top of our unique field.
Our extensive Client List represents hundreds of projects, some involving days of work and others lasting many months over the last 40 years. Descriptions of many of our projects can be found in the links on the left-hand side of this website, under the various topics describing our testing, analysis, and design work.